title: Neurotrophins Redirect p75NTR from a clathrin-independent to a clathrin-dependent endocytic pathway coupled to axonal transport.
abstract: The p75 neurotrophin receptor (p75(NTR)) plays multiple roles in neuronal physiology through interactions with many ligands and coreceptors. However, its intracellular neuronal trafficking prior to and after neurotrophin activation is still poorly characterized. We have previously shown that in response to nerve growth factor (NGF), p75(NTR) is retrogradely transported along the axons of motor neurons (MNs) in carriers shared with NGF, brain-derived neurotrophic factor and the tyrosine kinase receptor TrkB. Here, we report that NGF does not enhance the internalization or degradation of p75(NTR), which undergoes a rapid dynamin-dependent and clathrin-independent recycling process in MNs. Instead, incubation of cells with NGF leads to the redirection of a pool of plasma membrane p75(NTR) into clathrin-coated pits. The subsequent internalization of p75(NTR) via clathrin-mediated endocytosis, as well as the activity of Rab5, are essential for the sorting of the p75(NTR)-containing endosomes to the axonal retrograde transport pathway and for the delivery of p75(NTR) to the soma. Our findings suggest that the spatial regulation of p75(NTR) signalling is controlled by these ligand-driven routes of endocytosis.
authors: Molecular Neuropathobiology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, WC2A 3PX, London, UK.|Current address: Molecular Neurobiology Program, Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, NY 10016, USA.
authors: Katrin
authors: K
authors: Deinhardt
authors: Molecular Neuropathobiology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, WC2A 3PX, London, UK.
authors: Alessandra
authors: A
authors: Reversi
authors: Department of Biological Sciences, Imperial College London, SW7 2AZ, London, UK.|Current address: LMU Gene Center, University of Munich, Feodor-Lynen-Str 25, 81377 Muenchen, Germany.
authors: Otto
authors: O
authors: Berninghausen
authors: Department of Biological Sciences, Imperial College London, SW7 2AZ, London, UK.
authors: Colin R
authors: CR
authors: Hopkins
authors: Molecular Neuropathobiology Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, WC2A 3PX, London, UK.
authors: Giampietro
authors: G
authors: Schiavo
mesh_terms: D000818:Animals; D001369:Axons / Q000378:metabolism*; D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism; D002966:Clathrin / Q000737:chemistry / Q000378:metabolism / Q000502:physiology*; D034281:Dynamins / Q000378:metabolism; D004705:Endocytosis; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008954:Models, Biological; D009046:Motor Neurons / Q000378:metabolism; D009414:Nerve Growth Factors / Q000378:metabolism*; D009419:Nerve Tissue Proteins; D051381:Rats; D017978:Receptors, Growth Factor; D017475:Receptors, Nerve Growth Factor / Q000737:chemistry*; D013116:Spinal Cord / Q000378:metabolism; D013696:Temperature; D050656:Transcription Factor AP-2 / Q000378:metabolism
chemical_list: D002966:Clathrin; D009414:Nerve Growth Factors; D009419:Nerve Tissue Proteins; D017978:Receptors, Growth Factor; D017475:Receptors, Nerve Growth Factor; D050656:Transcription Factor AP-2; C068313:Ngfr protein, rat; D034281:Dynamins