宿主膜联蛋白A2与伪狂犬病病毒US3蛋白互作及其对细胞凋亡的影响

US3蛋白激酶是伪狂犬病病毒（PRV）的一个重要毒力因子，研究显示US3参与了细胞骨架重排、病毒复制和传播、细胞凋亡和干扰素信号通路等多个生物学过程，鉴定新的和US3互作的宿主蛋白对于认识其生物学功能具有重要意义。本研究首先利用免疫共沉淀和pull-down技术验证了US3和宿主膜联蛋白A2（ANXA2）的相互作用；然后利用RNAi技术，通过荧光定量PCR、病毒滴度测定和免疫印迹分析，发现敲低ANXA2的表达显著抑制了PRV在PK-15细胞上的增殖；进一步发现过表达ANXA2可以抑制PRV或者凋亡刺激剂诱导的细胞凋亡，提示ANXA2具有负调控细胞凋亡的作用。本研究进一步完善了可以和US3蛋白互作的宿主蛋白成员，加深了人们对ANXA2生物学功能的理解。

Host Annexin A2 Interacts with US3 of PRV and Its Effects on Apoptosis

US3 protein kinase is a critical virulence factor of pseudorabies virus (PRV). It is involved in many biological process, including cytoskeletal rearrangement, viral replication and transmission, antagonist apoptosis and interferon induced anti-viral response. The identification of US3 substrates is directly connected to understanding US3 functions and mechanisms. Here, we confirmed a host protein annexin A2 (ANXA2) can interact with US3 by co-immunoprecipitation and pull-down assay. Knock down the expression of ANXA2 can significantly affect the PRV proliferation on PK-15 cells, which was verified through quantitative PCR, viral titer and immunoblot analysis. Furthermore, we found that ANXA2 could inhibit apoptosis of PK-15 cells indued by PRV infection and apoptotic stimulator, suggesting that ANXA2 negatively regulates apoptosis. This study expands the host protein members that interact with US3 and deepens our understanding of the biological functions of ANXA2.