WASH and Tsg101/ALIX-dependent diversion of stress-internalized EGFR from the canonical endocytic pathway

Nat Commun. 2015 Jun 12:6:7324. doi: 10.1038/ncomms8324.

Abstract

Stress exposure triggers ligand-independent EGF receptor (EGFR) endocytosis, but its post-endocytic fate and role in regulating signalling are unclear. We show that the p38 MAP kinase-dependent, EGFR tyrosine kinase (TK)-independent EGFR internalization induced by ultraviolet light C (UVC) or the cancer therapeutic cisplatin, is followed by diversion from the canonical endocytic pathway. Instead of lysosomal degradation or plasma membrane recycling, EGFR accumulates in a subset of LBPA-rich perinuclear multivesicular bodies (MVBs) distinct from those carrying EGF-stimulated EGFR. Stress-internalized EGFR co-segregates with exogenously expressed pre-melanosomal markers OA1 and fibrillar PMEL, following early endosomal sorting by the actin polymerization-promoting WASH complex. Stress-internalized EGFR is retained intracellularly by continued p38 activity in a mechanism involving ubiquitin-independent, ESCRT/ALIX-dependent incorporation onto intraluminal vesicles (ILVs) of MVBs. In contrast to the internalization-independent EGF-stimulated activation, UVC/cisplatin-triggered EGFR activation depends on EGFR internalization and intracellular retention. EGFR signalling from this MVB subpopulation delays apoptosis and might contribute to chemoresistance.

Publication types

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

MeSH terms

  • DNA-Binding Proteins / metabolism*
  • Endocytosis*
  • Endosomal Sorting Complexes Required for Transport / metabolism*
  • ErbB Receptors / metabolism*
  • HeLa Cells
  • Humans
  • Microfilament Proteins / metabolism*
  • Oxidative Stress
  • Protein Transport
  • Signal Transduction
  • Transcription Factors / metabolism*
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • DNA-Binding Proteins
  • Endosomal Sorting Complexes Required for Transport
  • Microfilament Proteins
  • Transcription Factors
  • Tsg101 protein
  • WASH protein, human
  • ErbB Receptors
  • p38 Mitogen-Activated Protein Kinases