VAMP8 function reveals tight linkage between endocytic recycling and endocytosis
Abstract
Clathrin-mediated endocytosis (CME) is a multistage process that involves the initiation and stabilization of clathrin-coated pits (CCPs) that invaginate and finally detach from the plasma membrane to form clathrin-coated vesicles (CCVs). Given that Soluble N-ethylmaleimide-sensitive factor attachment receptor (SNARE) proteins are essential for downstream vesicle targeting and fusion events, their recruitment into nascent CCVs has been suggested to be a prerequisite for CME progression. However, which and how SNARE proteins regulate CME remains to be explored. Here, we showed that siRNA-mediated knockdown of the R-SNARE, vesicle-associated membrane protein 8 (VAMP8) impairs CCP initiation, stabilization, and invagination and strongly inhibits CME. Mechanistically, recruitment of VAMP8 to CCVs is not required for CME. Instead, depletion of VAMP8 inhibits recycling of endocytic cargoes and as exemplified here by transferrin receptor, skews their trafficking toward lysosomal degradation. VAMP8 depletion therefore indirectly impairs CCV formation and inhibits CME by depleting endocytic cargo. Overall, our study provides insights into the crosstalk between endocytosis and endocytic recycling of CME cargo and demonstrates the critical role for cargo recruitment in stabilizing nascent CCPs to regulate CME.
Article Details
Journal Info
Proceedings of the National Academy of Sciences
National Academy of Sciences
Authors (13)
Ailing Liu
Key Laboratory of Material Simulation Methods and Software of Ministry of Education, College of Physics
Yueping Li
Department of Clinical Laboratory of The First Affiliated Hospital, Ministry of Education Key Laboratory of Rare Pediatric Diseases, Institute of Cytology and Genetics, Hengyang Medical School, University of South China
Zheng Huang
College of Materials, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, College of Energy, School of Life Sciences, College of Physical Science and Technology, and Discipline of Intelligent Instrument and Equipment
Wen Chen
Department of Immunology, St. Jude Children’s Research Hospital
Peiliu Xu
Department of Clinical Laboratory of The First Affiliated Hospital, National Health Commission Key Laboratory of Birth Defect Research and Prevention, Ministry of Education Key Laboratory of Rare Pediatric Diseases, Institute of Cytology and Genetics of School of Basic Medical Sciences, Hengyang Medical School, University of South China
Xiangying Wei
Department of Oceanography, Fujian Key Laboratory on Conservation and Sustainable Utilization of Marine Biodiversity, Fuzhou Institute of Oceanography, College of Geography and Oceanography, Minjiang University
Guosheng Hu
Biomedical Research Center of South China, College of Life Sciences, Fujian Normal University
Shuangquan Liu
Xiaoxia Liu
Yaohui He
Fujian Provincial Key Laboratory of Innovative Drug Target Research, School of Pharmaceutical Sciences, Xiamen University
Danling Wang
Department of Clinical Laboratory of The First Affiliated Hospital, Ministry of Education Key Laboratory of Rare Pediatric Diseases, Institute of Cytology and Genetics, Hengyang Medical School, University of South China
Sandra L. Schmid
Department of Cell Biology, University of Texas Southwestern Medical Center
Zhiming Chen
State Key Laboratory of Deep Earth Processes and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences