title: Regulatory role of dynamin-2 in VEGFR-2/KDR-mediated endothelial signaling.
abstract: Vascular endothelial growth factor receptor-2 (VEGFR-2, also known as KDR) is a receptor tyrosine kinase (RTK) regulating mitogenic, chemotactic, permeability, and survival signals in vascular endothelial cells (EC) in response to its ligand, vascular permeability factor/VEGF (VPF/VEGF), arguably the most important angiogenic cytokine. However, the compartmentalization of KDR in EC and the mechanisms regulating this process have not been well defined. Here, we demonstrate that KDR is present on the plasma membrane, on endosomes, and in the perinuclear region of EC and colocalizes with early endosomal antigen (EEA1), caveolin-1, and dynamin-2, a signal transducing GTPase involved in receptor endocytosis. Furthermore, we also observed that dynamin-2 coimmunoprecipitates with KDR and is required for EC signaling/survival. Interestingly, EC overexpressing a mutant form of dynamin deficient in GTP binding (K44A) caused a selective inhibition in KDR protein level and endosomal vesicle formation and induced cell cycle arrest by inducing p21. Taken together, our findings suggest that dynamin-2 regulates KDR expression and function and hence plays an important role in VPF/VEGF mediated angiogenesis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Mayo Clinic Cancer Center, Rochester, Minnesota 55905, USA.
authors.forename: Resham
authors.initials: R
authors.lastname: Bhattacharya
authors.forename: Ningling
authors.initials: N
authors.lastname: Kang-Decker
authors.forename: Deborah A
authors.initials: DA
authors.lastname: Hughes
authors.forename: Priyabrata
authors.initials: P
authors.lastname: Mukherjee
authors.forename: Vijay
authors.initials: V
authors.lastname: Shah
authors.forename: Mark A
authors.initials: MA
authors.lastname: McNiven
authors.forename: Debabrata
authors.initials: D
authors.lastname: Mukhopadhyay
mesh_terms: D015153:Blotting, Western; D051242:Caveolin 1 / Q000378:metabolism; D002453:Cell Cycle; D002462:Cell Membrane / Q000378:metabolism; D049109:Cell Proliferation; D002469:Cell Separation; D002478:Cells, Cultured; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D016207:Cytokines / Q000378:metabolism; D034285:Dynamin II / Q000096:biosynthesis* / Q000502:physiology*; D004705:Endocytosis; D011992:Endosomes / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology / Q000378:metabolism*; D005434:Flow Cytometry; D020558:GTP Phosphohydrolases / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000737:chemistry; D006801:Humans; D047468:Immunoprecipitation; D008565:Membrane Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence; D015233:Models, Statistical; D009154:Mutation; D009389:Neovascularization, Pathologic; D011485:Protein Binding; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D014471:Umbilical Veins / Q000166:cytology; D042461:Vascular Endothelial Growth Factor A / Q000737:chemistry*; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000378:metabolism*; D033921:Vesicular Transport Proteins
chemical_list: C493956:CDKN1A protein, human; D051242:Caveolin 1; D050759:Cyclin-Dependent Kinase Inhibitor p21; D016207:Cytokines; D008565:Membrane Proteins; D042461:Vascular Endothelial Growth Factor A; D033921:Vesicular Transport Proteins; C093846:early endosome antigen 1; D006160:Guanosine Triphosphate; D040301:Vascular Endothelial Growth Factor Receptor-2; D020558:GTP Phosphohydrolases; D034285:Dynamin II