Sendai virus C protein impairs both phosphorylation and dephosphorylation processes of Stat1.
Sendai virus expresses C protein that blocks interferon (IFN) signaling. We previously reported suppression of IFN-stimulated tyrosine phosphorylation of signal transducers and activators of transcription (Stats) in infected cells. However this conclusion has remained controversial. To settle it, we re-examined the effect of C protein expression on phosphorylation of Stat1 in detail. IFN-stimulated tyrosine phosphorylation of Stat1 was doubtlessly suppressed early in infection, but the suppression was incomplete, suggesting the importance of the unknown blocking mechanism that inactivates the tyrosine-phosphorylated (pY)-Stat1 generated as the signaling leak. Interestingly, the dephosphorylation process of pY-Stat1 was also impaired. These effects on both phosphorylation and dephosphorylation processes were attributable to the function of the C protein.
Komatsu
Takayuki
T
Department of Microbiology, Fukui Medical University School of Medicine, Fukui 910-1193, Japan.
Takeuchi
Kenji
K
Yokoo
Junko
J
Gotoh
Bin
B
D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D016898:Interferon-alpha / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D010768:Phosphoserine / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D021381:Protein Transport; D050794:STAT1 Transcription Factor; D029082:Sendai virus; D019311:Staurosporine / Q000494:pharmacology; D015534:Trans-Activators / Q000378:metabolism*; D014764:Viral Proteins / Q000494:pharmacology*
D004268:DNA-Binding Proteins; D016898:Interferon-alpha; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D015534:Trans-Activators; D014764:Viral Proteins; C051221:nonstructural C protein, Sendai virus; D010768:Phosphoserine; D019000:Phosphotyrosine; D007371:Interferon-gamma; D019311:Staurosporine