Mammalian actin-binding protein 1/HIP-55 is essential for the scission of clathrin-coated pits by regulating dynamin-actin interaction

FASEB J. 2015 Jun;29(6):2495-503. doi: 10.1096/fj.14-264259. Epub 2015 Feb 17.

Abstract

Actin and dynamin work cooperatively to drive the invagination and scission of clathrin-coated pits (CCPs). However, little is known about the mechanism that orchestrates the spatiotemporal recruitment of dynamin and actin. Here, we have identified the mammalian actin-binding protein 1 (mAbp1; also called HIP-55 or SH3P7), which could bind to clathrin, actin, as well as dynamin, as an adaptor that links the dynamic recruitment of dynamin and actin for the scission of CCPs. Live-cell imaging reveals that mAbp1 is specifically recruited at a late stage of the long-lived CCPs. mAbp1 knockdown impaired CCP scission by reducing dynamin recruitment at the plasma membrane. However, actin disruption remarkably eliminates mAbp1 recruitment and thus dynamin recruitment. These data suggest that by binding to both clathrin and F-actin, mAbp1 is specifically recruited at a late stage of CCP formation, which subsequently recruits dynamin to CCPs.

Keywords: adaptor protein; membrane trafficking; quantitative live-cell imaging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism*
  • Animals
  • Cell Line, Tumor
  • Clathrin / genetics
  • Clathrin / metabolism*
  • Coated Pits, Cell-Membrane / metabolism*
  • Coated Pits, Cell-Membrane / ultrastructure
  • Dynamins / genetics
  • Dynamins / metabolism*
  • Humans
  • Immunoblotting
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Mice
  • Microfilament Proteins / genetics
  • Microfilament Proteins / metabolism*
  • Microscopy, Electron, Transmission
  • Microscopy, Fluorescence / methods
  • NIH 3T3 Cells
  • Protein Binding
  • Time-Lapse Imaging / methods
  • src Homology Domains / genetics

Substances

  • Actins
  • Clathrin
  • Dbnl protein, mouse
  • HIP-55 protein, human
  • Luminescent Proteins
  • Microfilament Proteins
  • Dynamins