Dictyostelium Tom1 participates to an ancestral ESCRT-0 complex

Traffic. 2009 Feb;10(2):161-71. doi: 10.1111/j.1600-0854.2008.00855.x. Epub 2008 Nov 11.

Abstract

Sorting of ubiquitinated proteins to multivesicular bodies (MVBs) in mammalian cells relies on proteins with a Vps27/Hrs/STAM (VHS) domain. Here, we show that the amoeba Dictyostelium presents only one protein with a VHS domain: DdTom1. We demonstrate that the VHS domain of DdTom1 is followed by a Golgi-localized, gamma-ear-containing, ADP-ribosylation-factor-binding and Tom1 (GAT) domain that binds ubiquitin, and by a non-conserved C-terminal domain that can recruit clathrin, EGFr pathway substrate 15 and tumor susceptibility gene 101, a component of the MVB biogenesis machinery [endosomal complexes required for transport (ESCRT) complexes]. Both VHS and GAT domains interact with phospholipids and therefore could ensure the recruitment of DdTom1 to endosomal membranes. We propose that DdTom1 participates in an ancestral ESCRT-0 complex implicated in the sorting of ubiquitinated proteins into MVBs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Vesicular Transport / metabolism
  • Amino Acid Motifs
  • Animals
  • Cell-Derived Microparticles / metabolism*
  • Clathrin / metabolism
  • Cytoplasm / metabolism
  • Dictyostelium / genetics
  • Dictyostelium / metabolism*
  • Dictyostelium / ultrastructure
  • Gene Deletion
  • Humans
  • Lysosomes / metabolism
  • Microscopy, Electron
  • Protein Binding
  • Protozoan Proteins / genetics
  • Protozoan Proteins / metabolism*

Substances

  • Adaptor Proteins, Vesicular Transport
  • Clathrin
  • Protozoan Proteins