PI(3)P结合家族蛋白WIPI1-4是一类具有重要功能的蛋白，与肿瘤、心血管疾病、神经退行性疾病等密切相关。近年研究发现WIPI蛋白在细胞自噬过程中发挥着重要作用。本组前期利用线虫进行遗传筛选发现多个多细胞生物特有的自噬蛋白，并发现PI(3)P效应蛋白ATG18在线虫中有两个同源蛋白ATG-18和EPG-6，在自噬通路中发挥着不同作用。哺乳动物细胞中ATG18的同源蛋白进一步分化为四个WIPI1-4，它们如何共同参与和调控自噬通路目前尚不清楚。本研究组前期构建了Wipi1-4基因敲除小鼠并发现它们神经系统表型各不相同。本研究拟采用细胞生物学和生物化学等方法深入研究WIPI蛋白在自噬通路发挥功能的分子机理，并通过观察各基因敲除小鼠对不同组织和功能的影响在整体动物水平观察它们如何相互协调发挥作用。我们希望通过对WIPI蛋白功能的研究深入阐明自噬通路的分子机制并为相关疾病的治疗提供理论依据。

PI(3)P binding family proteins WIPI (WD-repeat protein interacting with phosphoinositides) 1-4, which belongs to WDR (WD40-repeat domain) proteins, are regulatory beta-propeller platforms that enable the assembly of multiprotein complexes and function in many essential biological functions including cell cycle control, apoptosis, signal transduction pathways, RNA metabolism, chromatin assembly and vesicular trafficking. Previous studies have demonstrated the role of WIPIs in the pathogenesis of a variety of human diseases, including cancer, cardiovascular diseases, and neurodegenerative diseases. Recent findings demonstrated the critical role of WIPIs in the autophagy pathway. Autophagy is a highly conserved cytoprotective mechanism for lysosomal clearance of aggregated proteins and damaged organelles. A hallmark for autophagy is the formation of double-membraned autophagosomes which is dependent of the production of PI(3)P generated by class III PI3K complex. Members of WIPI proteins are currently the only known conserved and essential PI(3)P effectors in autophagy. Our previous studies using genetic screen in C. elegans revealed a group of metazoan-specific autophagy genes, named “epg” genes. The C. elegans homologs of yeast essential autophagy gene Atg18 are atg-18 and epg-6, which function differentially in the autophagosome formation process. EPG-6 directly interacts with ATG-2 and regulates progression of omegasomes to autophagosomes, while ATG-18 may regulate association of protein aggregates, LGG-1 puncta and omegasomes. The mammalian ATG18 homologs are WIPI1-4, which could further fall into two paralogous groups, WIPI1/2 (ATG-18) and WIPI3/4 (EPG-6). How these four proteins function cooperatively in the autophagy pathway is still unclear. We plan to generate the WIPI1-4 knockout cell using CRISPR/Cas9 and knockout MEF from Wipi1-4 knockout mice. Through studying the autophagy defect in these cells, we will do hierarchal analysis of WIPIs in autophagosome formation to determine their functional difference in the autophagy pathway. We will also utilize biochemical methods to identify specific targets of WIPIs in the autophagy and other pathways. To study their function in vivo, we will further analyze the tissue-specific function of different WIPI proteins using Wipi1-4 knockout mice. This study will provide new insights into the molecular basis of autophagosome formation and potential therapeutic targets for treating related human diseases.