61.
Foamy Virus Particle Formation
- Fischer, Nicole; Heinkelein, Martin; Lindemann, Dirk; Enssle, Jörg; Baum, Christopher; Werder, Evelyn; Zentgraf, Hanswalter; Müller, Justus G.; Rethwilm, Axel
Subgenomic expression plasmids for the so-called human foamy virus (HFV) structural gag, gag/pol, and env genes were constructed and used to analyze foamy virus particle formation by electron microscopy. Expression of an R-U5-gag-pol construct under control of the human cytomegalovirus immediate-early enhancer-promoter resulted in the formation of viral cores with a homogeneous size of approximately 50 nm located in the cytoplasm. Upon coexpression of an envelope construct, particles were observed budding into cytoplasmic vesicles and from the plasma membrane. Expression of the Gag protein precursor pr74 alone led to aberrantly formed viral particles of heterogeneous size and with open cores....
62.
Foamy Virus Particle Formation
- Fischer, Nicole; Heinkelein, Martin; Lindemann, Dirk; Enssle, Jörg; Baum, Christopher; Werder, Evelyn; Zentgraf, Hanswalter; Müller, Justus G.; Rethwilm, Axel
Subgenomic expression plasmids for the so-called human foamy virus (HFV) structural gag, gag/pol, and env genes were constructed and used to analyze foamy virus particle formation by electron microscopy. Expression of an R-U5-gag-pol construct under control of the human cytomegalovirus immediate-early enhancer-promoter resulted in the formation of viral cores with a homogeneous size of approximately 50 nm located in the cytoplasm. Upon coexpression of an envelope construct, particles were observed budding into cytoplasmic vesicles and from the plasma membrane. Expression of the Gag protein precursor pr74 alone led to aberrantly formed viral particles of heterogeneous size and with open cores....
63.
Molecular Genetic Study of the Interaction of Sindbis Virus E2 with Ross River Virus E1 for Virus Budding
- Yao, Jiansheng; Strauss, Ellen G.; Strauss, James H.
Glycoprotein PE2 of Sindbis virus will form a heterodimer with glycoprotein E1 of Ross River virus that is cleaved to an E2/E1 heterodimer and transported to the cell plasma membrane, but this chimeric heterodimer fails to interact with Sindbis virus nucleocapsids, and very little budding to produce mature virus occurs upon infection with chimeric viruses. We have isolated in both Sindbis virus E2 and in Ross River virus E1 a series of suppressing mutations that adapt these two proteins to one another and allow increased levels of chimeric virus production. Two adaptive E1 changes in an ectodomain immediately adjacent to...
64.
Molecular Genetic Study of the Interaction of Sindbis Virus E2 with Ross River Virus E1 for Virus Budding
- Yao, Jiansheng; Strauss, Ellen G.; Strauss, James H.
Glycoprotein PE2 of Sindbis virus will form a heterodimer with glycoprotein E1 of Ross River virus that is cleaved to an E2/E1 heterodimer and transported to the cell plasma membrane, but this chimeric heterodimer fails to interact with Sindbis virus nucleocapsids, and very little budding to produce mature virus occurs upon infection with chimeric viruses. We have isolated in both Sindbis virus E2 and in Ross River virus E1 a series of suppressing mutations that adapt these two proteins to one another and allow increased levels of chimeric virus production. Two adaptive E1 changes in an ectodomain immediately adjacent to...
65.
Polymerase Activity of Pichinde Virus
- Carter, Michael F.; Biswal, Nilambar; Rawls, William E.
Pichinde virus, a member of the arenavirus group, was examined for polymerase activity. Purified virus was found to contain RNA-dependent RNA polymerase but not RNA-dependent DNA polymerase activity. Since RNase but neither DNase nor actinomycin D inhibited the endogenous polymerase reaction, RNA of the virus appeared to be used as the template. The divalent cations Mg2+ and Mn2+ were required for optimal reactivity. The RNA product was partially resistant to RNase and the resistant portion had a sedimentation coefficient of 22 to 26S in sucrose gradients.
66.
Model for Vesicular Stomatitis Virus
- Cartwright, B.; Smale, C. J.; Brown, F.; Hull, R.
Vesicular stomatitis virus contains single-stranded ribonucleic acid of molecular weight 3.6 × 106 and three major proteins with molecular weights of 75 × 103, 57 × 103, and 32.5 × 103. The proteins have been shown to be subunits of the surface projections, ribonucleoprotein, and matrix protein, respectively. From these values and from estimates of the proportions of the individual proteins, it has been calculated that the virus has approximately 500 surface projections, 1,100 protein units on the ribonucleoprotein strand, and 1,600 matrix protein units. Possible models of the virus are proposed in which the proteins are interrelated.
67.
Structural Proteins of Pichinde Virus
- Ramos, Blanca A.; Courtney, Richard J.; Rawls, William E.
Pichinde virus, a member of the arenovirus group, was found to have four polypeptides by polyacrylamide gel electrophoresis. Two components, VI and VII, had molecular weights of about 72,000, whereas VIII had a molecular weight of 34,000. A minor component, VIV, had a molecular weight of about 12,000. Glucosamine was incorporated into VII and VIII, suggesting that these components were glycopeptides whereas VI and VIV were polypeptides. Treatment of the virus with Nonidet P-40 removed VIII, but VI and VII remained associated with the virus nucleic acid. This suggests a functional role of a ribonucleoprotein for VI and an envelope...
68.
Polymerase Activity of Pichinde Virus
- Carter, Michael F.; Biswal, Nilambar; Rawls, William E.
Pichinde virus, a member of the arenavirus group, was examined for polymerase activity. Purified virus was found to contain RNA-dependent RNA polymerase but not RNA-dependent DNA polymerase activity. Since RNase but neither DNase nor actinomycin D inhibited the endogenous polymerase reaction, RNA of the virus appeared to be used as the template. The divalent cations Mg2+ and Mn2+ were required for optimal reactivity. The RNA product was partially resistant to RNase and the resistant portion had a sedimentation coefficient of 22 to 26S in sucrose gradients.
69.
Model for Vesicular Stomatitis Virus
- Cartwright, B.; Smale, C. J.; Brown, F.; Hull, R.
Vesicular stomatitis virus contains single-stranded ribonucleic acid of molecular weight 3.6 × 106 and three major proteins with molecular weights of 75 × 103, 57 × 103, and 32.5 × 103. The proteins have been shown to be subunits of the surface projections, ribonucleoprotein, and matrix protein, respectively. From these values and from estimates of the proportions of the individual proteins, it has been calculated that the virus has approximately 500 surface projections, 1,100 protein units on the ribonucleoprotein strand, and 1,600 matrix protein units. Possible models of the virus are proposed in which the proteins are interrelated.
70.
Structural Proteins of Pichinde Virus
- Ramos, Blanca A.; Courtney, Richard J.; Rawls, William E.
Pichinde virus, a member of the arenovirus group, was found to have four polypeptides by polyacrylamide gel electrophoresis. Two components, VI and VII, had molecular weights of about 72,000, whereas VIII had a molecular weight of 34,000. A minor component, VIV, had a molecular weight of about 12,000. Glucosamine was incorporated into VII and VIII, suggesting that these components were glycopeptides whereas VI and VIV were polypeptides. Treatment of the virus with Nonidet P-40 removed VIII, but VI and VII remained associated with the virus nucleic acid. This suggests a functional role of a ribonucleoprotein for VI and an envelope...
71.
Fate of Sendai Virus Ribonucleoprotein in Virus-infected Cells
- Bukrinskaya, A. G.; Zhdanov, V. M.; Vorkunova, G. K.
The cytoplasmic extracts of Ehrlich ascites tumor cells infected with 32PO4 and 3H-leucine-labeled Sendai virus have been examined during the course of infection with respect to sedimentation behavior and buoyant densities of input virus radioactivity. It was found that 32P and 3H radioactivities were coincident, and, at 30 min after infection, the bulk of radioactivity was recovered in the polysome region of a sucrose gradient in the position of Sendai virus ribonucleoprotein (210S). The heterogeneity of radioactivity profiles appeared at 1 hr after infection and increased during 6 hr of incubation. The buoyant densities of input virus components were determined...
72.
Fate of Sendai Virus Ribonucleoprotein in Virus-infected Cells
- Bukrinskaya, A. G.; Zhdanov, V. M.; Vorkunova, G. K.
The cytoplasmic extracts of Ehrlich ascites tumor cells infected with 32PO4 and 3H-leucine-labeled Sendai virus have been examined during the course of infection with respect to sedimentation behavior and buoyant densities of input virus radioactivity. It was found that 32P and 3H radioactivities were coincident, and, at 30 min after infection, the bulk of radioactivity was recovered in the polysome region of a sucrose gradient in the position of Sendai virus ribonucleoprotein (210S). The heterogeneity of radioactivity profiles appeared at 1 hr after infection and increased during 6 hr of incubation. The buoyant densities of input virus components were determined...
73.
Induction of Cellular DNA Synthesis by the Nondefective Adenovirus 2-Simian Virus 40 Hybrid Viruses
- Schnipper, Lowell E.; Lewis, Andrew M.; Levine, Arthur S.
Induction of cellular DNA synthesis by the nondefective adenovirus 2-simian virus 40 hybrid viruses was examined in monkey and hamster cells. It was not possible to discriminate the effects of the hybrid viruses from those of wild-type adenovirus 2.
74.
Induction of Cellular DNA Synthesis by the Nondefective Adenovirus 2-Simian Virus 40 Hybrid Viruses
- Schnipper, Lowell E.; Lewis, Andrew M.; Levine, Arthur S.
Induction of cellular DNA synthesis by the nondefective adenovirus 2-simian virus 40 hybrid viruses was examined in monkey and hamster cells. It was not possible to discriminate the effects of the hybrid viruses from those of wild-type adenovirus 2.
75.
Identificación e incidencia de virus en pimiento en la zona centro norte de Chile y su asociación con vectores
- Sepúlveda R., Paulina; Larraín S., Patricia; Quiroz E., Carlos; Rebufel, P.; Graña, Fernando
Durante las temporadas de 2001-2002 y 2002-2003 se realizó una prospección de virus en pimientos (Capsicum annuum L.) en diversas localidades de la Región de Coquimbo (29,5-32° lat. Sur). La determinación de virus se realizó mediante la prueba DAS- ELISA. La importancia relativa de los virus encontrados para ambas temporadas fueron: Virus del mosaico del pepino (CMV) 23,3%; Virus del bronceado del tomate (TSWV) 20,8%; Virus del mosaico de la alfalfa (AMV) 14,8%;Virus Y de la papa (PVY) 14,5% e Impatients necrotic spot virus (INSV) 3,1% (primera identificación de este virus en pimiento en Chile); Virus del mosaico del tomate...
76.
Further Studies of a Simian Virus 40-Like Virus Isolated from Human Brain
- Weiner, L. P.; Herndon, R. M.; Narayan, O.; Johnson, R. T.
A virus similar to simian virus 40 was reisolated from brain homogenates of a patient with progressive multifocal leukoencephalopathy onto cultures of human fetal brain cells.
77.
Effect of Persistent Fibroma Virus Infection on Susceptibility of Cells to Other Viruses
- Padgett, Billie L.; Walker, Duard L.
Shope fibroma virus establishes a persistent cytoplasmic infection in primary (RK) and serially cultivated (DRK3) rabbit kidney cells which is accompanied by a morphological alteration of the cells. The response of such cells to superinfection by other viruses was compared with that of control cells by determining plaque production and virus yield of superinfecting viruses. It was found that the growth of other poxviruses, myxoma and vaccinia, was greatly inhibited in the fibroma virus-infected cells, but that of pseudorabies and herpes simplex viruses, which are unrelated deoxyribonucleic acid viruses, was virtually unaffected. The ribonucleic acid (RNA) viruses, poliovirus 1 and...
78.
Further Studies of a Simian Virus 40-Like Virus Isolated from Human Brain
- Weiner, L. P.; Herndon, R. M.; Narayan, O.; Johnson, R. T.
A virus similar to simian virus 40 was reisolated from brain homogenates of a patient with progressive multifocal leukoencephalopathy onto cultures of human fetal brain cells.
79.
Effect of Persistent Fibroma Virus Infection on Susceptibility of Cells to Other Viruses
- Padgett, Billie L.; Walker, Duard L.
Shope fibroma virus establishes a persistent cytoplasmic infection in primary (RK) and serially cultivated (DRK3) rabbit kidney cells which is accompanied by a morphological alteration of the cells. The response of such cells to superinfection by other viruses was compared with that of control cells by determining plaque production and virus yield of superinfecting viruses. It was found that the growth of other poxviruses, myxoma and vaccinia, was greatly inhibited in the fibroma virus-infected cells, but that of pseudorabies and herpes simplex viruses, which are unrelated deoxyribonucleic acid viruses, was virtually unaffected. The ribonucleic acid (RNA) viruses, poliovirus 1 and...
80.
Transformation of Murine Cells by Two Slow Viruses, Visna Virus and Progressive Pneumonia Virus
- Takemoto, Kenneth K.; Stone, Lawrence B.
Visna and progressive pneumonia virus (PPV), two antigenically related, non-oncogenic slow viruses which have ribonucleic acid (RNA)-dependent deoxyribonucleic acid (DNA) polymerase activity, were examined for their ability to transform cells. Murine cells which had been exposed to either visna or PPV developed foci of altered, spindle-shaped cells 3 to 4 weeks after infection. Visna and PPV transformed lines were established from these cultures. There was no evidence that other oncogenic DNA or RNA viruses were involved in the observed transformation. Visna or PPV could be rescued from all transformed lines by co-cultivation with normal sheep testis cells. Rescued virus was...
