title: Effect of vesicular stomatitis virus matrix protein on transcription directed by host RNA polymerases I, II, and III.
abstract: The matrix (M) protein of vesicular stomatitis virus (VSV) functions in virus assembly and inhibits host-directed gene expression independently of other viral components. Experiments in this study were carried out to determine the ability of M protein to inhibit transcription directed by each of the three host RNA polymerases (RNA polymerase I [RNAPI], RNAPII, and RNAPIII). The effects of wild-type (wt) VSV, v6 (a VSV mutant isolated from persistently infected cells), and tsO82 viruses on poly(A)+ and poly(A)- RNA synthesis were measured by incorporation of [3H]uridine. v6 and tsO82 viruses, which contain M-gene mutations, had a decreased ability to inhibit synthesis of both poly(A)+ and poly(A)- RNA. Nuclear runoff analysis showed that VSV inhibited transcription of 18S rRNA and alpha-tubulin genes, which was dependent on RNAPI and RNAPII, respectively, but infection with wt virus enhanced transcription of 5S rRNA by RNAPIII. The effect of M protein alone on transcription by RNAPI-, RNAPII-, and RNAPIII-dependent promoters was measured by cotransfection assays. M protein inhibited transcription from RNAPI- and RNAPII-dependent promoters in the absence of other viral gene products. RNAPIII-dependent transcription of the adenovirus VA promoters was also inhibited by M protein. However, as observed during wt VSV infection, M protein enhanced endogenous 5S rRNA transcription, indicating that the inhibition of transcription by RNAPIII was dependent on the nature of the promoter.
authors.affiliation: Department of Microbiology and Immunology, Wake Forest University School of Medicine, Winston-Salem, North Carolina 27157, USA.
authors.forename: M
authors.initials: M
authors.lastname: Ahmed
authors.forename: D S
authors.initials: DS
authors.lastname: Lyles
mesh_terms: D000818:Animals; D002460:Cell Line; D006224:Cricetinae; D012321:DNA-Directed RNA Polymerases / Q000378:metabolism*; D012367:RNA, Viral / Q000096:biosynthesis; D014158:Transcription, Genetic; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics / Q000378:metabolism*; D014763:Viral Matrix Proteins / Q000378:metabolism*
chemical_list: C094460:M protein, Vesicular stomatitis virus; D012367:RNA, Viral; D014763:Viral Matrix Proteins; D012321:DNA-Directed RNA Polymerases