title: WASH and Tsg101/ALIX-dependent diversion of stress-internalized EGFR from the canonical endocytic pathway.
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.
authors.affiliation: Department of Cell Biology, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Tomas
authors.affiliation: Department of Cell Biology, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
authors.forename: Simon O
authors.initials: SO
authors.lastname: Vaughan
authors.affiliation: Department of Cell Biology, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
authors.forename: Thomas
authors.initials: T
authors.lastname: Burgoyne
authors.affiliation: Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Sorkin
authors.affiliation: Cancer Research UK Drug-DNA Interactions Research Group, UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street, London WC1E 6BT, UK.
authors.forename: John A
authors.initials: JA
authors.lastname: Hartley
authors.affiliation: Cancer Research UK Drug-DNA Interactions Research Group, UCL Cancer Institute, Paul O'Gorman Building, University College London, 72 Huntley Street, London WC1E 6BT, UK.
authors.forename: Daniel
authors.initials: D
authors.lastname: Hochhauser
authors.affiliation: Department of Cell Biology, UCL Institute of Ophthalmology, University College London, 11-43 Bath Street, London EC1V 9EL, UK.
authors.forename: Clare E
authors.initials: CE
authors.lastname: Futter
mesh_terms: D004268:DNA-Binding Proteins / Q000378:metabolism*; D004705:Endocytosis; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism*; D018384:Oxidative Stress; D021381:Protein Transport; D015398:Signal Transduction; D014157:Transcription Factors / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism; D000099177:Tsg101 Protein
chemical_list: D004268:DNA-Binding Proteins; D056827:Endosomal Sorting Complexes Required for Transport; D066246:ErbB Receptors; D008840:Microfilament Proteins; D014157:Transcription Factors; D048051:p38 Mitogen-Activated Protein Kinases; D000099177:Tsg101 Protein; C549919:WASH protein, human