Rab39A调控自噬的机制及其在神经退行性疾病中功能研究

HOPS复合物与自噬特异性SNAREs调控自噬体与溶酶体识别与融合，但目前对于HOPS招募的机制知之甚少。我们发现定位于溶酶体上的Rab39A和自噬体上的Rab2可直接结合HOPS组分，二者可能协同桥连自噬体与溶酶体加速膜融合。我们鉴定C9ORF72是Rab39A潜在的GEF，在体外促进Rab39A-GTP的产生。C9ORF72突变影响自噬并导致神经退行性疾病ALS的发生，但机制不明。本研究将围绕“C9ORF72-Rab39A调控的自噬及其在ALS疾病中的作用”展开：利用体外的膜融合体系证明Rab39A与Rab2协同招募HOPS的机制；结合细胞学和体外实验阐明C9ORF72作为Rab39A的GEF调控自噬的机制；在小鼠疾病模型和病人来源的iPSCs中，探索C9ORF72是否通过自噬的调控影响ALS的发生与进程。本研究有望揭示自噬调控新机制，并为ALS疾病的防治提供理论依据与潜在靶点。

HOPS complex and autophagic specific SNAREs mediate autophagosome and lysosome recognition and fusion, however, little is known about the mechanism of HOPS recruitment. Recently, we found that Rab39A mainly localizes on lysosomes while Rab2 localizes on autophagosomes. Both of them can directly bind to HOPS components, which may synergistically bridge autophagosomes and lysosomes to accelerate membrane fusion. We also identified C9ORF72 as a potential GEF for Rab39A to promote the production of Rab39A-GTP in vitro. Mutation of C9ORF72 affects autophagy and causes neurodegenerative disease such as ALS, but the mechanism remains elusive. In this study, we will focus on “C9ORF72-Rab39A regulated autophagy and its role in ALS”. The in vitro membrane fusion assay will be used to demonstrate the mechanism of Rab39A and Rab2 in the recruitment of HOPS. Cytology and in vitro experiments will be used to elucidate the mechanism of C9ORF72 in autophagy regulation as the GEF of Rab39A. Combine disease mouse model and patient derived iPSCs, we will explore whether C9ORF72 influences the occurrence and progression of ALS through autophagy regulation. These studies will reveal new mechanisms of autophagy regulation and provide theoretical basis and potential therapeutic targets for treatment of ALS.