This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Schultz, A M Articles by Oroszlan, S Search for Related Content PubMed PubMed Citation Articles by Schultz, A M Articles by Oroszlan, S

 Previous Article  |  Next Article 

J Virol. 1979 April; 30(1): 255-266

Post-translational modification of Rauscher leukemia virus precursor polyproteins encoded by the gag gene.

ABSTRACT

Post-translational modifications of retrovirus gag gene-encoded polyproteins include proteolytic cleavage, phosphorylation, and glycosylation. To study the sequence of these events, we labeled JLS-V9 cells chronically infected with Rauscher murine leukemia virus in pulse-chase experiments with the radioactive precursors [35S]methionine, [14C]mannose, [3H]glucosamine, and [32P]phosphate. Newly synthesized gag polyproteins which incorporated label, and the modified products derived from them, were identified by immunoprecipitation of cell lysates with anti-p30 rabbit serum, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Pulse-chase experiments were carried out in the presence as well as in the absence of tunicamycin, an inhibitor of glycosylation. Among the three major polyproteins synthesized in the absence of tunicamycin, two were found to be glycosylated but not phosphorylated. These were designated gPr80gag and gP94gag. Both shared identical [35S]methionine peptides with Pr65gag and p30. Of the two nonglycosylated precursors, Pr65gag and Pr75gag, only Pr65gag was found to be detectably phosphorylated, and Pr75gag could be readily identified only when glycosylation was inhibited. On the basis of these results, a scheme for the post-translational modification of gag polyproteins is proposed. According to this scheme the gag gene-encoded polyproteins are processed from a common precursor, Pr75gag, by two divergent pathways: one leading through the intermediate Pr65gag to internal virion components via cleavage and phosphorylation and the other via tunicamycin-sensitive mannosylation to the intermediate gPr80gag, which is further glycosylated to yield cell surface polyprotein gP94gag.

This article has been cited by other articles:

• Low, A., Datta, S., Kuznetsov, Y., Jahid, S., Kothari, N., McPherson, A., Fan, H. (2007). Mutation in the Glycosylated Gag Protein of Murine Leukemia Virus Results in Reduced In Vivo Infectivity and a Novel Defect in Viral Budding or Release. J. Virol. 81: 3685-3692 [Abstract] [Full Text]  
• Kuznetsov, Y. G., Datta, S., Kothari, N. H., Greenwood, A., Fan, H., McPherson, A. (2002). Atomic Force Microscopy Investigation of Fibroblasts Infected with Wild-Type and Mutant Murine Leukemia Virus (MuLV). Biophys. J 83: 3665-3674 [Abstract] [Full Text]  
• Fujisawa, R., McAtee, F. J., Favara, C., Hayes, S. F., Portis, J. L. (2001). N-Terminal Cleavage Fragment of Glycosylated Gag Is Incorporated into Murine Oncornavirus Particles. J. Virol. 75: 11239-11243 [Abstract] [Full Text]  
• Fujisawa, R., McAtee, F. J., Wehrly, K., Portis, J. L. (1998). The Neuroinvasiveness of a Murine Retrovirus Is Influenced by a Dileucine-Containing Sequence in the Cytoplasmic Tail of Glycosylated Gag. J. Virol. 72: 5619-5625 [Abstract] [Full Text]  
• Weldon, R. A. Jr., Parker, W. B., Sakalian, M., Hunter, E. (1998). Type D Retrovirus Capsid Assembly and Release Are Active Events Requiring ATP. J. Virol. 72: 3098-3106 [Abstract] [Full Text]