Regulatory role of dynamin-2 in VEGFR-2/KDR-mediated endothelial signaling.
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.
Mesh Terms:
Blotting, Western, Caveolin 1, Cell Cycle, Cell Membrane, Cell Proliferation, Cell Separation, Cells, Cultured, Cyclin-Dependent Kinase Inhibitor p21, Cytokines, Dynamin II, Endocytosis, Endosomes, Endothelium, Vascular, Flow Cytometry, GTP Phosphohydrolases, Guanosine Triphosphate, Humans, Immunoprecipitation, Membrane Proteins, Microscopy, Fluorescence, Models, Statistical, Mutation, Neovascularization, Pathologic, Protein Binding, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction, Umbilical Veins, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factor Receptor-2, Vesicular Transport Proteins
Blotting, Western, Caveolin 1, Cell Cycle, Cell Membrane, Cell Proliferation, Cell Separation, Cells, Cultured, Cyclin-Dependent Kinase Inhibitor p21, Cytokines, Dynamin II, Endocytosis, Endosomes, Endothelium, Vascular, Flow Cytometry, GTP Phosphohydrolases, Guanosine Triphosphate, Humans, Immunoprecipitation, Membrane Proteins, Microscopy, Fluorescence, Models, Statistical, Mutation, Neovascularization, Pathologic, Protein Binding, Reverse Transcriptase Polymerase Chain Reaction, Signal Transduction, Umbilical Veins, Vascular Endothelial Growth Factor A, Vascular Endothelial Growth Factor Receptor-2, Vesicular Transport Proteins
FASEB J.
Date: Oct. 01, 2005
PubMed ID: 16049137
View in: Pubmed Google Scholar
Download Curated Data For This Publication
208306
Switch View:
- Interactions 1