Most retroviruses employ a frameshift mechanism during polyprotein synthesis to balance appropriate ratios of structural proteins and enzymes. To investigate the requirements for individual precursors in retrovirus assembly, we modified the polyprotein repertoire of Mason-Pfizer monkey virus (M-PMV) by mutating the frameshift sites to imitate the polyprotein organization of Rous sarcoma virus (Gag-Pro and Gag-Pro-Pol) or Human immunodeficiency virus (Gag and Gag-Pro-Pol). For the "Rous-like" virus, assembly was impaired with no incorporation of Gag-Pro-Pol into particles and for the "HIV-like" virus an altered morphogenesis was observed. A mutant expressing Gag and Gag-Pro polyproteins and lacking Gag-Pro-Pol assembled intracellular particles at a level similar to the wild-type. Gag-Pro-Pol polyprotein alone neither formed immature particles nor processed the precursor. All the mutants were non-infectious except the "HIV-like", which retained fractional infectivity.
- MeSH
- Simian Acquired Immunodeficiency Syndrome virology MeSH
- Chlorocebus aethiops MeSH
- COS Cells MeSH
- Financing, Organized MeSH
- Gene Products, gag genetics MeSH
- Gene Products, pol genetics MeSH
- Humans MeSH
- Mason-Pfizer monkey virus genetics pathogenicity MeSH
- RNA, Messenger genetics MeSH
- Frameshift Mutation MeSH
- Protein Biosynthesis MeSH
- RNA, Viral genetics MeSH
- Transfection MeSH
- Virion genetics pathogenicity MeSH
- Viral Proteins genetics MeSH
- Rous sarcoma virus genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
