title: Regulation of trafficking of activated TrkA is critical for NGF-mediated functions.
abstract: Upon activation by nerve growth factor (NGF), TrkA is internalized, trafficked and sorted through different endosomal compartments. Proper TrkA trafficking and sorting are crucial events as alteration of these processes hinders NGF-mediated functions. However, it is not fully known which proteins are involved in the trafficking and sorting of TrkA. Here we report that Nedd4-2 regulates the trafficking of TrkA and NGF functions in sensory neurons. Depletion of Nedd4-2 disrupts the correct sorting of activated TrkA at the early and late endosome stages, resulting in an accumulation of TrkA in these compartments and, as a result of the reduced trafficking to the degradative pathway, TrkA is either reverted to the cell surface through the recycling pathway or retrogradely transported to the cell body. In addition, Nedd4-2 depletion enhances TrkA signaling and the survival of NGF-dependent dorsal root ganglion neurons, but not those of brain-derived neurotrophic factor-dependent neurons. Furthermore, neurons from a knock-in mouse expressing a TrkA mutant that does not bind Nedd4-2 protein exhibit increased NGF-mediated signaling and cell survival. Our data indicate that TrkA trafficking and sorting are regulated by Nedd4-2 protein.
authors.affiliation: Department of Cell Biology and Pathology, Instituto de Neurociencias de Castilla y León (INCyL), Universidad de Salamanca, Salamanca 37007, Spain.
authors.forename: Tao
authors.initials: T
authors.lastname: Yu
authors.forename: Laura
authors.initials: L
authors.lastname: Calvo
authors.forename: Begoña
authors.initials: B
authors.lastname: Anta
authors.forename: Saray
authors.initials: S
authors.lastname: López-Benito
authors.forename: Eileen
authors.initials: E
authors.lastname: Southon
authors.forename: Moses V
authors.initials: MV
authors.lastname: Chao
authors.forename: Lino
authors.initials: L
authors.lastname: Tessarollo
authors.forename: Juan C
authors.initials: JC
authors.lastname: Arévalo
mesh_terms: D000818:Animals; D019208:Brain-Derived Neurotrophic Factor / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D002470:Cell Survival; D002478:Cells, Cultured; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism; D005727:Ganglia, Spinal / Q000201:enzymology / Q000378:metabolism; D055879:Gene Knock-In Techniques; D051379:Mice; D000075702:Nedd4 Ubiquitin Protein Ligases; D020932:Nerve Growth Factor / Q000378:metabolism*; D021381:Protein Transport; D051381:Rats; D020917:Receptor, trkA / Q000235:genetics / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000201:enzymology / Q000378:metabolism; D015398:Signal Transduction; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism
chemical_list: D019208:Brain-Derived Neurotrophic Factor; D056827:Endosomal Sorting Complexes Required for Transport; D020932:Nerve Growth Factor; C000618479:NEDD4L protein, rat; D000075702:Nedd4 Ubiquitin Protein Ligases; C000618484:Nedd4 protein, rat; C000618461:Nedd4l protein, mouse; D044767:Ubiquitin-Protein Ligases; D020917:Receptor, trkA