Arpin结合的Arp2/3复合物在调控细胞迁移过程中的冷冻电镜原位结构研究

肿瘤侵袭转移与细胞迁移行为紧密相关，而Arp2/3复合物是诱导新生微丝结合的重要成核元件，精确调控了细胞迁移过程。Arpin是Arp2/3复合物的重要调节因子，但是，它如何靶向结合Arp2/3复合物并控制细胞迁移行为的具体机制仍不为人知。目前冷冻电镜技术给生物大分子结构分析带来了革命性的进步，在细胞原位直接解析大分子复合体的三维结构已成为可能。在前期实验中，申请人已经通过晶体学的手段解析得到Arpin蛋白的高分辨率晶体结构。本项目将继续深入研究，利用冷冻光电关联成像技术、高分辨率冷冻电子断层数据收集和三维体数据精确均类等技术研究在细胞迁移过程中，Arpin结合Arp2/3复合体的原位结构，揭示Arpin蛋白发挥功能的分子机制。本项目的顺利开展，将阐明Arpin蛋白调节微丝生长的机理，同时为靶向抑制Arp2/3复合物来研发抗肿瘤转移药物提供新的思路和实验基础。

The invasion and metastasis of tumor cell is closely related to cell migration behavior. In molecular level, the cell migration is primarily the assembly and disassembly process of microfilament, which is composed of Actin. This process is accurately regulated by Arp2/3 complex, which forms the most important nucleation components to induce the formation of new-born microfilament. Arpin is a new regulator of Apr2/3 complex, which could not only slow down the cell migration but also control the migration direction. So far, there is no high resolution structure of Arpin or its complex structure with Arp2/3, so it is obscure why Arpin could interact with Arp2/3 to steer cell migration. In this proposal, we will solve the crystal structure of Arpin, and also solve the cryo-EM structure of complex formed by Arpin and Arp2/3. Together with biochemical and cell migration experiments, we will reveal the molecular mechanisms of Arpin-regulated cell migration. Therefore, this proposal will clarify the Arpin’s function in atomic level, and also provide insights and experimental basis for using Arp2/3 complex as the inhibitory target to design anti-tumor drugs.