Abstract

Quantitative separation of murine leukemia virus proteins by reversed-phase high-pressure liquid chromatography reveals newly described gag and env cleavage products. L E Henderson , R Sowder , T D Copeland , G Smythers and S Oroszlan ABSTRACT The structural proteins of murine type C retroviruses are proteolytic cleavage products of two different precursor polyproteins coded by the viral gag and env genes. To further investigate the nature and number of proteolytic cleavages involved in virus maturation, we quantitatively isolated the structural proteins of the Rauscher and Moloney strains of type C murine leukemia virus (R-MuLV and M-MuLV, respectively) by reversed-phase high-pressure liquid chromatography. Proteins and polypeptides isolated from R-MuLV included p10, p12, p15, p30, p15(E), gp69, and gp71 and three previously undescribed virus components designated here as p10', p2(E), and p2(E). Homologous proteins and polypeptides were isolated from M-MuLV. Complete or partial amino acid sequences of all the proteins listed above were either determined in this study or were available in previous reports from this laboratory. These data were compared with those from the translation of the M-MuLV proviral DNA sequence (Shinnick et al., Nature (London) 293:543-548, 1981) to determine the exact nature of proteolytic cleavages for all the structural proteins described above and to determine the origin of p10' and p2(E)s. The results showed that, during proteolytic processing of gp80env from M-MuLV (M-gp 80env), a single Arg residue was excised between gp70 and p15(E) and a single peptide bond was cleaved between p15(E) and p2(E). The structure of M-gPr80env is gp70-(Arg)-p15(E)-p2(E). The data suggest that proteolytic cleavage sites in R-gp85env are identical to corresponding cleavage sites in M-gp80env. The p2(E)s are shown to be different genetic variants of p2(E) present in the uncloned-virus preparations. The data for R- and M-p10's shows that they are cleavage products of the gag precursor with the structure p10-Thr-Leu-Asp-Asp-OH. The complete structure of Pr65gag is p15-p12-p30-p10'. Stoichiometries of the gag and env cleavage products in mature R- and M-MuLV were determined. In each virus, gag cleavage products (p15, p12, p30, and p10 plus p10') were found in equimolar amounts and p15(E)s were equimolar with p2(E)s. The stoichiometry of gag to env cleavage products was 4:1. These data are consistent with the proposal that proteolytic processing of precursor polyproteins occurs after virus assembly and that the C-terminal portion of Pr15(E) (i.e., p15(E)-p2(E)) is located on the inner side of the lipid bilayer of the virus. CiteULike Connotea Delicious Digg Facebook Google+ Mendeley Reddit StumbleUpon Twitter What's this? « Previous | Next Article » Table of Contents This Article J. Virol. November 1984 vol. 52 no. 2 492-500 » Abstract PDF Classifications Research Article Services Email this article to a colleague Similar articles in ASM journals Alert me when this article is cited Alert me if a correction is posted Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of JVI Download to citation manager Reprints and Permissions Copyright Information Books from ASM Press MicrobeWorld Citing Articles Load citing article information Citing articles via Web of Science Citing articles via Google Scholar Google Scholar Articles by Henderson, L. E. Articles by Oroszlan, S. Search for related content PubMed PubMed citation Articles by Henderson, L. E. Articles by Oroszlan, S. Related Content Load related web page information Social Bookmarking CiteULike Connotea Delicious Digg Facebook Google+ Mendeley Reddit StumbleUpon Twitter What's this? current issue January 2012, volume 86, issue 1 Spotlights in the Current Issue Two Xenotropic Murine Leukemia Virus Parents Breaking the Entry Targeting Barrier Complex Morphology and Dynamic Development of Poliovirus Membranous Replication Structures Revealed A Staining Artifact Explains Apparent Varicella-Zoster Virus Protein Expression in Neurons Recent Mumps Outbreaks Are Not Caused by Immune Escape Alert me to new issues of JVI About JVI Subscribers Authors Reviewers Advertisers Inquiries from the Press Permissions & Commercial Reprints ASM Journals Public Access Policy JVI RSS Feeds 1752 N Street N.W. • Washington DC 20036 202.737.3600 • 202.942.9355 fax • journals@asmusa.org Print ISSN: 0022-538X Online ISSN: 1098-5514 Copyright © 2011 by the American Society for Microbiology. For an alternate route to JVI .asm.org, visit: http://intl- JVI .asm.org | More Info» var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); var pageTracker = _gat._getTracker("UA-5821458-1"); pageTracker._trackPageview();