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
| Autor: | Alexander McPherson, Shoibal Datta, Audrey Low, Hung Fan, Nayantara H. Kothari, Yurii G. Kuznetsov, Sohail Jahid |
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| Rok vydání: | 2007 |
| Předmět: |
Glycosylation
viruses Viral budding Immunology Gene Products gag Genome Viral Microscopy Atomic Force Virus Replication Polymerase Chain Reaction Microbiology Virus Cell Line Mice Virology Murine leukemia virus Animals Glycoproteins Gammaretrovirus Viral Structural Proteins Infectivity biology Structure and Assembly Wild type Sequence Analysis DNA Fibroblasts Group-specific antigen biology.organism_classification Molecular biology Leukemia Virus Murine Viral replication Codon Nonsense Insect Science Models Animal |
| Zdroj: | Low, A; Datta, S; Kuznetsov, Y; Jahid, S; Kothari, N; McPherson, A; et al.(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. Journal of Virology, 81(8), 3685-3692. doi: 10.1128/JVI.01538-06. UC Irvine: Retrieved from: http://www.escholarship.org/uc/item/94d4w7hk |
| ISSN: | 1098-5514 0022-538X |
| Popis: | All gammaretroviruses, including murine leukemia viruses (MuLVs), feline leukemia viruses, and gibbon-ape leukemia virus, encode an alternate, glycosylated form of Gag polyprotein (glyco-Gag or gPr80 gag ) in addition to the polyprotein precursor of the viral capsid proteins (Pr65 gag ). gPr80 gag is translated from an upstream in-frame CUG initiation codon, in contrast to the AUG codon used for Pr65 gag . The role of glyco-Gag in MuLV replication has been unclear, since gPr80 gag -negative Moloney MuLV (M-MuLV) mutants are replication competent in vitro and pathogenic in vivo. However, reversion to the wild type is frequently observed in vivo. In these experiments, in vivo inoculation of a gPr80 gag mutant, Ab-X-M-MuLV, showed substantially lower (2 log) initial infectivity in newborn NIH Swiss mice than that of wild-type virus, and revertants to the wild type could be detected by PCR cloning and DNA sequencing as early as 15 days postinfection. Atomic force microscopy of Ab-X-M-MuLV-infected producer cells or of the PA317 amphotropic MuLV-based vector packaging line (also gPr80 gag negative) revealed the presence of tube-like viral structures on the cell surface. In contrast, wild-type virus-infected cells showed the typical spherical, 145-nm particles observed previously. Expression of gPr80 gag in PA317 cells converted the tube-like structures to typical spherical particles. PA317 cells expressing gPr80 gag produced 5- to 10-fold more infectious vector or viral particles as well. Metabolic labeling studies indicated that this reflected enhanced virus particle release rather than increased viral protein synthesis. These results indicate that gPr80 gag is important for M-MuLV replication in vivo and in vitro and that the protein may be involved in a late step in viral budding or release. |
| Databáze: | OpenAIRE |
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