Highly cooperative control of endocytosis by clathrin. Academic Article uri icon

Overview

abstract

  • Clathrin assembles into a dynamic two-dimensional lattice on the plasma membrane where it plays a critical role in endocytosis. To probe the regulation of this process, we used siRNA against clathrin, in combination with single cell assays for transferrin uptake as well as total internal reflection microscopy, to examine how endocytic rates and membrane dynamics depend upon cellular clathrin concentration ([Clathrin]). We find that endocytosis is tightly controlled by [Clathrin] over a very narrow dynamic range such that small changes in [Clathrin] can lead to large changes in endocytic rates, indicative of a highly cooperative process (apparent Hill coefficient, n > 6). The number of clathrin assemblies at the cell surface was invariant over a wide range of [Clathrin]; however, both the amount of clathrin in each assembly and the subsequent membrane dynamics were steeply dependent on [Clathrin]. Thus clathrin controls the structural dynamics of membrane internalization via a strongly cooperative process. We used this analysis to show that one important regulator of endocytosis, the actin cytoskeleton, acts noncompetitively as a modulator of clathrin function.

publication date

  • February 2, 2005

Research

keywords

  • Clathrin
  • Endocytosis

Identity

PubMed Central ID

  • PMC1073659

Scopus Document Identifier

  • 16344371089

Digital Object Identifier (DOI)

  • 10.1091/mbc.e04-08-0739

PubMed ID

  • 15689492

Additional Document Info

volume

  • 16

issue

  • 4