title: p75 neurotrophin receptor reduces ligand-induced Trk receptor ubiquitination and delays Trk receptor internalization and degradation.
abstract: Target-derived neurotrophins regulate neuronal survival and growth by interacting with cell-surface tyrosine kinase receptors. The p75 neurotrophin receptor (p75 NTR) is coexpressed with Trk receptors in long-range projection neurons, in which it facilitates neurotrophin binding to Trk and enhances Trk activity. Here, we show that TrkA and TrkB receptors undergo robust ligand-dependent ubiquitination that is dependent on activation of the endogenous Trk activity of the receptors. Coexpression of p75 NTR attenuated ubiquitination of TrkA and TrkB and delayed nerve growth factor-induced TrkA receptor internalization and receptor degradation. These results indicate that p75 NTR may prolong cell-surface Trk-dependent signalling events by negatively regulating receptor ubiquitination.
authors.affiliation: Centre for Neuronal Survival, Montreal Neurological Institute, McGill University, 3801 University Avenue, Montreal, Quebec H3A 2B4, Canada.
authors.forename: Joe P S
authors.initials: JP
authors.lastname: Makkerh
authors.forename: Claire
authors.initials: C
authors.lastname: Ceni
authors.forename: Daniel S
authors.initials: DS
authors.lastname: Auld
authors.forename: François
authors.initials: F
authors.lastname: Vaillancourt
authors.forename: Genevieve
authors.initials: G
authors.lastname: Dorval
authors.forename: Philip A
authors.initials: PA
authors.lastname: Barker
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000494:pharmacology; D002478:Cells, Cultured; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D020932:Nerve Growth Factor / Q000494:pharmacology; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D016716:PC12 Cells; D051381:Rats; D020800:Receptor, Nerve Growth Factor / Q000378:metabolism*; D020917:Receptor, trkA / Q000378:metabolism*; D020813:Receptor, trkB / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection; D025801:Ubiquitin / Q000378:metabolism*
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D020800:Receptor, Nerve Growth Factor; D025801:Ubiquitin; D020932:Nerve Growth Factor; D020917:Receptor, trkA; D020813:Receptor, trkB