G protein-coupled receptor activation rapidly stimulates focal adhesion kinase phosphorylation at Ser-843. Mediation by Ca2+, calmodulin, and Ca2+/calmodulin-dependent kinase II.
A rapid increase in the tyrosine phosphorylation of focal adhesion kinase (FAK) has been extensively documented in cells stimulated by multiple signaling molecules, but little is known about the regulation of FAK phosphorylation at serine residues. Stimulation of Swiss 3T3 cells with the G protein-coupled receptor agonists bombesin, vasopressin, or bradykinin induced an extremely rapid (within 5 s) increase in FAK phosphorylation at Ser-843. The phosphorylation of this residue preceded FAK phosphorylation at Tyr-397, the major autophosphorylation site, and FAK phosphorylation at Ser-910. Treatment of intact cells with ionomycin stimulated a rapid increase in FAK phosphorylation at Ser-843, indicating that an increase in intracellular Ca2+ concentration ([Ca2+]i) is a potential pathway leading to FAK-Ser-843 phosphorylation. Indeed, treatment with agents that prevent an agonist-induced increase in [Ca2+]i (e.g. thapsigargin or BAPTA (1,2-bis(O-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid)), interfere with calmodulin function (e.g. trifluoperazine, W13, and W7), or block Ca2+/calmodulin-dependent protein kinase II (CaMKII) activation (KN93) or expression (small interfering RNA) abrogated the rapid FAK phosphorylation at Ser-843 induced by bombesin, bradykinin, or vasopressin. Furthermore, activated CaMKII directly phosphorylated the recombinant COOH-terminal region of FAK at a residue equivalent to Ser-843. Thus, our results demonstrate that G protein-coupled receptor activation induces rapid FAK phosphorylation at Ser-843 through Ca2+, calmodulin, and CaMKII.
Fan
Robert S
RS
Division of Digestive Diseases, Department of Medicine, David Geffen School of Medicine, Center for Ulcer Research and Education, Digestive Diseases Research Center and Molecular Biology Institute, University of California, Los Angeles, California, USA.
Jácamo
Rodrigo O
RO
Jiang
Xiaohua
X
Sinnett-Smith
James
J
Rozengurt
Enrique
E
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D001839:Bombesin / Q000494:pharmacology; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D017931:DNA Primers; D004533:Egtazic Acid / Q000031:analogs & derivatives; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D051379:Mice; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D043562:Receptors, G-Protein-Coupled / Q000378:metabolism*; D012694:Serine / Q000378:metabolism*; D015398:Signal Transduction; D019284:Thapsigargin / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology
D017931:DNA Primers; D043562:Receptors, G-Protein-Coupled; D014667:Vasopressins; D012694:Serine; D004533:Egtazic Acid; D019284:Thapsigargin; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496051:Ptk2 protein, mouse; D054732:Calcium-Calmodulin-Dependent Protein Kinase Type 2; D017871:Calcium-Calmodulin-Dependent Protein Kinases; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D001839:Bombesin