Dynamics of clathrin and adaptor proteins during endocytosis
- 1 November 2006
- journal article
- Published by American Physiological Society in American Journal of Physiology-Cell Physiology
- Vol. 291 (5), C1072-C1081
- https://doi.org/10.1152/ajpcell.00160.2006
Abstract
The endocytic adaptor complex AP-2 colocalizes with the majority of clathrin-positive spots at the cell surface. However, we previously observed that AP-2 is excluded from internalizing clathrin-coated vesicles (CCVs). The present studies quantitatively demonstrate that AP-2 disengages from sites of endocytosis seconds before internalization of the nascent CCV. In contrast, epsin, an alternate adaptor for clathrin at the plasma membrane, disappeared, along with clathrin. This suggests that epsin remains an integral part of the CCV throughout endocytosis. Clathrin spots at the cell surface represent a heterogeneous population: a majority (70%) of the spots disappeared with a time course of 4 min, whereas a minority (22%) remained static for ≥30 min. The static clathrin spots undergo constant subunit exchange, suggesting that although they are static structures, these spots comprise functional clathrin molecules, rather than dead-end aggregates. These results support a model where AP-2 serves a cargo-sorting function before endocytosis, whereas alternate adaptors, such as epsin, actually link cargo to the clathrin coat surrounding nascent endocytic vesicles. These data also support a role for static clathrin, providing a nucleation site for endocytosis.Keywords
This publication has 44 references indexed in Scilit:
- Coupling between Clathrin-Coated-Pit Invagination, Cortactin Recruitment, and Membrane Scission Observed in Live CellsCell, 2005
- Mechanisms of Dense Core Vesicle Recapture following “Kiss and Run” (“Cavicapture”) Exocytosis in Insulin-secreting CellsJournal of Biological Chemistry, 2004
- An Assembly-incompetent Mutant Establishes a Requirement for Dynamin Self-assembly in Clathrin-mediated Endocytosis In VivoMolecular Biology of the Cell, 2004
- Understanding Living Clathrin-Coated PitsTraffic, 2004
- Endocytic Adaptor Molecules Reveal an Endosomal Population of Clathrin by Total Internal Reflection Fluorescence MicroscopyJournal of Biological Chemistry, 2004
- Sorting it outThe Journal of cell biology, 2003
- Clathrin-mediated endocytosis in AP-2–depleted cellsThe Journal of cell biology, 2003
- The ENTH domainFEBS Letters, 2002
- Simultaneous Binding of PtdIns(4,5)P 2 and Clathrin by AP180 in the Nucleation of Clathrin Lattices on MembranesScience, 2001
- The Ear of α-Adaptin Interacts with the COOH-terminal Domain of the Eps15 ProteinPublished by Elsevier ,1996