title: Clathrin and phosphatidylinositol-4,5-bisphosphate regulate autophagic lysosome reformation.
abstract: Autophagy is a lysosome-based degradation pathway. During autophagy, lysosomes fuse with autophagosomes to form autolysosomes. Following starvation-induced autophagy, nascent lysosomes are formed from autolysosomal membranes through an evolutionarily conserved cellular process, autophagic lysosome reformation (ALR), which is critical for maintaining lysosome homeostasis. Here we report that clathrin and phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P(2)) regulate ALR. Combining a screen of candidates identified through proteomic analysis of purified ALR tubules, and large-scale RNAi knockdown, we unveiled a tightly regulated molecular pathway that controls lysosome homeostasis, in which clathrin and PtdIns(4,5)P(2) are the central components. Our functional study demonstrates the central role of clathrin and its associated proteins in cargo sorting, phospholipid conversion, initiation of autolysosome tubulation, and proto-lysosome budding during ALR. Our data not only uncover a molecular pathway by which lysosome homeostasis is maintained through the ALR process, but also reveal unexpected functions of clathrin and PtdIns(4,5)P(2) in lysosome homeostasis.
authors.affiliation: State Key Laboratory of Biomembrane and Membrane Biotechnology, Tsinghua University-Peking University Center for Life Sciences, School of Life Science, Tsinghua University, Beijing 100084, China.
authors.forename: Yueguang
authors.initials: Y
authors.lastname: Rong
authors.forename: Mei
authors.initials: M
authors.lastname: Liu
authors.forename: Liang
authors.initials: L
authors.lastname: Ma
authors.forename: Wanqing
authors.initials: W
authors.lastname: Du
authors.forename: Hanshuo
authors.initials: H
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Tian
authors.forename: Zhen
authors.initials: Z
authors.lastname: Cao
authors.forename: Ying
authors.initials: Y
authors.lastname: Li
authors.forename: He
authors.initials: H
authors.lastname: Ren
authors.forename: Chuanmao
authors.initials: C
authors.lastname: Zhang
authors.forename: Lin
authors.initials: L
authors.lastname: Li
authors.forename: She
authors.initials: S
authors.lastname: Chen
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Xi
authors.forename: Li
authors.initials: L
authors.lastname: Yu
mesh_terms: D000818:Animals; D001343:Autophagy / Q000502:physiology*; D002478:Cells, Cultured; D002966:Clathrin / Q000378:metabolism*; D055785:Gene Knockdown Techniques; D006706:Homeostasis / Q000502:physiology; D008247:Lysosomes / Q000378:metabolism / Q000502:physiology*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism; D017853:Phosphotransferases (Alcohol Group Acceptor) / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D040901:Proteomics / Q000379:methods; D051381:Rats; D014162:Transfection
chemical_list: D002966:Clathrin; D019269:Phosphatidylinositol 4,5-Diphosphate; D010743:Phospholipids; D017853:Phosphotransferases (Alcohol Group Acceptor); C020077:1-phosphatidylinositol-4-phosphate 5-kinase