主题: HIV-1 Nef hijacks clathrin coats by stabilizing AP-1:Arf1 polygons主讲人: 沈庆涛地点: 松江校区图文信息中心第一报告厅时间: 2017-09-16 09:30:00组织单位: 化学化工与生物工程学院
主讲人简介：沈庆涛，现任上海科技大学研究员，本研究组的主要研究方向是利用冷冻电子显微学作为主要技术手段研究蛋白与膜相互作用系统，并结合生物化学，荧光超分辨成像，X-射线晶体学以及分子动态模拟来深刻理解蛋白与膜相互作用的机制；同时，利用胞内系统进一步验证所得到的作用机制。在Science、Nature Protocols、Cell等刊发表了十多篇论文。
内容摘要：The lentiviruses HIV and simian immunodeficiency virus (SIV) subvert intracellular membrane traffic as part of their replication cycle. The lentiviral Nef protein helps viruses evade innate and adaptive immune defenses by hijacking the adaptor protein 1 (AP-1) and AP-2 clathrin adaptors. We found that HIV-1 Nef and the guanosine triphosphatase Arf1 induced trimerization and activation of AP-1. Here we report the cryo-electron microscopy structures of the Nef- and Arf1-bound AP-1 trimer in the active and inactive states. A central nucleus of three Arf1 molecules organizes the trimers. We combined the open trimer with a known dimer structure and thus predicted a hexagonal assembly with inner and outer faces that bind the membranes and clathrin, respectively. Hexagons were directly visualized and the model validated by reconstituting clathrin cage assembly. Arf1 and Nef thus play interconnected roles in allosteric activation, cargo recruitment, and coat assembly, revealing an unexpectedly intricate organization of the inner AP-1 layer of the clathrin coat.