Regulation of WASH-dependent Actin Polymerization and Protein Trafficking by Ubiquitination

Cell. 2013 Feb 28;152(5):1051-64. doi: 10.1016/j.cell.2013.01.051.

Abstract

Endosomal protein trafficking is an essential cellular process that is deregulated in several diseases and targeted by pathogens. Here, we describe a role for ubiquitination in this process. We find that the E3 RING ubiquitin ligase, MAGE-L2-TRIM27, localizes to endosomes through interactions with the retromer complex. Knockdown of MAGE-L2-TRIM27 or the Ube2O E2 ubiquitin-conjugating enzyme significantly impaired retromer-mediated transport. We further demonstrate that MAGE-L2-TRIM27 ubiquitin ligase activity is required for nucleation of endosomal F-actin by the WASH regulatory complex, a known regulator of retromer-mediated transport. Mechanistic studies showed that MAGE-L2-TRIM27 facilitates K63-linked ubiquitination of WASH K220. Significantly, disruption of WASH ubiquitination impaired endosomal F-actin nucleation and retromer-dependent transport. These findings provide a cellular and molecular function for MAGE-L2-TRIM27 in retrograde transport, including an unappreciated role of K63-linked ubiquitination and identification of an activating signal of the WASH regulatory complex.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Actins / metabolism
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism*
  • Endosomes / metabolism
  • Gene Knockdown Techniques
  • Golgi Apparatus / metabolism
  • Humans
  • Microfilament Proteins / metabolism
  • Multiprotein Complexes / metabolism*
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Protein Transport*
  • Proteins / genetics
  • Proteins / metabolism*
  • RNA Interference
  • Ubiquitin-Conjugating Enzymes / metabolism
  • Ubiquitination

Substances

  • Actins
  • DNA-Binding Proteins
  • MAGEL2 protein, human
  • Microfilament Proteins
  • Multiprotein Complexes
  • Nuclear Proteins
  • Proteins
  • TRIM27 protein, human
  • WASH protein, human
  • Ubiquitin-Conjugating Enzymes