分类： 生物学 >> 生物物理学 提交时间： 2016-05-11
Gao, Shijuan
Li, Jiandong
Song, Liping
Sheng, Chunjie
Liu, Dong
Jiang, Wei
Chen, Shuai
Huang, Wenlin
Wu, Jiaoxiang
Yao, Chen
Chen, Huiming
Liu, Ran-Yi
Chen, Shuai
Huang, Wenlin
Huang, Wenlin
Teng, Yan
摘要： Influenza A viruses (IAVs) rely on host factors to support their life cycle, as viral proteins hijack or interact with cellular proteins to execute their functions. Identification and understanding of these factors would increase our knowledge of the molecular mechanisms manipulated by the viruses. In this study, we searched for novel binding partners of the influenza A virus NS2 protein, the nuclear export protein responsible for overcoming host range restriction, by a yeast two-hybrid screening assay and glutathione S-transferase-pulldown and coimmunoprecipitation assays and identified AIMP2, a potent tumor suppressor that usually functions to regulate protein stability, as one of the major NS2-binding candidates. We found that the presence of NS2 protected AIMP2 from ubiquitin-mediated degradation in NS2-transfected cells and AIMP2 functioned as a positive regulator of IAV replication. Interestingly, AIMP2 had no significant effect on NS2 but enhanced the stability of the matrix protein M1. Further, we provide evidence that AIMP2 recruitment switches the modification of M1 from ubiquitination to SUMOylation, which occurs on the same attachment site (K242) on M1 and thereby promotes M1-mediated viral ribonucleoprotein complex nuclear export to increase viral replication. Collectively, our results reveal a new mechanism of AIMP2 mediation of influenza virus replication. IMPORTANCE Although the ubiquitination of M1 during IAV infection has been observed, the precise modification site and the molecular consequences of this modification remain obscure. Here, we demonstrate for the first time that ubiquitin and SUMO compete for the same lysine (K242) on M1 and the interaction of NS2 with AIMP2 facilitates the switch of the M1 modification from ubiquitination to SUMOylation, thus increasing viral replication.
分类： 物理学 >> 普通物理:统计和量子力学,量子信息等 提交时间： 2017-05-02
Zhou, Y [Zhou, Yu][ 1,2 ]
Chen, GF [Chen, Guofei][ 1 ]
Wang, W [Wang, Wei][ 1 ]
Wei, LH [Wei, Lihong][ 1 ]
Zhang, QJ [Zhang, Qiuju][ 1 ]
Song, LP [Song, Liping][ 2 ]
Fang, XZ [Fang, Xingzhong][ 1 ]
摘要： Two series of poly(ester imide)s derived from bis(trimellitic acid anhydride) phenyl ester (TAHQ) and bis[(3,4- dicarboxylic anhydride) phenyl] terephthalate (PAHP), as well as poly(ether imide)s based on hydroquinone diphthalic anhydride (HQDPA), were synthesized with aromatic diamines via solution polycondensation. These polyimide films were transparent with an ultraviolet-visible absorption cut-off wavelength below 375 nm, and with tensile strengths of 42.0–83.8 MPa, tensile moduli of 2.5–4.7 GPa and elongations at break of 2.1–5.4%. Compared with the poly(ether imide)s, the poly(ester imide)s showed higher glass transition temperatures (Tg), lower water absorption (WA) and lower temperature of 5% weight loss (Td5%). Moreover, the poly(ester imide)s derived from PAHP with a low electron affinity of 2.04 eV by theoretical calculation achieved better transparency, lower WA and slightly lower Tg than the corresponding TAHQ- based poly(ester imide)s.
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