线粒体自噬受体蛋白FUNDC1与LC3复合物的结构及功能研究

Alterations in mitophagy are involved in many serious diseases. Mitophagy receptors mediate mitochondrial autophagy through interaction with LC3. FUNDC1 is a novel hypoxia-induced mitophagy receptor which was recently discovered by Dr. Feng Du and his collaborators. However, the 3-D structures of Fundc1 itself and its homologues are unavailabe. Recently, we aquired the crystals of the truncated protein of FUNDC1 with members of LC3 family, and in this project we will further refine the complex crystal and determine its structure. Based on this complex structure, we will then engineer a serials of key mutants to elucidate the mechanism of how the interactions between FUNDC1 and LC3 to regulate the mitophagy using biochemistry and cell biology methods. Our study will provide insights into not only FUNDC1 itself but also FUNDC1 mediated-mitophagy and will be helpful for us to better understand the working mechanism of other mitophagy receptors such as NIX and BNIP3 in mammals and ATG32 in yeast.

线粒体自噬异常与多种疾病相关。线粒体自噬受体通过与LC3相互作用介导线粒体选择性自噬。本课题组成员冯杜博士及其合作者最近发现一个新的哺乳动物线粒体自噬受体FUNDC1，介导低氧诱导的线粒体自噬，但FUNDC1本身及其同源蛋白的三维空间结构均未被研究报道。最近，我们已获得FUNDC1片段蛋白和LC3家族成员的复合物晶体，本项目将进一步优化晶体、解析结构并基于结构设计影响相互作用的关键氨基酸突变体，在生化和细胞水平上阐明FUNDC1与LC3相互作用介导线粒体自噬的分子机理。本课题的研究结果将拓宽和加深对FUNDC1本身及其介导的线粒体选择性自噬的理解，对哺乳动物另外两个线粒体自噬受体NIX和BNIP3以及酵母ATG32介导线粒体自噬的研究有重要的指导意义。

线粒体自噬异常与多种疾病相关。线粒体自噬受体通过与LC3相互作用介导线粒体选择性自噬。本课题组成员冯杜博士及其合作者最近发现一个新的哺乳动物线粒体自噬受体FUNDC1，介导低氧诱导的线粒体自噬，但FUNDC1本身及其同源蛋白的三维空间结构均未被研究报道。本课题我们已获得磷酸化FUNDC1多肽与LC3B蛋白的复合物晶体，并解析了其三维空间结构，采用ITC实验方法测定了磷酸化修饰对FUNDC1与LC3B相互作用的影响。获得了FUNDC1片段蛋白和LC3B的复合物晶体，进行了晶体的优化并获得分辨率较低的衍射花样图，结合实验证实FUNDC1存在两个位点与LC3B相互作用，后续实验在继续中。本课题还对线粒体自噬受体NIX和BNIP3克隆表达纯化方面得到了一些研究结果，研究了BNIP3的磷酸化位点对其与LC3B相互作用的影响。本课题的研究结果拓宽和加深对FUNDC1本身及其介导的线粒体选择性自噬的理解，对哺乳动物另外两个线粒体自噬受体NIX和BNIP3以及酵母ATG32介导线粒体自噬的研究有重要的指导意义。