Sindbis virus structural proteins: a bibliography

AU - Mussgay M, Horzinek M
TI - Investigations on complement-fixing subunits of a group A arbo virus (Sindbis).
SO - Virology 1966 Jun;29(2):199-204

AU - Burge BW, Pfefferkorn ER
TI - Isolation and characterization of conditional-lethal mutants of Sindbis virus.
SO - Virology 1966 Oct;30(2):204-13

AU - Burge BW, Pfefferkorn ER
TI - Complementation between temperature-sensitive mutants of Sindbis virus.
SO - Virology 1966 Oct;30(2):214-23

AU - Riccardino N
TI - [On the thermostability of the Sindbis virus]. [Italian]
SO - Ig Mod 1966 Sep-Oct;59(9):607-12

AU - Nagata I, Kimura Y, Matsumoto T, Maeno K, Yoshii S, Nagai Y, Iinuma M
TI - Plaque variants by Sindbis virus.
SO - Arch Gesamte Virusforsch 1967;22(1):78-86

AU - Mussgay M
TI - [On the serological specificity of subunits of 2 arboviruses of group A (Sindbis and WEE)]. [German]
SO - Arch Gesamte Virusforsch 1967;21(2):144-54

AU - Negro Ponzi A
TI - [On the absorption of Sindbis virus on monolayers of chick embryo cells]. [Italian]
SO - Ig Mod 1967;60(11):944-9

AU - Negro-Ponzi A, Martinetto P
TI - [On the formation of plaques by Sindbis virus under different experimental conditions]. [Italian]
SO - Ig Mod 1967;60(11):950-2

AU - Burge BW, Pfefferkorn ER
TI - Temperature-sensitive mutants of Sindbis virus: biochemical correlates of complementation.
SO - J Virol 1967 Oct;1(5):956-62

AU - Fadda G, Turano A, Valenti PL
TI - [Hemolytic activity of the Sindbis virus]. [Italian]
SO - Ig Mod 1968;61(11):824-34

AU - Simpson RW, Hauser RE
TI - Effect of heat on virions of wild-type Sindbis virus and a thermostable mutant.
SO - Virology 1968 Feb;34(2):361-4

AU - Simpson RW, Hauser RE
TI - Basic structure of group A arbovirus strains Middelburg, Sindbis, and Semliki Forest examined by negative staining.
SO - Virology 1968 Feb;34(2):358-61

AU - Strauss JH Jr, Burge BW, Pfefferkorn ER, Darnell JE JR
TI - Identification of the membrane protein and "core" protein of Sindbis virus.
SO - Proc Natl Acad Sci U S A 1968 Feb;59(2):533-7

AU - Faulkner P, Dobos P
TI - Investigations on the formation and interconversion of Sindbis virus hemagglutinins.
SO - Can J Microbiol 1968 Jan;14(1):45-51

AU - Waite MR, Pfefferkorn ER
TI - Effect of altered osmotic pressure on the growth of Sindbis virus.
SO - J Virol 1968 Jul;2(7):759-60

AU - Yin FH, Lockart RZ Jr
TI - Maturation defects in temperature-sensitive mutants of Sindbis virus.
SO - J Virol 1968 Jul;2(7):728-37

AU - Burge BW, Pfefferkorn ER
TI - Functional defects of temperature-sensitive mutants of Sindbis virus.
SO - J Mol Biol 1968 Jul 14;35(1):193-205

AU - Pattyn SR, De Vleesschauwer L
TI - Behaviour of large and small plaque variants of Sindbis and western equine encephalitis viruses in Aedes aegypti.
SO - Ann Soc Belg Med Trop 1969;49(1):63-7

AU - Scheele CM, Pfefferkorn ER
TI - Kinetics of incorporation of structural proteins into Sindbis virions.
SO - J Virol 1969 Apr;3(4):369-75

AU - Scheele CM, Pfefferkorn ER
TI - Inhibition of interjacent ribonucleic acid (26S) synthesis in cells infected by Sindbis virus.
SO - J Virol 1969 Aug;4(2):117-22

AU - Strauss JH Jr, Burge BW, Darnell JE
TI - Sindbis virus infection of chick and hamster cells: synthesis of virus-specific proteins.
SO - Virology 1969 Mar;37(3):367-76

AU - Lab M, Kirn A
TI - [Variations of the thermosensitivity of developing Sindbis virus as a function of the cellular system]. [French]
SO - C R Acad Sci Hebd Seances Acad Sci D 1969 May 28;268(21):2624-7

AU - Yin FH
TI - Temperature-sensitive behavior of hemagglutinin in a temperature-sensitive mutant virion of Sindbis.
SO - J Virol 1969 Oct;4(4):547-8

AU - Bose HR, Carl GZ, Sagik BP
TI - Separation of Sindbis virus plaque-type variants by calcium phosphate chromatography.
SO - Arch Gesamte Virusforsch 1970;29(1):83-9

AU - Bose HR, Brundige MA, Carl GZ, Sagik BP
TI - Peptide composition of sindbis virus variants.
SO - Arch Gesamte Virusforsch 1970;31(3):207-14

AU - Bose HR, Carl GZ, Sagik BP
TI - Purification of two plaque variants of sindbis virus.
SO - Arch Gesamte Virusforsch 1970;31(3):200-6

AU - Burge BW, Huang AS
TI - Comparison of membrane protein glycopeptides of Sindbis virus and vesicular stomatitis virus.
SO - J Virol 1970 Aug;6(2):176-82

AU - Dobos P, Faulkner P
TI - On the infectivity of the Sindbis virus nucleocapsid.
SO - Can J Microbiol 1970 Dec;16(12):1273-83

AU - Burge BW, Strauss JH Jr
TI - Glycopeptides of the membrane glycoprotein of Sindbis virus.
SO - J Mol Biol 1970 Feb 14;47(3):449-66

AU - Strauss JH Jr, Burge BW, Darnell JE
TI - Carbohydrate content of the membrane protein of Sindbis virus.
SO - J Mol Biol 1970 Feb 14;47(3):437-48

AU - Scheele CM, Pfefferkorn ER
TI - Virus-specific proteins synthesized in cells infected with RNA+ temperature-sensitive mutants of Sindbis virus.
SO - J Virol 1970 Mar;5(3):329-37

AU - Waite MR, Pfefferkorn ER
TI - Phospholipid synthesis in Sindbis virus-infected cells.
SO - J Virol 1970 Nov;6(5):637-43

AU - Horzinek M, Mussgay M
TI - Studies on the substructure of togaviruses. I. Effect of urea, deoxycholate, and saponin on the Sindbis virion.
SO - Arch Gesamte Virusforsch 1971;33(3):296-305

AU - David AE
TI - Lipid composition of Sindbis virus.
SO - Virology 1971 Dec;46(3):711-20

AU - Moolten FL, Kibrick S
TI - Enhancement of Sindbis virus infectivity by reduced salt concentration.
SO - Proc Soc Exp Biol Med 1971 Feb;136(2):335-40

AU - Arif B, Faulkner P
TI - Release of viral hemagglutinin and nucleocapsid components after disruption of Sindbis virus with ether.
SO - Can J Microbiol 1971 Feb;17(2):161-9

AU - Compans RW
TI - Location of the glycoprotein in the membrane of Sindbis virus.
SO - Nat New Biol 1971 Jan 27;229(4):114-6

AU - Gaidamovich SY, Zhdanov VM, Krasnobayeva ZN, Melnikova EE, Lavrova NA
TI - Fractionation of Sindbis virus by equilibrium centrifugation.
SO - Acta Virol 1971 Jul;15(4):257-62

AU - Grimes WJ, Burge BW
TI - Modification of Sindbis virus glycoprotein by host-specified glycosyl transferases.
SO - J Virol 1971 Mar;7(3):309-13

AU - Nicoli J, Coulomb P, Meyer F
TI - [Structural proteins of Sindbis virus and translation of the viral genome]. [French]
SO - Ann Inst Pasteur (Paris) 1971 May;120(5):683-97

AU - Harrison SC, David A, Jumblatt J, Darnell JE
TI - Lipid and protein organization in sindbis virus.
SO - J Mol Biol 1971 Sep 28;60(3):533-8

AU - Goldblum N, Ravid R, Hanoch A, Porath Y
TI - Structural and immunologic characteristics of subviral components of Sindbis, eastern equine and western equine encephalitis viruses.
SO - Adv Exp Med Biol 1972;31(0):71-85

AU - Schlesinger MJ, Schlesinger S, Burge BW
TI - Identification of a second glycoprotein in Sindbis virus.
SO - Virology 1972 Feb;47(2):539-41

AU - Pfefferkorn ER, Boyle MK
TI - Selective inhibition of the synthesis of Sindbis virion proteins by an inhibitor of chymotrypsin.
SO - J Virol 1972 Jan;9(1):187-8

AU - Nakamura M, Koga T, Seo M
TI - A large and small plaque variant of sindbis virus obtained by serial passages in tissue culture of chick embryo cells.
SO - Proc Soc Exp Biol Med 1972 Jul;140(3):842-5

AU - Cheban DS, Kitsak VIa
TI - [A change in various biological properties of Sindbis virus as a result of prolonged passage at low temperatures]. [RUSSIAN]
SO - Vopr Virusol 1972 Jul-Aug;17(4):451-3

AU - Zhdanov VM, Gaidamovich SY, Melnikova EE, Krasnobayeva ZN
TI - Biophysical characteristics of Sindbis virion components.
SO - Acta Virol 1972 Mar;16(2):97-102

AU - Ronda-Lain C, Gil-Fernandez C
TI - Enchanced plaque formation by Sindbis and vaccinia viruses under methyl-cellulose overlay in the absence of carbon dioxide.
SO - Acta Virol 1972 Mar;16(2):171-4

AU - Bose HR, Brundige MA
TI - Selective association of Sindbis virion proteins with different membrane fractions of infected cells.
SO - J Virol 1972 May;9(5):785-91

AU - Schlesinger S, Schlesinger MJ
TI - Formation of Sindbis virus proteins: identification of a precursor for one of the envelope proteins.
SO - J Virol 1972 Nov;10(5):925-32

AU - Brown DT, Waite MR, Pfefferkorn ER
TI - Morphology and morphogenesis of Sindbis virus as seen with freeze-etching techniques.
SO - J Virol 1972 Sep;10(3):524-36

AU - Waite MR, Brown DT, Pfefferkorn ER
TI - Inhibition of Sindbis virus release by media of low ionic strength: an electron microscope study.
SO - J Virol 1972 Sep;10(3):537-44

AU - Ravid Z, Goldblum N
TI - Analysis of antigenic activities of enzymatically digested Sindbis virus envelopes.
SO - Intervirology 1973;2(3):152-9

AU - Chudzio T, Inglot AD
TI - Chromatographic purification of the Sindbis virus: comparison of different methods.
SO - Arch Immunol Ther Exp (Warsz) 1973;21(2):227-37

AU - Gil-Fernandez C, Ronda-Lain C, Rubio-Huertos M
TI - Electron microscopic study of Sindbis virus morphogenesis.
SO - Arch Gesamte Virusforsch 1973;40(1):1-9

AU - Pedersen CE Jr, Barrera CR, Sagik BP
TI - Immunochemical studies of Sindbis virus variants.
SO - Arch Gesamte Virusforsch 1973;41(1):29-39

AU - Birdwell CR, Strauss JH
TI - Agglutination of Sindbis virus and of cells infected with Sindbis virus by plant lectins.
SO - J Virol 1973 Apr;11(4):502-7

AU - Birdwell CR, Strauss EG, Strauss JH
TI - Replication of Sindbis virus. 3. An electron microscopic study of virus maturation using the surface replica technique.
SO - Virology 1973 Dec;56(2):420-38

AU - Sefton BM, Burge BW
TI - Biosynthesis of the Sindbis virus carbohydrates.
SO - J Virol 1973 Dec;12(6):1366-74

AU - Brown DT, Gliedman JB
TI - Morphological variants of Sindbis virus obtained from infected mosquito tissue culture cells.
SO - J Virol 1973 Dec;12(6):1534-9

AU - Snyder HW, Sreevalsan T
TI - Proteins specified by Sindbis virus in chick embryo fibroblast cells.
SO - Biochem Biophys Res Commun 1973 Jul 2;53(1):24-31

AU - Schlesinger MJ, Schlesinger S
TI - Large-molecular-weight precursors of sindbis virus proteins.
SO - J Virol 1973 Jun;11(6):1013-6

AU - Pedersen CE Jr, Sagik BP
TI - Sindbis virus maturation.
SO - J Gen Virol 1973 Mar;18(3):375-9

AU - Shenk TE, Stollar V
TI - Defective-interfering particles of Sindbis virus. I. Isolation and some chemical and biological properties.
SO - Virology 1973 May;53(1):162-73

AU - Sefton BM, Wickus GG, Burge BW
TI - Enzymatic iodination of Sindbis virus proteins.
SO - J Virol 1973 May;11(5):730-5

AU - Weiss B, Schlesinger S
TI - Defective interfering passages of Sindbis virus: chemical composition, biological activity, and mode of interference.
SO - J Virol 1973 Oct;12(4):862-71

AU - Inglot AD, Chudzio T, Albin M
TI - Analysis of Sindbis virus and its soluble antigens in preparations concentrated by precipitation with polyethylene glycol or ammonium sulfate.
SO - Acta Virol 1973 Sep;17(5):416-25

AU - Zhdanov VM, Azadova NB, Kopel'man RN
TI - [The biophysical characteristics of viral structures in chronic Sindbis infection]. [RUSSIAN]
SO - Vopr Virusol 1973 Sep-Oct;18(5):524-8

AU - Schlesinger S, Weiss B, Goran D, Schlesinger M, Cancedda R
TI - Formation of RNA and protein in cells infected with standard and defective Sindbis virus.
SO - Med Microbiol Immunol (Berl) 1974;160(4):311-29

AU - Jones KJ, Waite MR, Bose HR
TI - Cleavage of a viral envelope precursor during the morphogenesis of Sindbis virus.
SO - J Virol 1974 Apr;13(4):809-17

AU - Birdwell CR, Strauss JH
TI - Replication of Sindbis virus. IV. Electron microscope study of the insertion of viral glycoproteins into the surface of infected chick cells.
SO - J Virol 1974 Aug;14(2):366-74

AU - Atkins GJ, Samuels J, Kennedy SI
TI - Isolation and preliminary characterization of temperature-sensitive mutants of Sindbis virus strain AR339.
SO - J Gen Virol 1974 Dec;25(3):371-80 S

AU - Sefton BM, Gaffney BJ
TI - Effect of the viral proteins on the fluidity of the membrane lipids in Sindbis virus.
SO - J Mol Biol 1974 Dec 5;90(2):343-58

AU - Snyder HW, Sreevalsan T
TI - Proteins specified by Sindbis virus in HeLa cells.
SO - J Virol 1974 Feb;13(2):541-4

AU - Schluter B, Bellomy B, Brown A
TI - Pathogenesis of temperature-sensitive mutants of sindbis virus in the embryonated egg. I. Characterization and kinetics of viral multiplication.
SO - Infect Immun 1974 Jan;9(1):68-75

AU - Schluter B, Brown A
TI - Pathogenesis of temperature-sensitive mutants of sindbis virus in the embryonated egg. II. Control of the infectious process.
SO - Infect Immun 1974 Jan;9(1):76-80

AU - Waite MR, Lubin M, Jones KJ, Bose HR
TI - Phosphorylated proteins of Sindbis virus.
SO - J Virol 1974 Jan;13(1):244-6

AU - Tan KB, Sokol F
TI - Virion-bound protein kinase in Semliki forest and Sindbis viruses.
SO - J Virol 1974 Jun;13(6):1245-53

AU - Simmons DT, Strauss JH
TI - Translation of Sindbis virus 26 S RNA and 49 S RNA in lysates of rabbit reticulocytes.
SO - J Mol Biol 1974 Jun 25;86(2):397-409

AU - Brown F, Smale CJ, Horzinek NC
TI - Lipid and protein organization in vesicular stomatitis and Sindbis viruses.
SO - J Gen Virol 1974 Mar;22(3):455-8

AU - Pierce JS, Strauss EG, Strauss JH
TI - Effect of ionic strength on the binding of Sindbis virus to chick cells.
SO - J Virol 1974 May;13(5):1030-6

AU - Cancedda R, Schlesinger MJ
TI - Formation of Sindbis virus capsid protein in mammalian cell-free extracts programmed with viral messenger RNA.
SO - Proc Natl Acad Sci U S A 1974 May;71(5):1843-7

AU - Raikova AP, Khutorestskaia NV, Tsilinskii IaIa, L'vov DK, Klimenko SM
TI - [Morphogenesis of Sindbis virus in intestinal and salivary gland cells of the mosquito Aedes aegypti]. [RUSSIAN]
SO - Vopr Virusol 1974 May-Jun;19(0):283-9

AU - Hirschberg CB, Robbins PW
TI - The glycolipids and phospholipids of Sindbis virus and their relation to the lipids of the host cell plasma membrane.
SO - Virology 1974 Oct;61(2):602-8

AU - Birdwell CR, Strauss JH
TI - Distribution of the receptor sites for Sindbis virus on the surface of chicken and BHK cells.
SO - J Virol 1974 Sep;14(3):672-8

AU - Cancedda R, Swanson R, Schlesinger MJ
TI - Effects of different RNAs and components of the cell-free system on in vitro synthesis of Sindbis viral proteins.
SO - J Virol 1974 Sep;14(3):652-63

AU - Sefton BM, Keegstra K
TI - Glycoproteins of Sindbis virus: priliminary characterization of the oligosaccharides.
SO - J Virol 1974 Sep;14(3):522-30

AU - Simmons DT, Strauss JH
TI - Replication of Sindbis virus. V. Polyribosomes and mRNA in infected cells.
SO - J Virol 1974 Sep;14(3):552-9

AU - Cancedda R, Swanson R, Schlesinger MJ
TI - Viral proteins formed in a cell-free rabbit reticulocyte system programmed with RNA from a temperature-sensitive mutant of Sindbis virus.
SO - J Virol 1974 Sep;14(3):664-71

AU - Fine DL, Allen WP, Wilkins LB
TI - Features of cross protection between Sindbis and Venezuelan equine encephalitis viruses in mice--relationship of route of immunization to protection.
SO - J Gen Virol 1974 Sep;24(3):401-8

AU - Wagner B, Veckenstedt A, Wagner M
TI - Crystalline arrays of nucleocapsids in Sindbis virus-infected L cells.
SO - Intervirology 1975;5(1-2):103-7

AU - Schwobel W, Speiser C, Warnke MK
TI - Changes of the cell type of BHK-21 lines by persistent Sindbis virus.
SO - Zentralbl Bakteriol [Orig A] 1975;231(1-3):42-6
AB - Persistent infection by Sindbis virus (SV) can be induced in cultures of BHK-21 cells. In a persistently infected cell line only 5% of the cells produced virus. Virus titers in the medium reached 10(5) PFU per ml. A persistent infection could be eliminated from cultures by seeding at most 100 cells per bottle. Compared with the original line decontaminated lines differed in several properties. After infection with SV ten times less virus was released into the medium, and an infection persisted without producing periodic cell destructions as observed in establishing a persistent infection in the original line. In decontaminated lines plaques formed by different viruses were either not visible or smaller than those in normal cells. Persistently infected as well as decontaminated lines had lost three chromosomes. The altered cell type of persistently infected lines apparently originated by selection of a cell mutant which was not destroyed by SV. Results suggested that a small number of cells susceptible to the virus continuously arises from the population of altered cells, and that virus infection is transmitted and maintained in the cultures by these sensitive cells.

AU - Chudzio T, Inglot AD
TI - Biological properties of three spontaneous mutants of Sindbis virus.
SO - Arch Immunol Ther Exp (Warsz) 1975;23(1):113-29

AU - Feinsod FM, Spielman A, Waner JL
TI - Neutralization of a togavirus by antivector antisera.
SO - Ann N Y Acad Sci 1975;266:251-4
AB - An A. aegypti-propagated togavirus (Sindbis) is neutralized by antisera to both whole-body extracts and to salivary fluid of the vector mosquito. Virus propagated in Vero cells is not neutralized by such antisera. Neutralizing activity resides in the immune globulin fraction of sera. Sera from animals injected with adjuvant neutralized neither virus propagated in mosquitoes nor virus obtained from Vero cells. Although neutralizing titers were low, such activity may protect, to some degree, vertebrate hosts normally exposed to vector antigens.

AU - Symington J, Schlesinger MJ
TI - Isolation of a Sindbis virus variant by passage on mouse plasmacytoma cells.
SO - J Virol 1975 Apr;15(4):1037-41
AB - A variant of Sindbis virus has been isolated by growing a stock of virus, previously passaged on chicken embryo cells, in mouse plasmacytoma (MOPC 315) cells in suspension culture. An indirect immunofluorescence test and infective center assay showed that only a small fraction of cells could be infected by the stock wild-type virus, but that the population of virus accumulating after a few passages on the mouse cells had host-range properties distinct from the stock virus. The mouse-passaged virus retained its virulence for the original host and back-passaging of this virus on chicken cells did not change its newly acquired properties. Thus, this variant appears to be a genetically distinct form of Sindbis that adsorbs to and grows much better than the stock virus on several types of mouse cells including cultures of mouse macrophages.

AU - Stollar V
TI - Immune lysis of Sindbis virus.
SO - Virology 1975 Aug;66(2):620-4

AU - Wagner B, Veckenstedt A, Wagner M
TI - Sindbis virus infected L cells studied by ferritin-labelled antibodies.
SO - Zentralbl Bakteriol [Orig A] 1975 Dec;233(4):431-9
AB - Sindbis virus infected L cells were examined by immunoferritin technique at different times after infection. Initially virus-specific antigens appeared diffusely distributed in the cytoplasm and at the surface of vacuoles. Later on, both labelled nucleocapsids surrounding vacuoles and mature virus within their lumen were demonstrated. Maturation of virus occurred predominantly at the periphery of cells, and that mainly by budding from cell processes. The appearance of big crystals consisting of nucleocapsids is a typical event of late stages of infection. These findings are compared with corresponding fluorescent antibody results.

AU - Mooney JJ, Dalrymple JM, Alving CR, Russell PK
TI - Interaction of Sindbis virus with liposomal model membranes.
SO - J Virol 1975 Feb;15(2):225-31
AB - Radiolabeled Sindbis virus was found to bind to protein-free lipid model membranes (liposomes) derived from extracts of sheep erythrocytes. The virus interaction was dependent on initial pH, and the range of pH dependence (pH 6.0 to 6.8) was the same as the observed with virus-dependent hemagglutination. After the initial interaction, pH changes no longer influenced the virus binding to liposomes. Virus bound to liposomes prepared from a mixture of erythrocyte phospholipids, but the binding was greatly diminished when either cholesterol or phosphatidylethanolamine was omitted from the liposomal lipid mixture. It was concluded that phospholipids and cholesterol, in a bilayer configuration, may be sufficient for specific virus binding in the absence of membrane protein.

AU - Duda E, Schlesinger MJ
TI - Alterations in Sindbis viral enbelope proteins by treating BHK cells with glucosamine.
SO - J Virol 1975 Feb;15(2):416-9

AU - Sefton BM
TI - Virus-dependent glycosylation.
SO - J Virol 1975 Jan;17(1):85-93
AB - The oligosaccharides of the membrane glycoproteins of Sindbis virus, vesicular stomatitis virus, and Rous sarcoma virus were compared on the basis of apparent size and sugar composition. It appears that each virus acquires a different set of oligosaccharides during growth in a single type of cell.

AU - Schlesinger S, Gottlieb C, Feil P, Gelb N, Kornfeld S
TI - Growth of enveloped RNA viruses in a line of chinese hamster ovary cells with deficient N-acetylglucosaminyltransferase activity.
SO - J Virol 1975 Jan;17(1):239-46
AB - Sindbis and vesicular stomatitis viruses were grown in a line (termed 15B) of Chinese hamster ovary (CHO) cells that is deficient in a specific UDP-N-acetyl-glucosamine:glycoprotein N-acetylglucosaminyltransferase. Both viruses replicated normally in the cell line, but the glycoproteins of the released virus migrated faster on sodium didecyl sulfate-polyacrylamide gels than did glycoproteins of virus grown in parent CHO cells. Digestion of the viral glycoproteins with Pronase followed by gel filtration demonstrated that the glycoproteins with Pronase followed by gel filtration demonstrated that the glycopeptides of Sinbis-15B virus were much smaller than the glycopeptides of Sindbis-CHO virus. In addition, Sindbis-15B viral glycopeptides but not Sindbis-CHO viral glycopeptides contained terminal alpha-mannose residues as shown by their susceptibility to alpha-mannosidase digestion. These findings demonstrate that the oligosaccharide units of the glycoproteins of vesicular stomatitis and Sinbis viruses are altered when the viruses are grown in 15B cells. We conclude that the N-acetylglucosaminyltransferase that is missing in 15B cells normally participates in the biosynthesis of the oligosaccharide units of the viral glycoproteins, and in the absence of this enzyme incomplete oligosaccharide chanis are produced. Viruses released from 15B cells appear to retain full infectivity; Sindbis-15B virus, however, showed a significant decrease in hemagglutination titer compared with that of Sindbis-CHO virus.

AU - Kaluza G, Kraus AA, Rott R
TI - Inhibition of cellular protein synthesis by simultaneous pretreatment of host cells with fowl plague virus and actinomycin D: a method for studying early protein synthesis of several RNA viruses.
SO - J Virol 1975 Jan;17(1):1-9
AB - A method is described for analysis of viral protein synthesis early after infection when minute amounts of viral proteins are effectively concealed by large amounts of produced host-specific proteins. The method is superior to a radioimmune assay, since all virus-induced proteins can be measured independent of their immunological reactivity. Host-specific protein synthesis can be suppressed by infection with fowl plague virus. Addition of actinomycin C 1.25 h postinfection does not prevent this suppression, but it does block effectively the formation of fowl plague virus-specific proteins. Such cells synthesize only small amounts of cellular proteins, as revealed by polyacrylamide electrophoresis. They can be superinfected with several different enveloped viruses, however, without significant diminution of virus yeilds. In pretreated cells the eclipse is shortened for Semliki Forest virus, Sindbis virus, and vesicular stomatitis virus, but prolonged for Newcastle disease virus. The onset of protein synthesis, specific for the superinfecting virus, could be clearly demonstrated within 1 h after superinfection. At this time, in cells superinfected with Semliki Forest virus, great amounts of NSP 75 (nonstructural protein; molecular weight, 75 X 10(3)) and reduced amounts of the core protein C could be deomonstrated. The precursor glycoprotein NSP 68 is followed by a new polypeptide, NSP 65: three proteins with molecular weights exceeding 100 X 10(3) were observed which are missing later in the infectious cycle. Similar results were obtained after superinfection with Sindbis virus. The formation of a new polypeptide with a molecular weight of about 80 X 10(3) was detected. After superinfection with vesicular stomatis virus or Newcastle disease virus the formation of new proteins, characteristic for the early stage of infeciton, was not observed.

AU - von Bonsdorff CH, Harrison SC
TI - Sindbis virus glycoproteins form a regular icosahedral surface lattice.
SO - J Virol 1975 Jul;16(1):141-5
AB - Electron micrographs of negatively stained Sindbis virus particles show that the glycoproteins are organized with trimer clustering in a T = 4 icosahedral surface lattice.

AU - Hughes F, Pedersen CE
TI - Paramagnetic spin label interactions with the envelope of a group A arbovirus. Lipid organization.
SO - Biochim Biophys Acta 1975 Jun 11;394(1):102-10
AB - Electron paramagnetic resonance observations were made on nitroxide spin- labeled molecules which were bound to the TC-83 vaccine strain of Venezuelan equine-encephalomyelitis virus. Paramagnetic resonance parameters derived from the observations and their dependence on sample temperature were similar but not identical to those which have been reported for these labels dissolved in lipid bilayer membranes of mammalian and bacterial origin. The data has a mechanical rigidity substantially greater than that of bilayers in cellular membranes. A model is presented which assumes the location of the lipid bilayer outside the nucleoprotein capsid and inside a spherical layer of envelope proteins. The model is in accord with Harrison's X-ray diffraction results for Sindbis virus. The model is discussed in terms of its implications with respects to the role played by lipid in viral maturation and infectivity.

AU - Feinsod FM, Spielman A, Waner JL
TI - Neutralization of Sindbis virus by antisera to antigens of vector mosquitoes.
SO - Am J Trop Med Hyg 1975 May;24(3):533-6
AB - Sindbis virus harvested from infected cultures of Vero cells and from Aedes aegypti mosquitoes was used in neutralization tests with sera obtained from guinea pigs immunized with ground A. aegypti and from guinea pigs repetitively bitten by mosquitoes. Employing these antisera, more mosquito-propagated virus was neutralized than was virus grown in cultures of Vero cells. The neutralizing activity resided in the immune globulin fraction and may reflect the production of antibody to vector antigens on the viral envelope.

AU - Vance DE, Lam J
TI - Sindbis virus inhibits phosphatidylcholine biosynthesis in BHK-21 cells.
SO - J Virol 1975 Oct;16(4):1075-6
AB - Sindbis virus inhibits the incorporation of [methyl-3H]choline into the phospholipids of BHK-21 cells and also inhibits the activity of the enzyme that catalyzes the final reaction involved in phosphatidylcholine biosynthesis (cytidine diphosphate-choline:1,2-diacylglycerol cholinephosphotranferase; EC 2.7.8.2).

AU - Duda E
TI - The effect of canavanine on the capsid protein of Sindbis virus.
SO - Med Biol 1975 Oct;53(5):365-7
AB - In the presence of the arginine analogue canavanine, Sindbis virus-infected BHK 21 cells synthesize a capsid protein of somewhat larger molecular weight than that of controls. This protein can also be seen in short pulse-labelled cells, and probably represents a precursor of the normal capsid protein. In our experiments canavanine had no effect on the viral envelope proteins, and the canavanine containing capsid protein formed nucleocapsids and virus particles as well as normal capsid protein does.

AU - Pinter A, Compans RW
TI - Sulfated components of enveloped viruses.
SO - J Virol 1975 Oct;16(4):859-66
AB - The glycoproteins of several enveloped viruses, grown in a variety of cell types, are labeled with 35SO4(-2), whereas the nonglycosylated proteins are not. This was shown for the HN and F glycoproteins of SV5 and Sendai virus, the E1 and E2 glycoproteins of Sindbis virus, and for the major glycoprotein, gp69, as well as for a minor glycoprotein, gp52, of Rauscher leukemia virus. The minor glycoprotein of Rauscher leukemia virus is more highly sulfated, with a ratio of 35SO4- [3H]glucosamine about threefold greater than that of gp69. The G protein of vesicular stomatitis virus was labeled when virions were grown in the MDBK line of bovine kidney cells, although no significant incorporation of 35SO4(-2) into this protein was observed in virions grown in BHK21-F line of baby hamster kidney cells. In addition to the viral glycoproteins, sulfate was also incorporated into a heterogenous component with an electrophoretic mobility lower than that of any labeled with 35SO4(-2) and [3H]leucine, this component had a much greater 35S-3H ratio than any of the viral polypeptides and thus could not represent aggregated viral proteins. This material is believed to be a cell-derived mucopolysaccharide and can be removed from virions by treatment with hyaluronidase without affecting the amount of sulfate present on the glycoproteins.

AU - Duda E
TI - Effect of cycloheximide on viral precursor protein B in Sindbis virus-infected BHK cells.
SO - Med Biol 1975 Oct;53(5):368-71
AB - The possible role of B protein, a postulated precursor of viral envelope proteins was studied in Sindbis virus-infected BHK cells. Although tryptic digestion of the B protein produces tryptic peptides of the viral envelope proteins it seems unlikely that B molecules accumulated in the cytoplasm of infected cells are subsequently cleaved into structural proteins. We suggest that if B is really the precursor of E1 and PE2 viral envelope proteins, the cleavage takes place on the ribosomes during the synthesis of the second part of the B protein. Low concentrations of cycloheximide completely blocked the synthesis of B protein but did not inhibit the synthesis of viral structural proteins.

AU - Gliedman JB, Smith JF, Brown DT
TI - Morphogenesis of Sindbis virus in cultured Aedes albopictus cells.
SO - J Virol 1975 Oct;16(4):913-26
AB - Cultured mosquito cells were found to produce Sindbis virus nearly as efficiently as BHK-21 cells at 28 C. In virtually all of the cells observed in the electron microscope, virus morphogenesis was found to occur within complex vesicular structures which developed after viral infection. Viral nucleocapsids were first seen in these vesicles and appeared to be enveloped within these structures. The process of envelopment within these inclusions differed in some respects from the process previously described for the envelopment of nucleocapsids at the plasma membrane of vertebrae cells. Free nucleocapsids were only rarely seen in the cytoplasm of infected mosquito cells, and budding of virus from the cell surface was detected so infrequently that this process of virus production could not account for the amount of virus produced by the infected cells. The vast majority of extracellular virus was produced by the fusion of the virus-containing vesicles with the plasma membrane releasing mature virions and membrane nucleocapsid complexes in various stages of development.

AU - Johnston RE, Tovell DR, Brown DT, Faulkner P
TI - Interfering passages of Sindbis virus: concomitant appearance of interference, morphological variants, and trucated viral RNA.
SO - J Virol 1975 Oct;16(4):951-8
AB - Serial passage of Sindbis at high multiplicities of infection resulted in cyclical variations in virus titer. Decreases in virus titer were correlated with the appearance of smaller-sized virions, interference and truncated viral RNA. The smaller particles were 37 nm in diameter, exclusive of the hemagglutinin spikes as compared with a diameter of 50 nm for standard virions. Passages which contained 37-nm partilces also interfered with infectious center formation by standard, plaque-purified virus. Polyacrylamide gel analysis of RNA isolated from virions present in interfering passages demonstrated the sequential appearance of three RNA species smaller than standard RNA with approximate molecular weights of 3.3 X 106, 2.7 X 106, and 2.2 X 106. The 3.3 X 106 RNA was evident in passage 5, by passage 8 both the 3.3 X 106 and 2.7 X 106 RNAs were present, and by passage 13 all three were present with the 2.2 X 106 RNA predominating.

AU - Schlesinger MJ
TI - Function of Sindbis virus 49S and 26S RNAs in in vitro protein synthesizing systems. A summary.
SO - Med Biol 1975 Oct;53(5):380-2

AU - Cancedda R, Villa-Komaroff L, Lodish HF, Schlesinger M
TI - Initiation sites for translation of sindbis virus 42S and 26S messenger RNAs.
SO - Cell 1975 Oct;6(2):215-22
AB - Sindbis virus 26S RNA is the principal species of virus-specific RNA found in the infected cell; it is derived from a one third segment of virion 42S RNA. When translated in cell-free extracts from mouse ascites cells or rabbit reticulocytes, 26S RNA directed the synthesis primarily of the 33,000 dalton virus capsid protein, and the protein products were in the form of free peptides rather than peptidyl-tRNA. In contrast, the polypeptides synthesized in either extract in response to Sindbis virus 42S RNA were heterogeneous, ranging in molecular weight from 33,000 to 190,000, and were largely in the form of peptidyl-tRNA. The number of independent initiation sites on the 26S and 42S RNAs was determined by analyzing a tryptic digest of reaction products labeled with yeast N-formyl-35S-methionyl-tRNAFmet. The 26S RNA appeared to contain a single initiation site, and this site could also be found in varying amounts in different preparations of 42S RNA. However, a second initiation site, distinct from that of 26S RNA, was the major site in 42S virion RNA. These results suggest that 42S virion RNA contains two potential sites for initiation of protein synthesis. Only one of these may be active, however, and it is postulated that the second site functions primarily, if not exclusively, in the subgenomic 26S RNA species. In this regard, Sindbis virus 42S RNA may represent a novel form of a eucaryotic messenger RNA.

AU - Schlesinger RW
TI - Sindbis virus replication in vertebrate and mosquito cells: an interpretation. [Review]
SO - Med Biol 1975 Oct;53(5):295-301
AB - This paper summarizes recent comparative studies of Sindbis virus (SV) replication in cultured Aedes albopictus (A. albo) or (A. aegypti (A. aeg) and BHK21 or chick embryo (CEF) cells. 1. Viral growth kinetics and yields are similar in A. albo cells at 28 degress C and in vertebrate cells at 37 degrees C. A. albo exhibit no CPE and yield persistenetly infected cultures. 2. SV grown in A. albo cells lacks sialic acid but is antigenically and in terms of particle/PFU or particle/HAU ratios equivalent to SV derived from vertebrate cells. The contrast to VSV in the latter respect is discussed. 3. SV from persistently infected A. albo or A. aeg cells is temperature-sensitive, thermolabile, and produces small plaques. Partial characterization of these mutants, of RNA associated with their replication, and their high reversion rate to ts+ upon serial undiluted passage in BHK21 cells are presented. 4. Host dependent differences in the generation of defective-interfering (DI) SV particles and of low molecular weight viral RNA species have been observed upon undiluted serial passages in BHK21 and CEF. In contrast, serial passage in A. albo cells appears not to produce DI particles or small RNA species nor do these cells "recognize" as such DI particles from BHK21 cells. 5. Possible implications of these observations fro the natural life cycle of arthropod-borne togaviruses are discussed. [References: 23]

AU - Frisch-Niggemeyer W
TI - Purification of togavirus haemagglutinins by chromatography on controlled pore glass.
SO - Acta Virol 1975 Sep;19(5):381-6
AB - Purified preparations of haemagglutinins from Sindbis, West Nile and tick-borne encephalitis (TBE) viruses could be obtained from infected mouse brains by alkaline extraction, precipitation with protamine and chromatography on polyethylene glycol-coated controlled pore glass with 242 A pore diameter.

AU - Keegstra K, Sefton B, Burke D
TI - Sindbis virus glycoproteins: effect of the host cell on the oligosaccharides.
SO - J Virol 1975 Sep;16(3):613-20
AB - Sindbis virus was grown in four different host cells and the carbohydrate portions of the glycoproteins were analyzed. Sindbis virus grown in BHK-21 cells has more sialic acid and galactose than Sindbis virus grown in chicken embryo cells. In other respects the carbohydrates from virus grown in these two hosts are very similar. Sindbis virus grown either in chick cells transformed by Rous sarcoma virus or in BHK cells transformed by polyoma virus was also examined. In comparisons of virus from normal and transformed cells, differences in the amount of sialic acid were observed; but otherwise the carbohydrate structures appeared basically similar. The growth conditions used for the host cell also affected the degree of completion of the carbohydrate chains of the viral glycoproteins.

AU - Brawner TA, Steglich C, Sagik BP
TI - Genetic exclusion and stable complementation of Sindbis virus.
SO - Arch Virol 1976;50(3):177-87
AB - In an effort to enhance genetic interactions by eliminating spatial or physical barriers between variants of Sindbis virus MgCl2 was used to aggregate infecting viral particles. Mixing viral samples in a 1:1 ratio with 0.5 M MgCl2 produced maximal reduction in plaque forming units (PFU) with minimal cell damage due to MgCl2. Aggregate size was determined to be about 7 PFU. Samples taken at 3,5 and 10 hours after infection with mixed aggregates composed of large and small plaque forming virus indicated that only one type of genome was represented among the progeny particles. In addition, aggregation enhanced complementation and the progeny were stable after several cycles of sonication and passage.

AU - Burke DJ, Keegstra K
TI - Purification and composition of the proteins from Sindbis virus grown in chick and BHK cells.
SO - J Virol 1976 Dec;20(3):676-86
AB - Procedures are described for the purification of the Sindbis virus structural proteins. The amino acid and carbohydrate compositions of the purified proteins are presented for virus grown in BHK-21/13 and chicken embryo cells. Glycoprotein E1 from virus grown in BHK cells is deficient in a mannose-rich glycopeptide found on that glycoprotein when virus is grown in chicken embryo cells. The complex glactose-containing glycopeptides appear similar for virus grown in both hosts. However, when virus is grown in BHK cells, both glycoproteins are enriched in those glycopeptides containing more sialic acid. Since the two viral glycoproteins are difficult to separate cleanly during purification, it is suggested that there may be strong, but noncovalent, interactions between glycoproteins E1 and E2. It is also suggested that there may be an interaction between glycoprotein E2 and a component of the nucleocapsid.

AU - Stollar V, Stollar BD, Koo R, Harrap KA, Schlesinger RW
TI - Sialic acid contents of sindbis virus from vertebrate and mosquito cells. Equivalence of biological and immunological viral properties.
SO - Virology 1976 Jan;69(1):104-15

AU - Dalrymple JM, Schlesinger S, Russell PK
TI - Antigenic characterization of two sindbis envelope glycoproteins separated by isoelectric focusing.
SO - Virology 1976 Jan;69(1):93-103

AU - Iakhno MA, Azadova NB, Zakstel'skaia LIa, Gushchin BV, Klimenko SM
TI - [Identification of a hemadsorbing agent discovered in uninfected mouse L cell cultures and also the same cultures chronically infected with Sindbis virus]. [RUSSIAN]
SO - Vopr Virusol 1976 Jan-Feb;(1):50-6
AB - Electron microscope examinations of continuous lines of mouse L cells, both uninfected (L-init) and chronically infected with Sindbis virus (L-SV) revealed accumulations of ribonucleoprotein strands and virions corresponding by their parameters to paramyxoviruses in the cytoplasms of the cells. Further studies showed L-init and L-SV cell lines to have a manifest hemadsorption effect which could be completely inhibited by antiserum to parainfluenza SV5 virus. Immunofluorescence procedures detected intensive fluorescence in the cytoplasm of these cells which was observed only after treatment of the cells with antiserum to SV5 virus. In response to inoculation of cell homogenates of continuous L-init and L-SV cultures guinea pigs developed antihemagglutinating antibody to simian parainfluenza SV5 virus. On the basis of these results it may be assumed that virus-specific structures and viruses identical by their parameters to paramyxoviruses observed in electron microscope examinations of continuous mouse L-init and L-SV cells are simian parainfluenza SV5 virus.

AU - Moore NF, Barenholz Y, Wagner RR
TI - Microviscosity of togavirus membranes studied by fluorescence depolarization: influence of envelope proteins and the host cell.
SO - J Virol 1976 Jul;19(1):126-35
AB - The microviscosities of the hydrophobic regions of the membranes of intact Semliki forest and Sindbis viruses grown on BHK-21 cells, of liposomes derived from the extracted viral lipids, and of protease-treated virions were measured by fluorescence depolorization using the fluorescence probe 1, 6-diphenyl-1,3,5-hexatriene. The intact virus membranes were found to have a higher microviscosity than did virus-derived liposomes, indicating the viral envelope proteins contribute to microviscosity. However, protease-treated virus, devoid of protruding spikes but with residual lipophilic peptide tails, was found to have a microviscosity more similar to that of the intact virus than to that of protein-free liposomes. Sindbis virus grown in BHK-21 cells at 37 C had a much higher microviscosity than did Sindbis virus grown on Aedes albopicuts cells at 22 C. Sindbis virus grwon in A. albopictus and BHK-21 cells also gave higher microviscosity values than did the intact host cells. These data indicate that both the virion proteins and the cellular lipids selected during viral growth and maturation contribute to the increased microviscosity of togavirus membranes.

AU - Sly WS, Lagwinska E, Schlesinger S
TI - Enveloped virus acquires membrane defect when passaged in fibroblasts from I-cell disease patients.
SO - Proc Natl Acad Sci U S A 1976 Jul;73(7):2443-7
AB - Sindbis virus obtained after passage on human fibroblasts from patients with I-cell disease (mucolipidosis II) and called I-cell virus differed from Sindbis virus obtained from chick fibroblasts or from normal human fibroblasts in two ways: (1) The I-cell virus was extremely unstable to freezing and thawing, (2) The I-cell virus showed greatly exaggerated sensitivity to inactivation by Triton X-100. Sindbis virus from fibroblasts from two patients with mucolipidosis III, a milder form of I-cell disease, showed similar, though milder, freeze-sensitivity. When freeze-sensitive I-cell virus was passaged once in mouse L-cells or normal human fibroblasts, the virus was no longer abnormal. The viral glycoproteins of I-cell virus were not distinguishable from viral glycoproteins of controls by sodium dodecyl sulfate gel electrophoresis. Gel filtration of the glycopeptides suggested small differences in two of the four glycopeptides. These findings indicate that Sindbis virus is phenotypically altered when grown on I-cell fibroblasts. These alterations must be attributed to viral envelope components derived from the host plasma membrane (membrane lipids) or to alterations in viral envelope glycoproteins. In either case, the alterations appear related to the genetic defect in I-cell fibroblasts. From these results it is clear that enveloped viruses can be useful to demonstrate and to analyze membrane defects in certain human diseases. The phenotypically altered viruses may, in turn, provide probes for studying the functional relationships of virus membrane components.

AU - Atkins GJ
TI - The effect of infection with Sindbis virus and its temperature-sensitive mutants on cellular protein and DNA synthesis.
SO - Virology 1976 Jun;71(2):593-7

AU - Stoffel W, Sorgo W
TI - Asymmetry of the lipid-bilayer of Sindbis virus.
SO - Chem Phys Lipids 1976 Oct;17(2-3 SPEC NO):324-35
AB - The organization of the lipid bilayer of the enveloped Sindbis virus has been studied. In the model membrane which consists only of two virus specific glycoproteins and host derived lipids the latter were radioactively labelled with 14C-palmitic acid by prelabelling their BHK 21 host cell lipids. The purified virus particles were submitted to neuramidase, bromelain and combromelain-neuraminidase treatment. It could be demonstrated that N-acetyl neuraminic acid residue of the total hematoside present in the virion is hydrolyzed by neuraminidase leaving the particles fully intact. Proteolysis of the spikes leads to particle aggregation yet an unchanged hematoside content. This was fully transformed into ceramidelactoside by subsequent neuraminidase treatment. The analyses of the ceramide species present in hematoside of the control particles and ceramidelactoside derived thereof by neuraminidase hydrolysis are in very close agreement. From these experiments it is concluded that all hematoside molecules are organized in the outer half of the bilayer of the envelope.

AU - Strauss EG, Lenches EM, Strauss JH
TI - Mutants of sindbis virus. I. Isolation and partial characterization of 89 new temperature-sensitive mutants.
SO - Virology 1976 Oct 1;74(1):154-68

AU - Bracha M, Schlesinger MJ
TI - Defects in RNA+ temperature-sensitive mutants of Sindbis virus and evidence for a complex of PE2-E1 viral glycoproteins.
SO - Virology 1976 Oct 15;74(2):441-9

AU - Renz D, Brown DT
TI - Characteristics of Sindbis virus temperature-sensitive mutants in cultured BHK-21 and Aedes albopictus (Mosquito) cells.
SO - J Virol 1976 Sep;19(3):775-81
AB - A number of the temperature-sensitive mutants of Sindbis virus originally isolated and characterized by Burge and Pfefferkorn (1966, 1968) were reexamined for their abilities to grow and complement one another in cultured BHK-21 and Aedes albopictus (mosquito) cells. The response of the mutants to conditions of high and low temperature was similar in cultured cells of both the vertebrate and invertebrate hosts. Complementation experiments in BHK-21 cells produced growth patterns similar to those described by Burge and Pfefferkorn for chicken embryo fibroblast cells (1966) and placed the mutants into six nonoverlapping complementation groups. When examined in the cultured mosquito cells, only three of the nine mutants used in this study demonstrated complementation under a variety of experimental conditions. Homologous interference experiments demonstrated that the unusual patterns of complementation obtained in the A. albopictus cells did not result from an inefficient infection of the invertebrate cells by the mutants.

AU - Keegstra K, Burke D
TI - Comparison of the carbohydrate of Sinbis virus glycoproteins with the carbohydrate of host glycoproteins.
SO - J Supramol Struct 1977;7(3-4):371-9
AB - The carbohydrate portions of the Sindbis virus glycoproteins were compared with the carbohydrate portions of cell surface glycoproteins from uninfected host cells. Comparisons of the size of glycopeptides were made using gel filtrations. Comparisons of sugar linkages were made by methylation analysis. The conclusion was that the Sindbis carbohydrate is similar to a portion of the host carbohydrate. Thus, the Sindbis carbohydrate structures appear to be structures normally made in the uninfected host cell, but which are added to the Sindbis glycoproteins in virus-infected cells.

AU - Sefton BM
TI - Immediate glycosylation of Sindbis virus membrane proteins.
SO - Cell 1977 Apr;10(4):659-68
AB - The mechanism by which the membrane proteins of Sindbis virus are initially glycosylated during growth of the virus in chick cells was studied. The experiments suggest strongly that the two viral glycoproteins are glycosylated before release from the polysome, and that this glycosylation involves transfer of a large 1800 dalton oligosaccharide to the polypeptide chains. The donor of the oligosaccharide is most probably a lipid.

AU - Dubin DT, Stollar V, Hsuchen CC, Timko K, Guild GM
TI - Sindbis virus messenger RNA: the 5'-termini and methylated residues of 26 and 42 S RNA.
SO - Virology 1977 Apr;77(2):457-70

AU - Wagner M, Veckenstedt A, Wagner B
TI - Immunoferritin studies on the multiplication of Sindbis virus in chick embryo fibroblasts.
SO - Zentralbl Bakteriol [Orig A] 1977 Apr;237(4):444-52
AB - Replication of Sindbis virus chick embryo fibroblasts was studied by means of the immunoferritin technique. Virus specific antigens, diffusely distributed in the cytoplasm, were observed at first 3 hours p.i. At the same time in ohter cells ferritin particles in linear arrangement occured at the surface of vesicles. At these places heavily labelled nucleocapsids were observed later on. This means, that the surface of vesicles is a site of assembly of nucleocapsids. Maturation of virus takes place at the cell surface as well as at the vesicles by budding. In early stages of replication maturation at the membrane prevalis.

AU - Krag SS, Robbins PW
TI - Sindbis envelope proteins as endogenous acceptors in reactions of guanosine diphosphate-[14C]Mannose with preparations of infected chicken embryo fibroblasts.
SO - J Biol Chem 1977 Apr 25;252(8):2621-9
AB - Preparations of Sindbis-infected chicken embryo fibroblasts incubated with GDP-[14C]mannose and UDP-N-acetylglucosamine catalyze the glycosylation of endogenous phospholipids and membrane-associated proteins. The proteins are identified as the viral envelope proteins by precipitation with anti-Sindbis antiserum, by comparison with authentic virion glycoproteins on sodium dodecyl sulfate-poly-acrylamide gel electrophoresis, and by comparison of the glycopeptides of the membrane-associated glycoproteins with the glycopeptides from Sindbis virions on gel filtration chromatography. Our results indicate that glycophospholipid participates in the mannosylation of the viral proteins since an inhibitor of oligosaccharide-lipid synthesis also inhibits the labeling of the glycoproteins.

AU - Bracha M, Sagher D, Schlesinger MJ
TI - Reaction of the protease inhibitor p-nitrophenyl-p'-guanidinobenzoate with Sindbis virus.
SO - Virology 1977 Dec;83(2):246-53

AU - Leavitt R, Schlesinger S, Kornfeld S
TI - Impaired intracellular migration and altered solubility of nonglycosylated glycoproteins of vesicular stomatitis virus and Sindbis virus.
SO - J Biol Chem 1977 Dec 25;252(24):9018-23
AB - Tunicamycin, an antibiotic which prevents the glycosylation of newly synthesized proteins, inhibits the replication of both vesicular stomatitis virus and Sindbis virus. In tunicamycin-treated infected cells, all of the viral proteins are synthesized but the glycoproteins are devoid of carbohydrate. The nonglycosylated glycoproteins could not be detected on the outside of the plasma membrane by lactoperoxidase labeling, indirect immunofluorescence staining, or chymotrypsin treatment of intact cells, whereas the glycosylated glycoproteins were readily detected by all three methods. These results indicate that the bulk of the nonglycosylated glycoproteins are unable to undergo the normal migration to the cell surface. In contrast to the normal glycosylated viral glycoproteins, the nonglycosylated glycoproteins were insoluble in nonionic detergents such as Triton X-100. The nonglycosylated glycoprotein of vesicular stomatitis virus could be solubilized using a combination of 6 M guanidine hydrochloride and 0.2% Triton X-100, but precipitated when the 6 M guanidine was removed by dialysis. These results suggest that the lack of carbohydrate alters the properties of the glycoproteins, which may explain their impaired mobility through the intracellular membranous system.

AU - Wirth DF, Katz F, Small B, Lodish HF
TI - How a single Sindbis virus mRNA directs the synthesis of one soluble protein and two integral membrane glycoproteins.
SO - Cell 1977 Feb;10(2):253-63
AB - Previous work has shown that the 26S RNA found in Sindbis-infected chicken embryo fibroblasts encodes the three viral structural proteins, one internal protein, core, and two membrane glycoproteins, E1 and E2. This mRNA has one initiation site; core, E1, and E2 are derived by proteolytic cleavage. Here we show that during infection, the 26S RNA is found mainly in membrane-bound polysomes which synthesize all three virion structural proteins. These polysomes are released from the membrane upon treatment with puromycin and high salt. Newly synthesized core protein is localized on the cytoplasmic side of endoplasmic reticulum membranes, while newly synthesized envelope proteins are sequestered by the lipid bilayer. These results suggest that the nascent glycoproteins, presumably their amino termini, are of major importance in directing the binding of polysomes containing 26S mRNA to endoplasmic reticulum membranes and the subsequent transfer of glycoproteins into the bilayer.

AU - Jones KJ, Scupham RK, Pfeil JA, Wan K, Sagik BP, Bose HR
TI - Interaction of Sindbis virus glycoproteins during morphogenesis.
SO - J Virol 1977 Feb;21(2):778-87
AB - In cells infected with the Sindbis temperature-sensitive mutants ts-23 and ts-10 (complementation group D), which contain a defect in the envelope glycoprotein E1, the precursor polypeptide PE2 is not cleaved to the envelope glycoprotein E2 at the nonpermissive temperature. This defect is phenotypically identical to the defect observed in the complementation group E mutant, ts-20. The lesion in ts-23 is reversible upon shift to permissive temperature, whereas that of ts-10 is not. Antiserum against whole virus, E1, or E2 also prevents the cleavage of PE2 in cells infected with wild-type Sindbis virus. Because the cleavage of PE2 is inhibited by the lesion in mutants that are genotypically distinct and by anti-E1 or -E2 serum, it appears that PE2 and E1 exist as a complex in the membrane of the infected cell.

AU - Martire G, Bonatti S, ALIPERTI G, De Giuli C, Cancedda R
TI - Free and membrane-bound polyribosomes in BHK cells infected with Sindbis virus.
SO - J Virol 1977 Feb;21(2):610-8
AB - The data presented in the paper demonstrate that in BHK cells infected with Sindbis virus virtually all the 42S mRNA not in nucleocapsid is associated with free polyribosomes, whereas the 26S mRNA is distributed between free and membrane-bound polyribosomes. We suggest that the 26S RNA polyribosomes are bound to the membranes through the nascent chains of the B1 protein and that a large percentage of 26S RNA polyribosomes free in the cytoplasm may be due to the small amount of rough endoplasmic reticulum in BHK cells. In addition, we found that intracellular nucleocapsid is in the nonmembrane fraction of the cytoplasm of infected cells.

AU - Ueba N, Kimura T
TI - Polykaryocytosis induced by certain arboviruses in monolayers of BHK-21-528 cells.
SO - J Gen Virol 1977 Feb;34(2):369-73
AB - Multinucleated giant cell formation in a clone of BHK-21 cells, BHK-21-528, was tested with certain arboviruses. Eleven out of 19 viruses tested, Chikungunya, Getah, Sagiyama, Sindbis, Western equine encephalitis, St. Louis encephalitis, Japanese encephalitis, West Nile, Bunyamwera, Germiston and California encephalitis virus induced cell fusion after infection. All cases where giant cells were observed during the experiments, involved the B type cell fusion (fusion from within).

AU - Bell JW Jr, Waite MR
TI - Envelope antigens of Sindbis virus in cells infected with temperature-sensitive mutants.
SO - J Virol 1977 Feb;21(2):788-91
AB - Indirect fluorescent-antibody studies of living and fixed chick cells infected with temperature-sensitive mutants of Sindbis virus suggest that functional envelope glycoprotein E1 must be inserted through the plasma membrane before E2. PE2 and E2 do not affect the insertion of E1. The experiments also suggest that normal PE2, a glycosylated precursor to E2, reacts with anti-E2 serum; the abnormal PE2 made by a temperature-sensitive PE2 cleavage-defective mutant did not. Abnormal E1 proteins made by E1-defective mutants also failed to react with anti-E1 serum.

AU - Leavitt R, Schlesinger S, Kornfeld S
TI - Tunicamycin inhibits glycosylation and multiplication of Sindbis and vesicular stomatitis viruses.
SO - J Virol 1977 Jan;21(1):375-85
AB - Tunicamycin (TM), an antibiotic that inhibits the formation of N-acetylglucosamine-lipid intermediates, thereby preventing the glycosylation of newly synthesized glycoproteins, inhibits the growth of Sindbis virus and vesicular stomatitis virus in BHK cells. At 0.5 mug of TM per ml, the replication of both viruses is inhibited 99.9%. Noninfectious particles were not detected. All the viral proteins were synthesized in the presence of TM, but the glycoproteins were selectively altered in that they migrated faster than normal viral glycoproteins when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, suggesting defective glycosylation. Within 1 h after TM addition, [14C]glucosamine incorporation into glycoproteins was inhibited 20%, whereas [35S]methionine incorporation was unaffected. By 2 to 3 h after TM addition, glucosamine incorporation had fallen to 15% of control value, with methionine incorporation being 60% of normal. TM did not affect the growth of the nomenveloped encephalomyocarditis virus in BHK cells, demonstrating that TM is not a general inhibitor of protein synthesis. These data demonstrate that TM specifically inhibits the glycosylation of viral glycoproteins and that glycosylation may be essential for the normal assembly of enveloped viral particles.

AU - Mahnel H, Ottis K, Herlyn M
TI - [Stability in drinking and surface water of nine virus species from different genera (author's transl)]. [German]
SO - Zentralbl Bakteriol [Orig B] 1977 Jan;164(1-2):64-84
AB - The stability of nine viruses, Aujeszky, Sindbis, Vesicular Stomatitis, Newcastle Disease, Vaccinia, FMD, HCC, Reo and Teschen virus in drinking and surface water was investigated comparatively at temperatures of 9 and 15 degrees C as well as the influence of water factors like seasonal difference in temperature, pH value, hardness and sort of water. The results can be summarized as follows: 1. At temperatures of 9 to 15 degrees C the majority of the viruses remained stabil in natural water for an astonishing long time. 2. Starting with virus concentration of about 10(4) infectious units per ml Teschen, Vaccinia, Reo, HCC and ND virus could mostly be demonstrated in water longer than 200 days and FMD, Aujeszky, Vesicular Stomatitis and Sindbis virus for 20 to 50 days on average at 9 degrees C. The stability of the viruses investigated decreased in water in the named turn. 3. Based on these results it can be assumed that under natural conditions with very low virus content of some particles the labile viruses such as Toga, Herpes, Rhabdo and pH labile Picorna remain infectious in water for some days. They should not have any importance as water contaminants. More resistant viruses like Paramyxo may keep infectious for weeks and very stabile viruses such as Entero, Reo, Adeno and Pox viruses several weeks to months. 4. As to factors temperature, pH, hardness and sort of water-within the naturally differing range-only the temperature and only in the case of less resistant viruses showed significant influence on the virus stability in water.

AU - McCarthy M, Harrison SC
TI - Glycosidase susceptibility: a probe for the distribution of glycoprotein oligosaccharides in Sindbis virus.
SO - J Virol 1977 Jul;23(1):61-73
AB - Intact Sindbis virus and Triton-solubilized viral glycoprotein were treated with alpha-mannosidase and with a preparation of mixed glycosidases from Diplococcus pneumoniae to probe the accesibility of carbohydrate units on the viral surface. The products of glycosidase attack on Triton-solubilized virus showed that mose carbohydrate units of the glycoproteins are good substrates for these enzymes. The relative resistance of most of the viral oligosaccharides in intact virus particles showed that much of the carbohydrate is not accessible to glycosidases, probably because it is not exposed at the viral surface. The only completely accessible carbohydrate units on Sindbis glycoproteins were the type A oligosaccharides of E2. This differential accessibility of Sindbis oligosaccharides is discussed in relation to the organization of the viral surface.

AU - Smith JF, Brown DT
TI - Envelopments of Sindbis virus: synthesis and organization of proteins in cells infected with wild type and maturation-defective mutants.
SO - J Virol 1977 Jun;22(3):662-78

AU - Schupham RK, Jones KJ, Sagik BP, Bose HR Jr
TI - Virus-directed post-translational cleavage in Sindbus virus-infected cells.
SO - J Virol 1977 May;22(2):568-71
AB - The viral polypeptides synthesized in cells coinfected with group C and group D or E Sindbis virus mutants were studied. Cleavage of the ts2 protein occurs in cells coinfected with ts2 and ts20. Since the ts2 protein fails to chase in cells infected with ts2 alone, the activity effecting this cleavage must be, at least in part, virus specified.

AU - Strauss EG, Birdwell CR, Lenches EM, Staples SE, Strauss JH
TI - Mutants of Sindbis virus. II. Characterization of a maturation-defective mutant, ts103.
SO - Virology 1977 Oct 1;82(1):122-49

AU - Riedel B, Brown DT
TI - Role of extracellular virus on the maintenance of the persistent infection induced in Aedes albopictus (mosquito) cells by Sindbis virus.
SO - J Virol 1977 Sep;23(3):554-61
AB - Sindbis virus infection of cultured mosquito cells was found to have no effect on the growth of these cells; instead, a persistent infection of the culture followed an initial acute phase of rapid virus synthesis. Nearly all of the cells in the acute stage of infection were found to actively release virus in an infectious-center assay and to contain significant amounts of virus antigen as determined by immunofluorescence. Cells in the persistent phase of infection released few virions into the media, and only a small percentage of the cultured cells could be demonstrated to contain detectable amounts of virus antigen by immunofluorescence assay. In spite of the fact that nearly 100% of the cells in the persistent phase of infection were found to be virus negative by the two assays described above, the culture as a whole totally excluded the expression of superinfecting virus, as did cells in the acute phase, suggesting that most of the persistently infected cells did, indeed, contain virus information. Prevention of reinfection of the cells in the persistent phase by eliminating extracellular virus resulted in a curing of the culture such that it responded to infection by added virus much as would an uninfected culture.

AU - Symington J, Schlesinger MJ
TI - Characterization of a Sinbis virus variant with altered host range.
SO - Arch Virol 1978;58(2):127-36
AB - A variant of Sindbis virus which is much more infectious for mouse cells than the standard virus has been examined for biochemical properties which might be responsible for this biological difference. The variant has a much enhanced ability to adsorb to mouse plasmacytoma (MOPC 315) cells, but when these cells were pretreated with heparin, they were able to adsorb the standard virus almost as well as the variant. This suggested that there was a surface charge difference between variant and standard virus. Differential elution of the viruses from hydroxyapatite and the results of isoelectric focusing of the virion glycoproteins substantiate this interpretation. Both viral glycoproteins E1 and E2 from the variant were more negatively charged than those of the standard virus but we were unable to find changes in tryptic peptides of the variant. Differences were found in stability of the two virus strains to heat and proteolytic enzymes.

AU - Sefton BM
TI - The initial glycosylation of the Sindbis virus membrane proteins.
SO - Prog Clin Biol Res 1978;23:621-31
AB - The mechanism by which the membrane proteins of Sindbis virus are initially glycosylated during growth of the virus in chick cells was studied. The experiments suggest strongly that the 2 viral glycoproteins are glycosylated before release from the polysome and that this glycosylation involves transfer of a large, 1,800 dalton oligosaccharide to the polypeptide chains. The donor of the oligosaccharide is most probably a lipid.

AU - Bracha M, Schlesinger MJ
TI - Altered E2 glycoprotein of Sindbis virus and its use in complementation studies.
SO - J Virol 1978 Apr;26(1):126-35
AB - We have detected a Sindbis virus variant that contains a smaller-molecular-weight form of the viral glycoprotein E2. The molecular weight of the PE2 precursor and the glycosylation pattern of the smaller E2 are normal, thus indicating that this E2 is formed by an aberrant proteolytic cleavage. The altered E2 was detected in an RNA+ temperature-sensitive mutant that was defective in proteolytic cleavage, but the abnormal PE2-to-E2 reaction could be separated from the ts mutation and is not itself a temperature-sensitive defect. We used the variant E2 as a marker to monitor the complementation reaction between an RNA+ and an RNA- mutant and discovered that complementation was not reciprocal; the RNA defect was corrected by the RNA+ mutant gene products but the RNA+ defect was not complemented by any RNA- gene products. Other studies have shown that the smaller E2 is not preferentially selected during viral maturation and budding. No significant changes have been detected in the biological activity of virions with this altered E2 protein. Comparison of the electrophoretic migration of the E1 and E2 Sindbis viral glycoproteins in a two-dimensional polyacrylamide slab gel system that was first run in the absence of sulfhydryl-reducing reagent and then with beta-mercaptoethanol indicated that the mobility of E1, but not that of E2, was significantly altered by reduction.

AU - Peleg J, Pecht M
TI - Adaptation of an Aedes aegypti mosquito cell line to growth at 15 degrees C and its response to infection by Sindbis virus.
SO - J Gen Virol 1978 Feb;38(2):231-9
AB - Aedes aegypti mosquito cells, usually cultured at 28 to 30 degrees C, were adapted to grow at 15 degrees C. They were designated A. aegypti (c) cells, and had an estimated doubling time of 10 days. Sindbis virus (SV) replicated in these cells to peak titres of over 1.0 x 10(9) p.f.u./ml 8 to 10 days after inoculation. These, or about 10-fold lower titres, continued to be produced over a 130 day test period without causing visible cell damage. Continuous virus proliferation and the yield of uniformly large plaque forming progeny viruses are the two most important features which differentiate infection with this virus in A. aegypti (c) cells from that of A. aegypti cells grown at 28 degrees C (Peleg & Stollar, 1974). Absence of homologous interference vis-a-vis cell-virus coexistence suggests that homologous interference is not a prerequisite for maintaining cell-virus coexistence. Preinoculation of A. aegypti (c) cultures with a small plaque forming Sindbis virus (SV-S) leads, under certain conditions, to the establishment of homologous interference.

AU - Johnston RE, Faulkner P
TI - Reversible inhibition of Sindbis virus penetration in hypertonic medium.
SO - J Virol 1978 Jan;25(1):436-8
AB - Under hypertonic conditions, the penetration of baby hamster kidney cells by Sindbis virus was inhibited. Virus became cell associated, but remained susceptible to neutralization by specific antiserum and to removal by elution. When cells were returned to isotonicity, inhibition was reversed.

AU - Kolakofsky D, Altman S
TI - Endoribonuclease activity associated with animal RNA viruses.
SO - J Virol 1978 Jan;25(1):274-84
AB - A specific endoribonucleolytic activity was detected when detergent-lysed vesicular stomatitis of Sendai virus was incubated with the precursor to Escherichia coli tRNA Tyr. The cleavage products produced and the characteristics of the reaction were similar to those previously reported for human KB cell RNase NU. Like RNase NU, the virus-associated reaction generates 5'-hydroxyl and 3'-phosphate groups at the cleavage sites. At protein concentrations similar to those used to test vesicular stomatitis and Sendai viruses, virions of Sindbis virus and poliovirus also exhibited endoribonucleolytic activity, but reovirus, simian virus 40, and minute virus of mice did not. This endoribonuclease may be of physiological relevance to some of the viruses we tested.

AU - Pogodina VV, Medvedeva GS
TI - Interspecies interactions of arboviruses. III. Competition for virus envelope antigens in mixed Getah and Sindbis virus populations.
SO - Acta Virol 1978 Jul;22(4):270-7
AB - Interactions of Getah and Sindbis virus populations in mixed infections of 5 tissue systems were competitive or neutral. The type of interaction is regulated by the host cell and virus population density. On reproduction in mouse brains and SPEV cell cultures the mixed population exhibited antigenic markers of Getah virus; in Syrian hamster kidney and chick embryo cell cultures those of Sindbis virus; and in Chinese hamster kidney cell cultures the antigenic markers of both viruses. Mixed populations with monospecific antigenic characteristics contained genomes of both viruses detectable by the TC marker (dual spetrum of cytopathogenicity). Clonal analysis of such populations confirmed the occurrence of genome masking and demonstrated the formation of genotypically mixed particles. Possible mechanisms of the antigenic dominance of one virus and selective blocking of functions of the other virus are discussed.

AU - Bell JR, Hunkapiller MW, Hood LE, Strauss JH
TI - Amino-terminal sequence analysis of the structural proteins of Sindbis virus.
SO - Proc Natl Acad Sci U S A 1978 Jun;75(6):2722-6
AB - The structural proteins of Sindbis virus, an enveloped virus which belongs to the Togavirus family, have been subjected to automated Edman degradation using improved techniques. Extensive NH2-terminal sequences of about 50 residues were determined for each of the two membrane glycoproteins. In both cases the NH2 terminus of the molecule was found to be similar in composition to typical water-soluble proteins. The viral capsid protein was found to have a blocked alpha-amino group. This is consistent with other observations that viral proteins derived from the NH2 terminus of precursor molecules are often blocked.

AU - Brzeski H, Clegg JC, Atkins GJ, Kennedy SI
TI - Regulation of the synthesis of Sindbis virus-specified RNA: role of the virion core protein.
SO - J Gen Virol 1978 Mar;38(3):461-70
AB - Cells infected with seven different RNA+ mutants of Sindbis virus were found to accumulate a virus-specified polypeptide of mol. wt. 144000 (p144) during incubation at the non-permissive temperature, while at the same time synthesis of the virus structural proteins was drastically reduced. Mapping of the tryptic peptides of p144 showed that it contained the amino acid sequences of all the virus structural proteins. At the non-permissive temperature cells infected with the same seven mutants (out of 28 examined) also showed increased synthesis of 26S RNA, the mRNA for the virus structural proteins, relative to 42S RNA, and the virus genome, compared with infections by wild-type virus. We propose that both these phenotypic effects are the results of a single mutational step and that the primary defect in the processing of the virus structural protein precursor induces the relatively increased rate of synthesis of structural protein mRNA. Temperature-shift experiments with mutant-infected cells showed that p144 itself is not the agent of this effect. The failure of exposure to zinc ions to alter the RNA ratio in wild-type virus-infected cells suggested that the virus envelope proteins are not involved either, since their synthesis is preferentially inhibited under these circumstances. It is possible that it is the failure to synthesize the proper quantity of core protein in the mutant-infected cells which causes the shift of RNA synthesis in favour of structural protein mRNA.

AU - Bell JW Jr, Garry RF, Waite MR
TI - Effect of low-NaCl medium on the envelope glycoproteins of Sindbis virus.
SO - J Virol 1978 Mar;25(3):764-9
AB - Lowering the NaCl concentration of the medium inhibits the release of Sindbis virus from infected chicks cells at a stage after the nucleocapsids have bound to the membranes of the infected cells. The failure of trypsin treatment to release the inhibited virus and the ratio of the proteins in the inhibited cells make it seem likely that the inhibited virus is all intracellular. Experiments using antisera specific for E1 and E2, the envelope glycoproteins of Sindbis, suggest that the inhibitory effect of low-salt medium is mediated through an effect on E2. Lactoperoxidase radioiodination experiments indicate that, even when cleaved from PE2, E2 is not exposed on the surface of low-NaCl-treated chick cells.

AU - Fan DP, Sefton BM
TI - The entry into host cells of Sindbis virus, vesicular stomatitis virus and Sendai virus.
SO - Cell 1978 Nov;15(3):985-92
AB - We have compared the mechanisms of entry into host cells of three enveloped viruses: Sendai virus, vesicular stomatitis virus (VSV) and Sindbis virus. Virus entry by membrane fusion should antigenically modify the surface of a newly infected cell in such a way that it will be killed by anti-viral antibody and complement. On the other hand, virus entry by a mechanism involving uptake by the cell of the whole virion should not make cells sensitive to antibody and complement. As expected, cells newly infected with Sendai virus were readily and completely lysed by anti-Sendai antibody and complement. In marked contrast, however, cells newly infected with either Sindbis virus or VSV were killed by anti-viral antibody and complement only when infected at an extremely high multiplicity of infection, in excess of 1000 plaque-forming units per cell. We favor the following explanation for these results with Sindbis virus and VSV: a very large majority of the Sindbis and VSV virions entered the infected cells by some means other than membrane fusion, presumably engulfment of the whole particle. Efficient entry by way of membrane fusion may therefore not be a general characteristic of enveloped viruses.

AU - von Bonsdorff CH, Harrison SC
TI - Hexagonal glycoprotein arrays from Sindbis virus membranes.
SO - J Virol 1978 Nov;28(2):578-83
AB - Freeze-etch electron microscopy of Sindbis virus and of glycoprotein arrays derived from Sindbis membranes by nonionic detergent treatment shows that the local geometry of glycoprotein-glycoprotein interaction does not depend on the presence of the nucleocapsid.

AU - Strauss EG
TI - Mutants of Sindbis virus. III. Host polypeptides present in purified HR and ts103 virus particles.
SO - J Virol 1978 Nov;28(2):466-74
AB - The amounts of host-encoded protein present in purified Sindbis virions of both the HR strain and of a mutant (ts103) which makes multicored particles were examined. Cells were labeled with [35S]methionine before infection and with [3H]methionine postinfection. Virions were purified by velocity sedimentation and isopycnic banding, and their polypeptides were examined by polyacrylamide gels in a sodium dodecyl sulfate-containing discontinuous buffer system. Host prelabeled material was found principally in a small number of discrete polypeptides in HR virions, which contained as little as 0.2% host-encoded protein. Virus-sized particles of mutant ts103 contained significantly more host material, and multiploid particles from ts103 infection contained up to 12% host prelabeled protein.

AU - Feuer BI, Uzgiris EE, Deblois RW, Cluxton DH, Lenard J
TI - Length of glycoprotein spikes of vesicular stomatitis virus and Sindbis virus, measured in situ using quasi elastic light scattering and a resistive-pulse technique.
SO - Virology 1978 Oct 1;90(1):156-61

AU - Aliperti G, Schlesinger MJ
TI - Evidence for an autoprotease activity of sindbis virus capsid protein.
SO - Virology 1978 Oct 15;90(2):366-9

AU - Schlesinger S, Sly WS, Schulze IT
TI - Effects of neuraminidase of the phenotype of sindbis virus grown in fibroblasts obtained from patients with I-cell disease.
SO - Virology 1978 Sep;89(2):409-17

AU - Martin JH, Weir RC, Dalgarno L
TI - Replication of standard and defective Ross River virus in BHK cells: patterns of viral RNA and polypeptide synthesis.
SO - Arch Virol 1979;61(1-2):87-103
AB - Virus-specific macromolecule synthesis has been examined in BHK cells infected with Ross River virus. Unpassaged virus (R-0) and tenth-passage virus (R-10) have been compared. In infected cells R-0 generates i) 45S, 28S, 33S and 26S viral RNAs, ii) virus-specific precursor polypeptides of mol. wt. 127,000, 95,000 and 61,000 and iii) viral envelope proteins (mol. wts. 52,000 and 49,000) and nucleocapsid protein (mol. wt. 32,000). Thus in terms of virus-specific RNA and polypeptide synthesis, the replication of standard RRV is analogous to that of Semliki Forest virus and Sindbis virus. R-10 interferes with the replication of standard Ross River virus and generates large amounts of 19S and 24S defective RNA species; 45S and 26S RNA synthesis was not markedly affected. Defective RNAs are associated with RNAse-sensitive, 50S cytoplasmic particles which contain a variety of (mainly host) proteins but no nucleocapsid protein. No evidence for translation of defective RNAs was obtained. R-10 infection is also characterized by a relatively early shut down of host protein syntehsis and by a reduction in virus-specific polypeptide synthesis and nucleocapsid formation. The data suggest that defective Ross River virus interferes primarily at the translational level.

AU - Scupham RK, Sagik BP, Bose HR Jr
TI - The effect of membrane-active agents on Sindbis virus morphogenesis.
SO - Intervirology 1979;12(1):8-18
AB - In chicken cells infected by Sindbis virus and exposed to a variety of membrane-active compounds, virus release was inhibited. In infected cells exposed to antiserum directed against the virion glycoproteins E1 or E2, retinol, cortisone, Pb++ or insulin, the processing of two Sindbis virus precursor polypeptides which lead to the formation of virion polypeptides was inhibited. The B-protein, which is the precursor to both envelope proteins, accumulated in cells treated by these compounds. This precursor is generally not detected in chicken cells, presumably because it is processed rapidly. The cleavage of the precursor PE2 to the envelope glycoprotein E2 was also inhibited. E2 was also absent in cells exposed to menadione or to antiserum prepared against uninfected chicken cells. Since each of the compounds tested interfered with Sindbis virus polypeptide cleavage, despite their diverse mechanisms of action, it suggests that perturbation of normal membrane fluidity can interfere with Sindbis virus budding.

AU - Schmidt MF, Bracha M, Schlesinger MJ
TI - Evidence for covalent attachment of fatty acids to Sindbis virus glycoproteins.
SO - Proc Natl Acad Sci U S A 1979 Apr;76(4):1687-91
AB - Selective binding of lipid to glycoprotein was detected when [3H]palmitate-labeled Sindbis virus particles or viral-infected cells were disrupted by heating with sodium dodecyl sulfate, and glycoproteins were isolated by electrophoresis in sodium dodecyl sulfate/10% polyacrylamide gels. The smaller glycoprotein (E2) retained 2 to 3 times more labeled lipid than did the larger EI glycoprotein, and the cell-associated glycoprotein precursor (PE2) bound even less lipid. No lipid was associated with the nonglycosylated glycoproteins that accumulated in infected cells treated with tunicamycin. The labeled lipid remained bound to the glycoproteins after exhaustive extraction with chloroform/methanol of virus particles, infected-cell extracts, or isolated glycoproteins, but it could be extracted by chloroform/methanol after treating glycoproteins with mild alkali. Analysis by gas/liquid chromatography showed that 60% of the label was in palmitate and the balance of label was distributed between oleate and stearate. There were approximately 2 mol of fatty acid bound per mol of E1 glycoprotein. Proteolysis of the fatty acid-labeled glycoprotein with pepsin, thermolysin, and Pronase degraded the polypeptide to fragments that retained the fatty acids in an alkali-labile state. These data suggest that a covalent attachment of fatty acid may occur during maturation of the viral glycoproteins.

AU - Eaton BT
TI - Heterologous interference in Aedes albopictus cells infected with alphaviruses.
SO - J Virol 1979 Apr;30(1):45-55
AB - Maximum amounts of 42S and 26S single-stranded viral RNA and viral structural proteins were synthesized in Aedes albopictus cells at 24 h after Sindbis virus infection. Thereafter, viral RNA and protein syntheses were inhibited. By 3 days postinfection, only small quantities of 42S RNA and no detectable 26S RNA or structural proteins were synthesized in infected cells. Superinfection of A. albopictus cells 3 days after Sindbis virus infection with Sindbis, Semliki Forest, Una, or Chikungunya alphavirus did not lead to the synthesis of intracellular 26S viral RNA. In contrast, infection with snowshoe hare virus, a bunyavirus, induced the synthesis of snowshoe hare virus RNA in both A. Ablpictus cells 3 days after Sindbis virus infection and previously uninfected mosquito cells. These results suggested that at 3 days after infection with Sindbis virus, mosquito cells restricted the replication of both homologous and heterologous alphaviruses but remained susceptible to infection with a bunyavirus. In superinfection experiments the the alphaviruses were differentiated on the basis of plaque morphology and the electrophoretic mobility of their intracellular 26S viral RNA species. Thus, it was shown that within 1 h after infection with eigher Sindbis or Chikungunya virus, A. albopictus cells were resistant to superinfection with Sindbis, Chikungunya, Una, and Semliki Forest viruses. Infected cultures were resistant to superinfection with the homologous virus indefinitely, but maximum resistance to superinfection with heterologous alphaviruses lasted for approximately 8 days. After that time, infected cultures supported the replication of heterologous alphaviruses to the same extent as did persistently infected cultures established months previously. However, the titer of heterologous alphavirus produced after superinfection of persistently infected cultures was 10- to 50-fold less than that produced by an equal number of previously uninfected A. albopictus cells. Only a small proportion (8 to 10%) of the cells in a persistently infected culture was capable of supporting the replication of a heterologous alphavirus.

AU - Ng ML, Westaway EG
TI - Proteins specified by togaviruses in infected Aedes albopictus (Singh) mosquito cells.
SO - J Gen Virol 1979 Apr;43(1):91-101
AB - Yields of greater than 10(7) p.f.u./ml at 28 or 37 degrees C of the alphavirus Sindbis and the flavivirus Kunjin were obtained in the Aedes Albopictus (Singh) cell line, the latent periods being 4 to 6 and 10 to 12 h, respectively. Despite a high background of host protein synthesis, virtually all the virus-specified proteins of the flaviviruses Kunjin, Dengue-2 and Japanese encephalitis were labelled and resolved by slab gel electrophoresis of infected and uninfected cell proteins. In contrast, only one induced protein, of mol. wt. 30 000, was identified in cells labelled during Sindbis virus infection. The envelope glycoprotein V3 of Kunjin virus was resolved as a double band in samples of infected cytoplasm labelled with 3H-glucosamine, similar to that of carbohydrate-labelled V3 in vertebrate (Vero) cells. Attempts to reduce host protein synthesis selectively during labelling periods were unsuccessful using either a hypertonic inhibition block or treatment with 0.1 mu g actinomycin D per ml. The most efficient labelling of Kunjin virus-specified proteins was achieved at 37 degrees C in the presence of actinomycin D. The largest non-structural flavivirus protein NV5 migrated slightly faster than NV5 from infected vertebrate (Vero) cells. The small non-structural proteins NV1, NV1 1/2 and NV2 from infected mosquito cells were successively trimmed during post translational periods exceeding 70 min, compared to much shorter periods reported previously for post translational modifications of these proteins in vertebrate cells.

AU - Wirth DF, Lodish HF, Robbins PW
TI - Requirements for the insertion of the Sindbis envelope glycoproteins into the endoplasmic reticulum membrane.
SO - J Cell Biol 1979 Apr;81(1):154-62
AB - Previous work has shown that the Sindbis structural proteins, core, the internal protein, and PE2 and E1, the integral membrane glycoproteins are synthesized as a polyprotein from a 26S mRNA; core PE2 and E1 are derived by proteolytic cleavage of a nascent chain. Newly synthesized core protein remains on the cytoplasmic side of the endoplasmic reticulum while newly synthesized PE2 and E1 are inserted into the lipid bilayer, presumably via their amino-termini. PE2 and E1 are glycosylated as nascent chains. Here, we examine a temperature-sensitive mutant of Sindbis virus which fails to cleave the structural proteins, resulting in the production of a polyprotein of 130,000 mol wt in which the amino-termini of PE2 and E1 are internal to the protein. Although the envelope sequences are present in this protein, it is not inserted into the endoplasmic reticulum bilayer, but remains on the cytoplasmic side as does the core protein in cells infected with wild-type Sindbis virus. We have also examined the fate of PE2 and E1 in cells treated with tunicamycin, an inhibitor of glycosylation. Unglycosylated PE2 and E1 are inserted normally into the lipid bilayer as are the glycosylated proteins. These results are consistent with the notion that a specific amino-terminal sequence is required for the proper insertion of membrane proteins into the endoplasmic reticulum bilayer, but that glycosylation is not required for this insertion.

AU - Leone A, Shatkin AJ, Cancedda R
TI - Isolation of Sindbis virus 26 S RNA by cDNA-cellulose chromatography.
SO - FEBS Lett 1979 Apr 1;100(1):103-6

AU - Ben-Ze'ev A, Duerr A, Solomon F, Penman S
TI - The outer boundary of the cytoskeleton: a lamina derived from plasma membrane proteins.
SO - Cell 1979 Aug;17(4):859-65
AB - We prepared the cytoskeletal framework by gently extracting cells with Triton X-100. Lipids and soluble proteins were removed, leaving a complex meshlike structure which contains the cell nucleus and is composed of the major cell filament networks as well as the microtrabeculae with attached polyribosomes. The surface sheet or lamina covering this structure contains most of the cell surface proteins by the following criteria. Intact cells are labeled externally with radioiodine and then extracted with detergent. The iodinated poteins remain almost entirely with skeletal framework. A new major integral protein, the coat protein of Sindbis virus, is inserted into the plasma membrane of infected cells. This new protein is heavily iodinated and remains almost completely associated with the framework after extraction. Lectin binding and poliovirus binding sites are also retained after detergent extraction. Our results indicate that plasma membrane proteins form a sheet or lamina upon removal of lipids. This lamina reproduces even complex surface convolutions and appears to be supported by and intimately connected to the underlying skeleton. In this case, the surface lamina, and hence the plasma membrane of the original intact cell, might be viewed as a component of the cytoskeletal framework.

AU - Barrett PN, Atkins GJ
TI - Virulence of temperature-sensitive mutants of Sindbis virus in neonatal mice.
SO - Infect Immun 1979 Dec;26(3):848-52
AB - The virulence in neonatal mice of temperature-sensitive (ts) mutants of Sindbis virus was determined by measurements of mean survival time and 50% lethal dose after intracerebral injection. For 11 ts mutants, mean survival time was determined by the ribonucleic acid (RNA) phenotype, RNA+ mutants killing the mice sooner than RNA- mutants for the same titer of virus injected. Mortality caused by seven ts mutants was, with one exception, correlated with the proportion of revertants recovered after death. A82, a presumed double mutant showing low reversion, showed no detectable lethality. The pathogenicity of this mutant could be detected by inhibition of weight gain, which was proportional to the titer of virus injected. A low-level persistence, independent of the titer injected, occurred up to 7 days after injection. This was followed by complete clearance. It is concluded that the virulence of Sindbis virus may be considerably altered by mutation, and that this is related to events occurring at the cellular level.

AU - Lombard Y, Poindron P, Porte A
TI - [Origin and formation of different types of vacuoles induced by the multiplication of the alphavirus Sindbis virus in various cell systems]. [French]
SO - Can J Microbiol 1979 Dec;25(12):1452-9
AB - Spherule-containing vacuoles and nucleocapsid-bearing vacuoles (cytopathic vacuoles types 1 and 2 respectively of Grimley et al. 1968) induced by Alphavirus Sindbis were studied in brains from newborn mice, chicken embryo fibroblasts, and two lines of tumoral glial cells from muridae. Endoplasmic reticulum (ER) elements and finely granular electron-dense material also seen in contact with nucleocapsids seemed to be involved in the formation of the classical single-membrane spherule-containing vacuoles. A second type of spherule-containing vacuoles were characterized by their double membrane and an amorphous electron-dense content and were probably derived from mitochondria. Nucleocapsid-bearing vacuoles were formed from modified ER elements and seemed to be linked to excessive synthesis of viral material. Such ER alterations were not observed in RG6 cells. In these cells, there were only spherule-containing vacuoles, while nucleocapsids were seen associated with the cytoplasmic membrane only.

AU - Bonatti S, Blobel G
TI - Absence of a cleavable signal sequence in Sindbis virus glycoprotein PE2.
SO - J Biol Chem 1979 Dec 25;254(24):12261-4
AB - Partial NH2-terminal sequence analysis has been performed on some products that result from the translation of 26 S mRNA of Sindbis virus either in vivo or in vitro. In vivo products were obtained after pulse-labeling of virus-infected cells. In vitro products were obtained after cell-free translation either in the absence or presence of microsomal membrane vesicles from dog pancreas. The sequence data indicate that the selective translocation across the microsomal membrane required for a distinct portion of one of the integral viral envelope proteins (PE2) is not accompanied by cleavage of its putative signal sequence. Furthermore, the NH2-terminal sequence of a proteolytic derivative (PE'2) that contains the bulk of PE2 and that is generated after exposure of the microsomal vesicles to proteolytic enzymes is identical to that of intact PE2, strongly suggesting that only a COOH-terminal portion of PE2 is excluded from translocation across the microsomal membrane.

AU - Burke D, Keegstra K
TI - Carbohydrate structure of Sindbis virus glycoprotein E2 from virus grown in hamster and chicken cells.
SO - J Virol 1979 Feb;29(2):546-54

AU - Cancedda R, Shatkin AJ
TI - Ribosome-protected fragments from sindbis 42-S and 26-S RNAs.
SO - Eur J Biochem 1979 Feb 15;94(1):41-50
AB - Sindbis virus 42-S and 26-S RNAs labeled with 32P were purified from infected chick embryo fibroblasts. The RNA's were incubated in the presence of a wheat germ cell-free translating system under conditions that yielded 40-S and 80-S initiation complexes. After digestion with RNase A, ribosome-protected fragments were isolated by polyacrylamide gel electrophoresis and compared with respect to number, size, cap content and oligonucleotide composition. The two RNA species yielded several fragments of chain length about 35--40 nucleotides from 80S complexes and up to 60--65 nucleotides from 40-S complexes. The 5'-terminal capped sequence, m7 GpppA-U-G that is present in both Sindbis virus RNA's, was not retained in any of the ribosome-protected fragments. Fingerprint analyses indicated that the fragments derived from 40S and 80-S initiation complexes of each species of RNA were overlapping, but the fragments from 42-S and 26-S RNAs were unrelated. The complexity of the fingerprints were consistent with protection of a single, different initiation site in each Sindbis virus RNA.

AU - Sefton BM, Gaffney BJ
TI - Complete exchange of viral cholesterol.
SO - Biochemistry 1979 Feb 6;18(3):436-42
AB - The exchange of the cholesterol in the membranes of two enveloped viruses, Sindbis virus and vesicular stomatitis virus, with cholesterol present in lipid vesicles and in serum was measured. Biosynthetically labeled viral cholesterol underwent spontaneous and complete transfer to both lipid vesicles and to serum. The rate with which and the extent to which this process occurred were very similar for these two viruses. During incubation with lipid vesicles in excess, half of the viral cholesterol underwent transfer in approximately 4 h and more than 90% underwent transfer in 24h at 37 degrees C. Similar rates and extents of movement of viral cholesterol were observed when incubations were carried out with vesicles which contained cholesterol and phospholipid in the same molar ratio as in the virus or with egg lecithin vesicles which contained no cholesterol. When labeled cholesterol was present initially in the lipid vesicles, movement of cholesterol from the vesicles to the virus was observed. One implication of the fact that viral cholesterol undergoes extensive exchange with serum cholesterol is that cellular cholesterol is in equilibrium with that in the extracellular fluid.

AU - Bonatti S, Cancedda R, Blobel G
TI - Membrane biogenesis. In vitro cleavage, core glycosylation, and integration into microsomal membranes of sindbis virus glycoproteins.
SO - J Cell Biol 1979 Jan;80(1):219-24
AB - Sindbis virus 26S RNA has been translated in a cell-free protein-synthesizing system from rabbit reticulocytes. When the system was supplemented with EDTA-stripped dog pancreas microsomal membranes, the following results were obtained: (a) Complete translation of 26S RNA, resulting in the production, by endoproteolytic cleavage, of three polypeptides that are apparently identical to those forms of C, PE2, and E1 that are synthesized in vivo by infected host cells during a 3-min pulse with [35S]methionine. (b) Correct topological deposition of the three viral polypeptides--in vitro-synthesized PE2 and E1 forms are inserted into dog pancreas microsomal membranes in a orientation which, by the criterion of their limited (or total) inaccessibility to proteolytic probes, is indistinguishable from that of their counterparts in the rough endoplasmic recticulum of infected host cells; in vitro-synthesized C is not inserted into membranes and therefore is accessible to proteolytic enzymes, like its in vivo-synthesized counterpart. (c) Core glycosylation of in vitro-synthesized PE2 and E1 forms, as indicated by binding to concanavalin A Sepharose and subsequent elution by alpha-methylmannoside.

AU - Gottlieb C, Kornfeld S, Schlesinger S
TI - Restricted replication of two alphaviruses in ricin-resistant mouse L cells with altered glycosyltransferase activities.
SO - J Virol 1979 Jan;29(1):344-51
AB - Two mouse L cell variant lines (CL 3 and CL 6) selected for resistance to the toxic plant lectin ricin were restricted in their ability to replicate the two alphaviruses Sindbis virus and Semliki Forest virus. CL 3 cells have been shown to exhibit increased CMP-sialic acid:glycoprotein sialyltransferase and GM3 synthetase activities, whereas CL 6 cells have been shown to contain decreased UDPgalactose:glycoprotein galactosyltransferase and UDP-N-acetylglucosamine:glycoprotein N-acetylglucosaminyltransferase activities. The adsorption of Sindbis virus to CL 6 cells was considerably reduced, suggesting that the loss or inaccessibility of the receptors for Sindbis virus accounted for a major defect in virus production in these cells. In contrast, CL 3 synthesized Sindbis viral RNA and proteins but were unable to convert the precursor glycoprotein PE2 to the structural protein E2. The cleavage of PE2 to E2 was also blocked in both CL 3 and CL 6 cells infected with Semliki Forest virus.

AU - Vaananen P, Kaariainen L
TI - Haemolysis by two alphaviruses: Semliki Forest and Sindbis virus.
SO - J Gen Virol 1979 Jun;43(3):593-601
AB - Purified preparations of Semliki Forest (SFV) and Sindbis virus haemolyse red blood cells from several species of animals and birds. The optimal haemolysis by SFV was obtained at pH 5.8 with 1-day-old chick erythrocytes incubated at room temperature. Considerable variation in haemolytic activity was observed between different virus preparations purified by different methods. The haemolytic activity of SFV was inhibited by antisera against whole virus or isolated envelope proteins but not with antiserum against virus capsid protein. Neither lipid and detergent-free envelope protein octamers with high haemaggluinating titre, nor isolated nucleocapsids caused haemolysis. Fresh, unpurified SFV and Sindbis virus preparations did not haemolyse unless they were exposed for repeated cycles of freezing and thawing. It appears that the haemolytic activity resides in the virus glycoproteins(s) but can only be manifested in slightly damaged whole virus particles.

AU - Weitzman S, Grennon M, Keegstra K
TI - Comparison of Sindbis virus and immunoglobulin glycopeptides in mouse myeloma cells.
SO - J Biol Chem 1979 Jun 25;254(12):5377-82

AU - Welch WJ, Sefton BM
TI - Two small virus-specific polypeptides are produced during infection with Sindbis virus.
SO - J Virol 1979 Mar;29(3):1186-95
AB - We have identified and characterized two small virus-specific polypeptides which are produced during infection of cells with Sindbis virus, but which are not incorporated into the mature virion. The larger of these is a glycoprotein with an approximate molecular weight of 9,800 and is found predominantly in the medium of infected cells. Three independent lines of evidence demonstrate conclusively that this 9,800-dalton glycoprotein is produced during the proteolytic conversion of the precursor polypeptide, PE2, to the virion glycoprotein E2. This small glycoprotein is therefore analogous to the virion glycoprotein E3 of the very closely related alphavirus, Semliki Forest virus. The 9,800-dalton glycoprotein of Sindbis virus, unlike the E3 glycoprotein of Semliki Forest virus, is not, however, present in the viral particle. The other virus-specific polypeptide is 4,200 daltons in size, does not appear to be a glycoprotein, and is neither incorporated into the mature virus nor released into the culture medium. The gene for this small polypeptide is present in the viral 26S mRNA (the mRNA which encodes all the viral structural polypeptides) and appears to be located in the portion of the mRNA which encodes the two viral glycoproteins. The possibility that this 4,200-dalton polypeptide functions as a signal peptide during the synthesis of the viral membrane glycoproteins is discussed.

AU - Soderlund H, von Bonsdorff CH, Ulmanen I
TI - Comparison of the structural properties of Sindbis and Semliki forest virus nucleocapsids.
SO - J Gen Virol 1979 Oct;45(1):15-26
AB - The envelope spikes of Sindbis and Semliki Forest virus are arranged in a T = 4 icosahedral surface lattice and, by deduction, it has been suggested that the nucleocapsid proteins are similarly arranged. After treatment of the virions with a non-ionic detergent the released nucleocapsids sediment in sucrose gradients at about 160S and 150S and have densities in CsCl of 1.42 g/ml and 1.425 g/ml, respectively, for Sindbis and Semliki Forest virus. At pH 6.0 Sindbis nucleocapsids do not contract like those of Semliki Forest virus. Nucleocapsids of both viruses are sensitive to the action of ribonuclease but only those of Semliki Forest virus undergo a drastic structural rearrangement due to the treatment. EDTA treatment in hypotonic conditions results in a decrease in the S-value for both particles. Electron micrographs show that the SFV nucleocapsids are partly 'unfolded' while those of Sindbis appear slightly contracted after exposure to EDTA.

AU - Atkins GJ
TI - Establishment of persistent infection in BHK-21 cells by temperature-sensitive mutants of Sindbis virus.
SO - J Gen Virol 1979 Oct;45(1):201-7
AB - Twelve temperature-sensitive (ts) mutants of Sindbis were examined for their ability to establish persistent infection in BHK-21 cells at 39 degrees C. Five of these mutants were able to initiate colony formation in infected cultures, which followed an extensive c.p.e. Two of the mutants were able to establish persistent infections which survived beyond the fifth cell passage p.i. The ability to initiate colony formation was correlated with low reversion of the ts mutation, or with ability to interfer with the multiplication of the wild-type virus. Virus released from persistently infected cultures was not temperature-sensitive. The restriction of virus multiplication in persistently infected cells operated prior to virus-specified RNA synthesis. It is concluded that in this system establishment of persistent infection depends on an inhibition of virus multiplication early in infection and occurs in only a small proportion of infected cells.

AU - Dubin DT, Timko K, Gillies S, Stollar V
TI - The extreme 5'-terminal sequences of sindbis virus 26 and 42 S RNA.
SO - Virology 1979 Oct 15;98(1):131-41

AU - Bell JR, Strauss EG, Strauss JH
TI - Purification and amino acid compositions of the structural proteins of sindbis virus.
SO - Virology 1979 Sep;97(2):287-94

AU - Campadelli-Fiume G, Sinibaldi-Vallebona P, Cavrini V, Mannini-Palenzona A
TI - Selective inhibition of herpes simplex virus glycoprotein synthesis by a benz-amidinohydrazone derivative.
SO - Arch Virol 1980;66(3):179-91
AB - 1H-benz[f]indene-1.3(2H)dione-bis-amidinohydrazone (benzhydrazone) inhibited incorporation of 14C-glucosamine, 14C-fucose and 14C-mannose into glycoproteins of HEp-2 cells infected with various strains of herpes simplex virus 1 (HSV-1) and impaired RNA and protein synthesis to a low extent. These biochemical effects are very similar to those induced by glycosylation inhibitors such as tunicamycin, D-glucosamine and 2-deoxy-D-glucose. In contrast to these inhibitors, benzhydrazone reduced HSV glycoprotein synthesis selectively since it did not significantly modify i) the saccharide uptake into glycoproteins of uninfected and of Sindbis virus-infected cells, ii) viral growth and cell fusion in paramyxovirus-infected cells, two activities which depend on viral glycoprotein synthesis. Benzhydrazone had only minor effects on the overall metabolism of uninfected cells, since it did not alter cell growth rate, and amino acid, uridine, and hexose incorporations were about 80% those of untreated cells.

AU - Kohn A, Gitelman J, Inbar M
TI - Unsaturated free fatty acids inactivate animal enveloped viruses.
SO - Arch Virol 1980;66(4):301-7
AB - Unsaturated free fatty acids such as oleic, arachidonic or linoleic at concentrations of 5-25 microgram/ml inactivate enveloped viruses such as herpes, influenza, Sendai, Sindbis within minutes of contact. At these concentrations the fatty acids are inocuous to animal host cells in vitro. Naked viruses, such as polio, SV40 or EMC are not affected by these acids. Saturated stearic acid does not inactivate any viruses at concentrations tested. Though the mode of action of unsaturated fatty acids is not understood, electronmicrographs of enveloped viruses treated by them indicate that the inactivation is associated with disintegration of the virus envelope.

AU - Kalkkinen N, Jornvall H, Soderlund H, Kaariainen L
TI - Analysis of Semliki-Forest-virus structural proteins to illustrate polyprotein processing of alpha viruses.
SO - Eur J Biochem 1980;108(1):31-7
AB - The four structural proteins of Semliki Forest virus were purified in an amount of 30-50 nmol by preparative sodium dodecylsulfate/polyacrylamide gel electrophoresis. Each protein was subjected to N-terminal structural analysis by degradation in a liquid-phase sequencer. About 20 residues were determined for each of the two membrane glycoproteins E1 and E2. The amino acid sequence of E1 but not that of E2 showed extensive homology to the corresponding proteins of the closely related Sindbis virus. Both E1 and E2 seem to lack a signal sequence at the N terminus, since the proportion of polar amino acids in this region deviates from the proportion in the known hydrophobic signal sequences. The envelope glycoprotein E3 and the capsid protein did not yield any significant result on Edman degradation, suggesting that they have blocked N-terminal amino groups.

AU - Mastromarino P, Seganti L, Orsi N
TI - Relationship between enzymatic modifications of serum low density lipoproteins and their haemagglutination inhibiting activity towards Sindbis virus.
SO - Arch Virol 1980;65(1):37-44
AB - The chemical structure of human serum low density lipoproteins (LDL) involved in the inhibition of the haemagglutination by Sindbis virus was studied. Separation of lipoproteins into their protein and lipid components demonstrated that the inhibiting activity is almost completely due to the lipid moiety. The treatment of LDL and extracted lipoprotein lipids by phospholipase A2, C and D produced different effects and in particular a marked increase in the HI titre by the action of phospholipase A2. Moreover treatment with glycosidases significantly reduced the HI titre of LDL, thus suggesting the importance of carbohydrate moiety in the inhibiting lipoprotein molecule.

AU - Brinton MA, Plagemann PG
TI - Actinomycin D cytotoxicity for mouse peritoneal macrophages and effect on lactate dehydrogenase-elevating virus replication.
SO - Intervirology 1980;12(6):349-56
AB - Treatment of lactate dehydrogenase-elevating virus(LDV)-infected mouse peritoneal macrophage cultures with actinomycin D (1 microgram/ml) resulted in a progressive reduction in the formation of LDV-specific RNA and mature virus as the time of incubation with actinomycin D increased beyond 2-3 h. This effect, however, seemed to reflect an unusual sensitivity of macrophages to toxic effects of actinomycin D. Macrophage cytotoxicity and lysis became apparent 3-4 h after addition of actinomycin D; the initiation of synthesis of Sindbis virus RNA, which is insensitive to inhibition by actinomycin D in other cell culture systems, was also reduced in actinomycin-D-treated macrophages. Macrophages propagated in L-cell-conditioned medium were found to be less sensitive to actinomycin D cytotoxicity and, correspondingly, the initiation and synthesis of LDV RNA were less affected.

AU - Smith AL, Tignor GH
TI - Host cell receptors for two strains of Sindbis virus.
SO - Arch Virol 1980;66(1):11-26
AB - Experiments were performed to determine whether neuronal cells have different numbers of receptors for a neurovirulent and an avirulent strain of the same virus and whether neurotropic strains of different viruses share the same cellular receptors. Attempts were also made to characterize the receptors for the two strains of Sindbis virus on viable cells by studying their enzyme sensitivity. The number of cellular receptors available for Sindbis virus attachment to several cell lines was determined by saturation studies using two virus strains differing in their pathogenicity for adult mice. Cultured neuronal cells had 1.3 x 10(6) receptors for a neurovirulent strain (SaAr86) and only 5 x 10(4) for the avirulent prototype strain (EgAr339) of Sindbis virus. A refractory Lepidopteran cell type possessed 1 x 10(5) surface receptors for the neurovirulent variant while the average number of receptors on five permissive cell types was 1.5 x 10(6). Cellular receptors for the two strains of Sindbis virus on rat glioma cells were found to be distinct. The cellular receptors for EgAr339 on viable mammalian cells were sensitive to proteolytic cleavage, while those on living mosquito cells were insensitive to proteases, phospholipases and neuraminidase. The receptors for the neurovirulent variant on three mammalian cell types were less sensitive to enzymatic inactivation than those for the avirulent counterpart. After cleavage, the receptors for EgAr339 reappeared rapidly at 37 degrees and 4 degrees C, apparently in the absence of cellular synthesis.

AU - Oldstone MB, Tishon A, Dutko FJ, Kennedy SI, Holland JJ, Lampert PW
TI - Does the major histocompatibility complex serve as a specific receptor for Semliki Forest virus?.
SO - J Virol 1980 Apr;34(1):256-65
AB - Murine F9 and PCC4 teratoma cells do not express H-2 major transplantation antigens according to virus-specific T-lymphocyte cytotoxic or serological assays. However, such cells can be infected with and readily replicate many types of viruses (coxsackie B 3, mouse hepatitis, Sindbis, Semliki Forest [SFV], lymphocytic choriomeningitis, Pichinde, vesicular stomatitis, herpes simplex type 1) to the same extent as do murine F12 teratoma cells and mouse embryo fibroblasts, all of which express the H-2 determinants. In contrast, F9 and PCC4 cells are not productively infected with murine cytomegalovirus, whereas F12 and mouse embryo fibroblast cells are. In addition to replicating in H-2-negative murine teratoma cells, SFV replicates in H-2-negative murine lymphoblastoid cells. The ability of SFV to infect cells without H-2 antigens and then to effect viral antigenic expression in the cells' cytoplasm and on their surface with similar kinetics and in equivalent amounts as cells with H-2 antigens indicates that the H-2 receptor is not needed for SFV infection. Daudi cells, which lack HLA antigens, block the replication of SFV. This occurs at some point after receptor binding, as demonstrated by diminished viral mRNA. In addition, a possible membrane defect precludes viral exit in Daudi cells transfected with SFV infectious RNA. These results indicate that a cell's possession of H-2 antigens is not a requirement for SFV infection and that major histocompatibility complex antigens are not specific receptors for this virus.

AU - Schmidt MF, Schlesinger MJ
TI - Relation of fatty acid attachment to the translation and maturation of vesicular stomatitis and Sindbis virus membrane glycoproteins.
SO - J Biol Chem 1980 Apr 25;255(8):3334-9

AU - Strauss EG, Lenches EM, Stamreich-Martin MA
TI - Growth and release of several alphaviruses in chick and BHK cells.
SO - J Gen Virol 1980 Aug;49(2):297-307
AB - The growth and release of several alphaviruses, including several strains of Sindbis virus (the wild-type strain, the large plaque and small plaque variants of the HR strain, and the HR mutant ts103), Semliki Forest virus(SFV) and Middelburg virus, and of the unrelated rhabdovirus, vesicular stomatitis virus (VSV), have been compared in chick cells and in BHK-21 cells as a function of the culture conditions for the host cell and the ionic strength of the medium. The small plaque strain of Sindbis HR, as well as SFV, grew better in BHK cells, whereas the large plaque strain of Sindbis HR showed a preference for chick cells. Wild-type Sindbis and VSV grew equally well in either cell. The optimum ionic strength for virus production as well as inhibition of virus release into the medium at low ionic strength depended upon both the virus and the host cell. Thus, VSV grown in medium of low ionic strength gave no additional release of virus on incubation with hypertonic medium (minimum effect), whereas ts103 released very little virus without exposure to hypertonic conditions (maximum effect). The viruses could be ordered as follows: minimum effect = vesicular stomatitis virus < Middelburg virus < Semliki Forest virus < Sindbis wt < Sindbis HR (large plaque) < Sindbis HR (small plaque) < Sindbis ts103 = maximum effect. After several passages in culture, chick cells required hypertonic conditions for optimum production and release of Sindbis virus. Furthermore, BHK cells cultured in different media responded differently to ionic strength for virus production and release. These results suggest that there is a charge-dependent stop in the maturation of alpha-viruses, possibly a configurational rearrangement of glycoprotein E2 upon its formation from the precursor PE2, which is sensitive to the ionic strength of the medium, to the composition of the host plasmalemma and to differences in the virus glycoproteins.

AU - Fuller FJ, Marcus PI
TI - Sindbis virus. I. Gene order of translation in vivo.
SO - Virology 1980 Dec;107(2):441-51

AU - Erwin C, Brown DT
TI - Intracellular distribution of Sindbis virus membrane proteins in BHK-21 cells infected with wild-type virus and maturation-defective mutants.
SO - J Virol 1980 Dec;36(3):775-86
AB - The association of Sindbis virus proteins with cellular membranes during virus maturation was examined by utilizing a technique for fractionating the membranes of BHK-21 cells into three subcellular classes, which were enriched for rough endoplasmic reticulum, smooth endoplasmic reticulum, and plasma membrane. Pulse-chase experiments with wild-type (strain SVHR) virus-infected cells showed that virus envelope proteins were incorporated initially into membranes of the rough endoplasmic reticulum and subsequently migrated to the smooth and plasma membrane fractions. Large amounts of capsid protein were associated with the plasma membrane fraction even at the earliest times postpulse, and relatively little was found associated with the other membranes, suggesting a rapid and preferential association of nucleocapsids with the plasma membrane. We also examined the intracellular processing of the proteins of two temperature-sensitive Sindbis virus mutants in pulse-chase experiments at the nonpermissive temperature. Labeled virus proteins of mutant ts-20 (complementation group E) first appeared in the rough endoplasmic reticulum and were then transported to the smooth and plasma membrane fractions, as in wild-type (strain SVHR) virus-infected cells. In cells infected with ts-23 (complementation group D), the pulse-labeled virus proteins appeared initially in the rough membrane fraction and were transported to the smooth membrane fraction, but only limited amounts reached the plasma membrane. Thus, in ts-23-infected cells, the transport of the virus-encoded proteins from the smooth membranes seemed to be defective. In both ts-20- and ts-23-infected cells the envelope precursor polypeptide PE2 was not processed to E2, and no label was incorporated into free virus at the nonpermissive temperature.

AU - Scheefers H, Scheefers-Borchel U, Edwards J, Brown DT
TI - Distribution of virus structural proteins and protein-protein interactions in plasma membrane of baby hamster kidney cells infected with Sindbis or vesicular stomatitis virus.
SO - Proc Natl Acad Sci U S A 1980 Dec;77(12):7277-81
AB - The plasma membrane of baby hamster kidney (BHK-21) cells infected with either Sindbis or vesicular stomatitis virus was isolated by a technique involving the ingestion of latex beads by the cells. Plasma membrane isolated from Sindbis virus-infected cells contained only one (E1) of the three (E1, E2, and C) structural proteins of this virus. When the latex beads were pretreated with either polylysine or DEAE-dextran, plasma membrane obtained from Sindbis virus-infected cells contained all three structural proteins and PE2, a precursor to one of the structural proteins. In pulse-chase radiolabeling experiments with Sindbis virus-infected cells, it was possible to follow the appearance of the precursor protein (PE2) i the plasma membrane and its eventual conversion to E2. The appearance of Sindbis virus membrane proteins PE2 and E1 in the purified plasma membrane was not affected by the drug tunicamycin, an inhibitor of glycosylation. These experiments imply the following: (i) Cleavage of the Sindbis virus precursor polypeptide PE2 to E2 is not a prerequisite for its transport to the cell plasma membrane; (ii) transport of virus membrane proteins to the cell surface does not depend on glycosylation; and (iii) although all Sindbis virus structural proteins are associated with the plasma membrane, a generally accepted pairing of PE2-E1 or E2-E1 in the plasma membrane either does not exist or, if it does exist, involves a very weak interaction. The procedures used in this study also resulted in the successful isolation of plasma membrane from vesicular stomatitis virus-infected cells containing the glycoprotein, the matrix protein, and the nucleocapsid protein, a result that suggests that these proteins are located on the media side of baby hamster kidney cells grown in monolayer.

AU - Bonatti S, Sonenberg N, Shatkin AJ, Cancedda R
TI - Restricted initiation of protein synthesis on the potentially polycistronic Sindbis virus 42 S RNA.
SO - J Biol Chem 1980 Dec 10;255(23):11473-7
AB - Sindbis 42 S genome RNA was isolated from virions and translated in vitro before and after purification by oligo(dT)-cellulose chromatography and sucrose density gradient centrifugation under denaturing conditions. In intact 42 S RNA, only the 5'-proximal initiation site for the synthesis of nonstructural proteins was used. The internally located start site for viral structural protein formation was active in broken genome RNA molecules where, as a consequence of fragmentation, it was closer to a 5' end. The results of several kinds of experiments indicate that the fragmentation-dependent synthesis of structural proteins directed by virion RNA was not due to the presence of 26 S subgenomic messenger RNA.

AU - Vaananen P, Kaariainen L
TI - Fusion and haemolysis of erythrocytes caused by three togaviruses: Semliki Forest, Sindbis and rubella.
SO - J Gen Virol 1980 Feb;46(2):467-75
AB - Semliki Forest, Sindbis and rubella viruses can fuse erythrocytes from several different species. Large fusion vesicles consisting of tens to hundreds of red blood cells were seen under optical conditions. For the haemagglutination and cell fusion to occur the adsorption of virus and further incubation had to be carried out at pH 5.8. Haemagglutination took place over a wide temperature range (0 to 40 degrees C) whereas fusion required temperatures between 37 and 42 degrees C. Haemolysis of red blood cells induced by togaviruses also required initial incubation at pH 5.8 to enable attachment of the virus to occur after which the pH of the buffer could be raised to neutrality without inhibiting the haemolysis. The amount of togaviruses and Sendai virus required to fuse red blood cells was about the same [I haemagglutinating unit (HAU)/ml] but different ionic conditions were required for fusion.

AU - Roehrig JT, Corser JA, Schlesinger MJ
TI - Isolation and characterization of hybrid cell lines producing monoclonal antibodies directed against the structural proteins of Sindbis virus.
SO - Virology 1980 Feb;101(1):41-9

AU - Welch WJ, Sefton BM
TI - Characterization of a small, nonstructural viral polypeptide present late during infection of BHK cells by Semliki Forest virus.
SO - J Virol 1980 Jan;33(1):230-7
AB - BHK cells, late in infection with Semliki Forest virus, were found to contain a small virus-specific polypeptide not found in the mature virion. This polypeptide had an apparent molecular weight of 6,000 and is referred to here as the 6K protein. No [2-3H]mannose was incorporated into 6K, and hence it does not appear to be a glycoprotein. This protein appears to be a primary translation product of the subgenomic 26S mRNA, which encodes the viral structural proteins. The genes encoding the viral structural proteins are arranged on the message in the order of 5'-C-E3-E2-E1-3'. We have found that the gene coding for 6K is located to the 3' side of the gene encoding E2. Subcellular fractionation of pulse-labeled cells infected with Semliki Forest virus demonstrated that 6K, like the viral glycoproteins p62 and E1, was present predominantly in the rough microsomal membrane fraction. 6K appears to be analogous, therefore, to the nonstructural 4.2K protein present in cells infected with Sindbis virus.

AU - Bonatti S, Cerasuolo A, Cancedda R, Borgese N, Meldolesi J
TI - Studies on the intracellular distribution of Sindbis messenger RNA in infected chick-embryo fibroblasts. 1. Presence of extrapolyribosomal 26-S RNA in the membrane fraction.
SO - Eur J Biochem 1980 Jan;103(1):53-64
AB - Four hours after infection with Sindbis virus, chick embryo fibroblasts were studied by electron microscopy and cell fractionation. Electron microscopy of infected and non-infected cells revealed that infection produced a disaggregation of polyribosomes into monomers. Apart from this observation most cells appeared well preserved, and no degranulation of the rough endoplasmic reticulum was visible. Analysis of postnuclear supernatants by sucrose density gradients showed that no change in the relative proportions of free and membrane-bound ribosomes was produced by infection. Approximately 30% of the ribosomes and 50% of the viral RNA were found to be associated with membranes. Of the membrane-associated viral RNA, 70% was recovered as 26-S RNA. Similar results were obtained with fibroblasts infected by the temperature-sensitive Sindbis mutant ts2, which is defective in the co-translational processing of the viral gene products at the nonpermissive temperature. Sucrose gradient analysis of membrane-bound polyribosomes solubilized by detergent indicated that as much as 50% of the membrane-associated viral 26-S RNA is not integrated into polyribosomes and that most of the ribosomes are present as monomers or ribosomal subunits. Treatment with puromycin of living cells or of isolated membrane fractions under a variety of ionic conditions revealed that the viral RNA-membrane linkage is insensitive to puromycin but sensitive to high concentrations of monovalent ions. The bulk of the membrane-bound ribosomes were detached by high salt and recovered as ribosomal subunits on sucrose gradients. These results are consistent with the idea that in chick embryo fibroblasts infected with Sindbis virus only a small percentage of the ribosomes are engaged in protein synthesis, and that the Sindbis messenger RNA may attach to endoplasmic reticulum membranes through a ribosome-independent, salt-sensitive link.

AU - Borgese N, Meldolesi J, Bonatti S, Cancedda R
TI - Studies on the intracellular distribution of Sindbis messenger RNA in infected chick embryo fibroblasts. 2. Non-parallel distribution of 26-S RNA and ribosomes within microsomal subfractions.
SO - Eur J Biochem 1980 Jan;103(1):65-73
AB - The submicrosomal distribution of membrane-associated viral 26-S RNA in chick embryo fibroblasts infected with Sindbis virus was studied. Infected chick embryo fibroblasts were homogenized in the presence of low amounts of EDTA and fractionated by differential centrifugation. Analysis of postmitochondrial supernatants by isopycnic flotation on continuous sucrose gradients showed that membrane-associated 26-S RNA and ribosomes were not distributed in parallel, with an enrichment in 26-S RNA in the light microsomal subfractions. This distribution could not be explained by adsorption artifacts. Analysis of the distribution of microsomal constituents on sucrose gradients after treatment with digitonin ruled out the possibility that the 26-S RNA might be associated with Golgi or plasma membranes. The attachment of viral RNAs to endoplasmic reticulum membranes is discussed in relation to its possible role in viral morphogenesis.

AU - Johnson DC, Schlesinger MJ
TI - Vesicular stomatitis virus and sindbis virus glycoprotein transport to the cell surface is inhibited by ionophores.
SO - Virology 1980 Jun;103(2):407-24

AU - Leone A, Colantuoni V, Pontarelli G, Cancedda R
TI - Defective mutant of Sindbis virus with a smaller-molecular-weight form of the E1 glycoprotein.
SO - J Virol 1980 Jun;34(3):598-603
AB - We have isolated from a single plaque a mutant of Sindbis virus characterized by an E1 glycoprotein with higher electrophoretic mobility. This higher mobility is not attributable to a different extent of glycosylation of the protein nor to an altered proteolytic maturation pathway of the polypeptide precursor, but is the result of a deletion occurring during the replication of the viral RNA. The 26S RNA (the messenger for the Sindbis structural proteins) extracted from cells infected with the mutant is about 0.75 x 10(5) daltons smaller than the 26S RNA from the parental strain. As a consequence, in cells infected with the mutant, an E1 glycoprotein is synthesized with a polypeptide chain about 70 amino acids shorter. The biological relevance of this naturally occurring deletion of the viral genome is discussed.

AU - Duda E, Berencsi K
TI - Sindbis virus receptor protein of BHK cells.
SO - Acta Virol 1980 Mar;24(2):149-52
AB - Exposure of cultured BHK 21 cells to very low concentrations of non-ionic detergent Nonidet P40 resulted in the elution of cellular proteins located on the outer surface of the plasma membrane. One of these proteins, partially purified by affinity ultrafiltration and cosedimentation with Sindbis virions, seems to be the "receptor molecule" of Sindbis virus.

AU