title: VEGFR2 Trafficking, Signaling and Proteolysis is Regulated by the Ubiquitin Isopeptidase USP8.
abstract: Vascular endothelial growth factor A (VEGF-A) regulates many aspects of vascular function. VEGF-A binding to vascular endothelial growth factor receptor 2 (VEGFR2) stimulates endothelial signal transduction and regulates multiple cellular responses. Activated VEGFR2 undergoes ubiquitination but the enzymes that regulate this post-translational modification are unclear. In this study, the de-ubiquitinating enzyme, USP8, is shown to regulate VEGFR2 trafficking, de-ubiquitination, proteolysis and signal transduction. USP8-depleted endothelial cells displayed altered VEGFR2 ubiquitination and production of a unique VEGFR2 extracellular domain proteolytic fragment caused by VEGFR2 accumulation in the endosome-lysosome system. In addition, perturbed VEGFR2 trafficking impaired VEGF-A-stimulated signal transduction in USP8-depleted cells. Thus, regulation of VEGFR2 ubiquitination and de-ubiquitination has important consequences for the endothelial cell response and vascular physiology.
authors.affiliation: Endothelial Cell Biology Unit, School of Molecular & Cellular Biology, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Gina A
authors.initials: GA
authors.lastname: Smith
authors.affiliation: Endothelial Cell Biology Unit, School of Molecular & Cellular Biology, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Gareth W
authors.initials: GW
authors.lastname: Fearnley
authors.affiliation: Endothelial Cell Biology Unit, School of Molecular & Cellular Biology, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Izma
authors.initials: I
authors.lastname: Abdul-Zani
authors.affiliation: Leeds Institute of Cardiovascular & Metabolic Medicine, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Stephen B
authors.initials: SB
authors.lastname: Wheatcroft
authors.affiliation: Biomedical Health Research Centre & Astbury Centre for Structural Molecular Biology, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Darren C
authors.initials: DC
authors.lastname: Tomlinson
authors.affiliation: School of Biomedical Sciences, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Harrison
authors.affiliation: Endothelial Cell Biology Unit, School of Molecular & Cellular Biology, University of Leeds, LS2 9JT, Leeds, UK.
authors.forename: Sreenivasan
authors.initials: S
authors.lastname: Ponnambalam
mesh_terms: D010450:Endopeptidases / Q000378:metabolism*; D056827:Endosomal Sorting Complexes Required for Transport / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D021381:Protein Transport; D059748:Proteolysis; D015398:Signal Transduction; D043222:Ubiquitin Thiolesterase / Q000378:metabolism*; D054875:Ubiquitination; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*
chemical_list: D056827:Endosomal Sorting Complexes Required for Transport; C000588866:KDR protein, human; D040301:Vascular Endothelial Growth Factor Receptor-2; D010450:Endopeptidases; C541534:USP8 protein, human; D043222:Ubiquitin Thiolesterase
keywords: USP8; VEGF-A; VEGFR2; de-ubiquitination; proteolysis; signal transduction; trafficking