Mao Hongxia, Chattopadhyay Santanu, Banerjee Amiya K
Virology Section, Department of Molecular Genetics, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, OH 44195, USA.
Gene Expr. 2010;15(1):43-50. doi: 10.3727/105221610x12819686555132.
Human parainfluenza virus type 3 (HPIV3), one of the paramyxoviruses, uses its accessory C protein as an antagonist against interferon (IFN)-mediated host innate immunity. We have previously shown that the C protein significantly decreased the IFN-induced phosphorylation of signal transducer and activator of transcription (Stat) 1 and the formation of gamma IFN activation factor (GAF) complex, thus abrogating the antiviral activity of the IFNs against vesicular stomatitis virus (VSV) replication. Here, by mutational analyses we demonstrated that the N-terminal truncation of the C protein (CNdelta25 and CNdelta50) substantially (approximately 50%) recovers the IFN-induced responses, suggesting the critical role of the N-terminal region of the C protein in IFN signaling. Furthermore, our results indicate that the charged amino acid residues within the N-terminal region of the C protein regulate the antagonistic effect of the C protein on IFN signaling.
人副流感病毒3型（HPIV3）是副粘病毒之一，利用其辅助C蛋白作为干扰素（IFN）介导的宿主固有免疫的拮抗剂。我们之前已经表明，C蛋白显著降低了IFN诱导的信号转导和转录激活因子（Stat）1的磷酸化以及γ干扰素激活因子（GAF）复合物的形成，从而消除了IFN对水疱性口炎病毒（VSV）复制的抗病毒活性。在此，通过突变分析我们证明，C蛋白的N端截短形式（CNdelta25和CNdelta50）能显著（约50%）恢复IFN诱导的反应，这表明C蛋白的N端区域在IFN信号传导中起关键作用。此外，我们的结果表明，C蛋白N端区域内的带电荷氨基酸残基调节C蛋白对IFN信号传导的拮抗作用。
