Glutamate induces focal adhesion kinase tyrosine phosphorylation and actin rearrangement in heterologous mGluR1-expressing CHO cells via calcium/calmodulin signaling.
Group 1 metabotropic glutamate receptors (mGluR1 and mGluR5) stimulate phospholipase C (PLC) and lead to mobilization of intracellular Ca(2+) and activation of protein kinase C (PKC). In this investigation, using heterologous receptor-expressing Chinese hamster ovary (CHO) cells, we showed that stimulation of mGluR1 or mGluR5 with glutamate rapidly increases tyrosine phosphorylation of focal adhesion kinase (FAK) (maximum at 1-3 min) in a dose-dependent manner (half-maximal responses at approximately 2 microM). In mGluR1-expressing cells, the glutamate-induced increase of FAK tyrosine phosphorylation was blocked by not only the PLC inhibitor, U73122, but also depletion of intracellular Ca(2+) and effectively abrogated by calmodulin (CaM) inhibitors, calmidazolium and fluphenazine. However, neither the PKC inhibitor, GF109203X, nor the CaM kinase II inhibitor, KN-62, inhibited glutamate-stimulated FAK tyrosine phosphorylation. Stimulation of mGluR1 caused a marked increase in actin stress fiber formation. Importantly, this actin rearrangement was prevented by the CaM inhibitor, but not by the PKC inhibitor and is thus in a good agreement with the signaling cascade of the mGluR1-FAK pathway. These results suggest that the Ca(2+)/CaM signaling and its downstream FAK tyrosine phosphorylation play an important role in cellular function of mGluR1.
Shinohara
Y
Y
Department of Biological Sciences, Faculty of Medicine, Kyoto University, Yoshida, Sakyo-ku, Kyoto, Japan.
Nakajima
Y
Y
Nakanishi
S
S
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives / Q000494:pharmacology; D000199:Actins / Q000378:metabolism*; D000818:Animals; D016466:CHO Cells; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism; D006224:Cricetinae; D003599:Cytoskeleton / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D004492:Edetic Acid / Q000494:pharmacology; D004533:Egtazic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D051416:Focal Adhesion Protein-Tyrosine Kinases; D022001:Focal Adhesions; D018698:Glutamic Acid / Q000494:pharmacology*; D007211:Indoles / Q000494:pharmacology; D007700:Kinetics; D008301:Maleimides / Q000494:pharmacology; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011760:Pyrrolidinones / Q000494:pharmacology; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate / Q000235:genetics / Q000502:physiology*; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection; D010738:Type C Phospholipases / Q000378:metabolism
D000199:Actins; D004791:Enzyme Inhibitors; D004963:Estrenes; D007211:Indoles; D008301:Maleimides; D011760:Pyrrolidinones; D064529:Receptor, Metabotropic Glutamate 5; D018094:Receptors, Metabotropic Glutamate; D011994:Recombinant Proteins; C104077:metabotropic glutamate receptor type 1; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D018698:Glutamic Acid; D004533:Egtazic Acid; C063302:KN 62; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D004492:Edetic Acid; D011505:Protein-Tyrosine Kinases; D051416:Focal Adhesion Protein-Tyrosine Kinases; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010738:Type C Phospholipases; C070515:bisindolylmaleimide I