A FAM21-containing WASH Complex Regulates Retromer-Dependent Sorting

Dev Cell. 2009 Nov;17(5):699-711. doi: 10.1016/j.devcel.2009.09.009.

Abstract

The Arp2/3 complex regulates endocytosis, sorting, and trafficking, yet the Arp2/3-stimulating factors orchestrating these distinct events remain ill defined. WASH (Wiskott-Aldrich Syndrome Protein and SCAR Homolog) is an Arp2/3 activator with unknown function that was duplicated during primate evolution. We demonstrate that WASH associates with tubulin and localizes to early endosomal subdomains, which are enriched in Arp2/3, F-actin, and retromer components. Although WASH localized with activated receptors, it was not essential for endocytosis. However, WASH did regulate retromer-mediated retrograde CI-MPR trafficking, which required its association with endosomes, Arp2/3-directed F-actin regulation, and tubulin interaction. Moreover, WASH exists in a multiprotein complex containing FAM21, which links WASH to endosomes and is required for WASH-dependent retromer-mediated sorting. Significantly, without WASH, retromer tubulation was exaggerated, supporting a model wherein WASH links retromer-mediated cargo containing tubules to microtubules for Golgi-directed trafficking and generates F-actin-driven force for tubule scission.

Publication types

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

MeSH terms

  • Actin-Related Protein 2-3 Complex / metabolism
  • Actins / metabolism
  • Amino Acid Sequence
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Cell Line, Tumor
  • Endocytosis*
  • Humans
  • Microtubule-Associated Proteins / genetics
  • Microtubule-Associated Proteins / metabolism*
  • Microtubules / metabolism
  • Molecular Sequence Data
  • Protein Binding
  • Protein Transport
  • Tubulin / metabolism
  • Wiskott-Aldrich Syndrome Protein / genetics
  • Wiskott-Aldrich Syndrome Protein / metabolism*

Substances

  • Actin-Related Protein 2-3 Complex
  • Actins
  • Carrier Proteins
  • Microtubule-Associated Proteins
  • Tubulin
  • Wiskott-Aldrich Syndrome Protein