Vascular endothelial growth factor induces activation and subcellular translocation of focal adhesion kinase (p125FAK) in cultured rat cardiac myocytes.
Vascular endothelial growth factor (VEGF) has been proposed to be among the candidate factors with the most potential to play a role in ischemia-induced collateral vessel formation. Recently, we found that VEGF activated the mitogen-activated protein kinase cascade in cultured rat cardiac myocytes. To elucidate how VEGF affects adhesive interaction of cardiac myocytes with the extracellular matrix (ECM), one of the important cell functions, we investigated the molecular mechanism of activation of focal adhesion-related proteins, especially focal adhesion kinase (p125(FAK)), in cultured rat cardiac myocytes. We found that the 2 VEGF receptors, KDR/Flk-1 and Flt-1, were expressed in cardiac myocytes and that KDR/Flk-1 was significantly tyrosine phosphorylated on VEGF stimulation. VEGF induced tyrosine phosphorylation and activation of p125(FAK) as well as tyrosine phosphorylation of paxillin; this was accompanied by subcellular translocation of p125(FAK) from perinuclear sites to the focal adhesions. This VEGF-induced activation of p125(FAK) was inhibited partially by the tyrosine kinase inhibitors genistein and tyrphostin. Activation of p125(FAK) was accompanied by its increased association with adapter proteins GRB2, Shc, and nonreceptor type tyrosine kinase p60(c-src). Furthermore, we confirmed that VEGF induced a significant increase in adhesive interaction between cardiac myocytes and ECM using an electric cell-substrate impedance sensor. These results strongly suggest that p125(FAK) is one of the most important components in VEGF-induced signaling in cardiac myocytes, playing a critical role in adhesive interaction between cardiac myocytes and ECM.
Takahashi
N
N
Department of Cardiovascular Medicine, Graduate School of Medicine, University of Tokyo, Bunkyo-ku, Tokyo. takan-tky@umin.ac.jp
Seko
Y
Y
Noiri
E
E
Tobe
K
K
Kadowaki
T
T
Sabe
H
H
Yazaki
Y
Y
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000818:Animals; D002448:Cell Adhesion / Q000502:physiology; D015815:Cell Adhesion Molecules / Q000032:analysis / Q000378:metabolism*; D002478:Cells, Cultured; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000378:metabolism; D016228:Endothelial Growth Factors / Q000032:analysis / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005109:Extracellular Matrix / Q000737:chemistry / Q000378:metabolism; D005347:Fibroblasts / Q000737:chemistry / Q000166:cytology / Q000378:metabolism; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D051380:GRB2 Adaptor Protein; D019833:Genistein / Q000494:pharmacology; D008222:Lymphokines / Q000032:analysis / Q000378:metabolism*; D018485:Muscle Fibers, Skeletal / Q000737:chemistry / Q000201:enzymology; D009206:Myocardium / Q000737:chemistry* / Q000166:cytology / Q000201:enzymology*; D051419:Paxillin; D010750:Phosphoproteins / Q000032:analysis / Q000378:metabolism; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000032:analysis / Q000378:metabolism*; D011506:Proteins / Q000032:analysis / Q000378:metabolism; D016392:Proto-Oncogene Proteins pp60(c-src) / Q000032:analysis / Q000378:metabolism; D051381:Rats; D020794:Receptor Protein-Tyrosine Kinases / Q000032:analysis / Q000378:metabolism; D017978:Receptors, Growth Factor / Q000032:analysis / Q000378:metabolism; D040262:Receptors, Vascular Endothelial Growth Factor; D055765:Shc Signaling Adaptor Proteins; D015398:Signal Transduction / Q000502:physiology; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D020032:Tyrphostins / Q000494:pharmacology; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors
D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D015815:Cell Adhesion Molecules; D003598:Cytoskeletal Proteins; D016228:Endothelial Growth Factors; D004791:Enzyme Inhibitors; D051380:GRB2 Adaptor Protein; C495950:Grb2 protein, rat; D008222:Lymphokines; D051419:Paxillin; D010750:Phosphoproteins; D011506:Proteins; C496063:Pxn protein, rat; D017978:Receptors, Growth Factor; D055765:Shc Signaling Adaptor Proteins; C528035:Shc1 protein, rat; D000071425:Src Homology 2 Domain-Containing, Transforming Protein 1; D020032:Tyrphostins; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D020794:Receptor Protein-Tyrosine Kinases; D040262:Receptors, Vascular Endothelial Growth Factor; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D016392:Proto-Oncogene Proteins pp60(c-src); C496052:Ptk2 protein, rat