Dephosphorylation failure of tyrosine-phosphorylated STAT1 in IFN-stimulated Sendai virus C protein-expressing cells.
Sendai virus C protein (SeV C) has been reported to counteract the antiviral activities of interferons (IFNs) by inhibiting the expression of IFN-stimulated gene products. In SeV C-expressing cells, formation of an active ISGF3 complex and translocation of STAT1 into the nucleus were not observed. STAT1 was continuously phosphorylated at tyrosine 701 by IFN signaling; however, its serine phosphorylation was suppressed. In addition, tyrosine-phosphorylated STAT1 grew to form abnormally huge complexes. These findings suggest that the counteraction of IFN in SeV C-expressing cells is caused by disordered phosphorylation and dephosphorylation of STAT1.
Saito
Sakura
S
Department of Viral Diseases and Vaccine Control, National Institute of Infectious Diseases, 4-7-1 Gakuen, Musashimurayama, Tokyo 208-0011, Japan. sakura@nih.go.jp
Ogino
Toshio
T
Miyajima
Naoko
N
Kato
Atsushi
A
Kohase
Masayoshi
M
D004268:DNA-Binding Proteins / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D050832:Interferon-Stimulated Gene Factor 3; D050834:Interferon-Stimulated Gene Factor 3, gamma Subunit; D016898:Interferon-alpha / Q000494:pharmacology*; D010766:Phosphorylation / Q000187:drug effects; D019000:Phosphotyrosine / Q000378:metabolism; D050794:STAT1 Transcription Factor; D015398:Signal Transduction; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014764:Viral Proteins / Q000378:metabolism*
D004268:DNA-Binding Proteins; C494227:IRF9 protein, human; D050832:Interferon-Stimulated Gene Factor 3; D050834:Interferon-Stimulated Gene Factor 3, gamma Subunit; D016898:Interferon-alpha; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D015534:Trans-Activators; D014157:Transcription Factors; D014764:Viral Proteins; C051221:nonstructural C protein, Sendai virus; D019000:Phosphotyrosine