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Sendai virus C protein physically associates with Stat1
Author(s) -
Takeuchi Kenji,
Komatsu Takayuki,
Yokoo Junko,
Kato Atsushi,
Shioda Tatsuo,
Nagai Yoshiyuki,
Gotoh Bin
Publication year - 2001
Publication title -
genes to cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.912
H-Index - 115
eISSN - 1365-2443
pISSN - 1356-9597
DOI - 10.1046/j.1365-2443.2001.00442.x
Subject(s) - stat1 , biology , sendai virus , stat protein , gene , interferon , microbiology and biotechnology , tyrosine phosphorylation , phosphorylation , virus , biochemistry , virology , stat3
Background The P/C gene of the Sendai virus (SeV), a member of the family Paramyxoviridae, encodes C protein, which plays a crucial role in counteracting the antiviral effect of interferon (IFN). The C protein blocks IFN signalling to prevent the activation of IFN stimulated genes. However, its underlying molecular mechanism remains to be defined .ResultsSignal transducer and activator of transcription 1 (Stat1) is a critical component of IFN‐α/β and IFN‐γ signalling. We found that both unphosphorylated Stat1 and tyrosine‐phosphorylated (pY) Stat1 were present in a form of aberrant high molecular weight complexes (HMWCs) of over 2 MDa in infected cell extracts under low‐salt conditions. Of recombinant vaccinia viruses carrying each SeV gene, only those expressing the C gene induced Stat1‐HMWC. SeV infected cell extracts further displayed an in vitro ability to convert the pY‐Stat1 homodimer to pY‐Stat1‐HMWC. This cell extract activity was not seen after removal of the C protein from the extracts. C protein was therefore involved in the formation of HMWCs. The HMWCs decomposed into smaller complexes in a high‐salt buffer, and under this stringent (high‐salt) condition, as well as a physiological (isotonic) condition, both unphosphorylated Stat1 and pY‐Stat1 were co‐precipitated with anti‐C antibody.ConclusionThe C protein physically associates with Stat1. This suggests that SeV C protein directly targets Stat1 for inhibitory control on the transcriptional activation of IFN stimulated genes.