Clathrin anchors deubiquitinating enzymes, AMSH and AMSH-like protein, on early endosomes

Genes Cells. 2006 Jun;11(6):593-606. doi: 10.1111/j.1365-2443.2006.00963.x.

Abstract

Endosomal sorting of ubiquitinated membrane proteins for trafficking to lysosomes is executed by a complex of two ubiquitin-binding proteins, Hrs and STAM, that localizes on a microdomain of early endosomes with a flat clathrin coat. AMSH is a deubiquitinating enzyme that interacts with STAM and is implicated in the down-regulation of epidermal growth factor receptor. AMSH has a close homolog, AMSH-like protein (AMSH-LP). Here we show that AMSH-LP is also a deubiquitinating enzyme that acts on early endosomes. We further show that AMSH and AMSH-LP bind to the terminal domain of clathrin heavy chain via a novel clathrin-binding site conserved between these proteins. Exogenously expressed AMSH and AMSH-LP co-localized with clathrin on early endosomes. However, deletion of the clathrin-binding site from the proteins, as well as RNA interference-mediated depletion of clathrin heavy chain, resulted in a failure of AMSH and AMSH-LP to localize on endosomes. In contrast, a mutant of AMSH that lacks the ability to bind STAM localized normally on endosomes. We suggest that AMSH and AMSH-LP are anchored on the early endosomal membrane via interaction with the clathrin coat.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Binding Sites
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Clathrin / metabolism*
  • Clathrin Heavy Chains / genetics
  • Clathrin Heavy Chains / metabolism
  • Endopeptidases / genetics
  • Endopeptidases / metabolism*
  • Endosomal Sorting Complexes Required for Transport
  • Endosomes / metabolism*
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Peptide Hydrolases
  • RNA Interference
  • Ubiquitin Thiolesterase
  • Ubiquitins / metabolism

Substances

  • Carrier Proteins
  • Clathrin
  • Endosomal Sorting Complexes Required for Transport
  • STAMBP protein, human
  • Ubiquitins
  • Clathrin Heavy Chains
  • Endopeptidases
  • Peptide Hydrolases
  • STAMBPL1 protein, human
  • Ubiquitin Thiolesterase