title: Measles virus C protein suppresses gamma-activated factor formation and virus-induced cell growth arrest.
abstract: Measles virus (MeV) produces two accessory proteins, V and C, from the P gene. These accessory proteins have been reported to contribute to efficient virus proliferation through the modulation of host cell events. Our previous paper described that Vero cell-adapted strains of MeV led host cells to growth arrest through the upregulation of interferon regulatory factor 1 (IRF-1), and wild strains did not. In the present study, we found that C protein expression levels varied among MeV strains in infected SiHa cells. C protein levels were inversely correlated with IRF-1 expression levels and with cell growth arrest. Forced expression of C protein released cells from growth arrest. C-deficient recombinant virus efficiently upregulated IRF-1 and caused growth arrest more efficiently than the wild-type virus. C protein preferentially bound to phosphorylated STAT1 and suppressed STAT1 dimer formation. We conclude that MeV C protein suppresses IFN-γ signaling pathway via inhibition of phosphorylated STAT1 dimerization.
authors.affiliation: Department of Microbiology, Sapporo Medical University School of Medicine, Chuo-ku, Sapporo 060–8556, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Yokota
authors.forename: Tamaki
authors.initials: T
authors.lastname: Okabayashi
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Fujii
mesh_terms: D002460:Cell Line; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000378:metabolism*; D007371:Interferon-gamma / Q000378:metabolism; D008459:Measles virus / Q000472:pathogenicity*; D011485:Protein Binding; D055503:Protein Multimerization; D050794:STAT1 Transcription Factor / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D014764:Viral Proteins / Q000378:metabolism*; D037521:Virulence Factors / Q000378:metabolism*
chemical_list: D050856:Interferon Regulatory Factor-1; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D014764:Viral Proteins; D037521:Virulence Factors; D007371:Interferon-gamma