Identification of an essential signaling cascade for mitogen-activated protein kinase activation by angiotensin II in cultured rat vascular smooth muscle cells. Possible requirement of Gq-mediated p21ras activation coupled to a Ca2+/calmodulin-sensitive tyrosine kinase.
In cultured rat vascular smooth muscle cells, angiotensin II (Ang II) induced a rapid increase in mitogen-activated protein kinase (MAPK) activity through the Ang II type 1 receptor, which was insensitive to pertussis toxin but was abolished by the phospholipase C inhibitor, U73122. The Ang II-induced MAPK activation was not affected by the protein kinase C inhibitor, GF109203X, and was only partially impaired by pretreatment with a phorbol ester, whereas both treatments completely prevented MAPK activation by the phorbol ester. Intracellular Ca2+ chelation by TMB-8, but not extracellular Ca2+ chelation or inhibition of Ca2+ influx, abolished Ang II-induced MAPK activation. The calmodulin inhibitor, calmidazolium, and the tyrosine kinase inhibitor, genistein, completely blocked MAPK activation by Ang II as well as by the Ca2+ ionophore A23187. Ang II caused a rapid increase in the binding of GTP to p21(ras), and this was inhibited by genistein, TMB-8, and calmidazolium but not by pertussis toxin or GF109203X. These data suggest that Ang II-induced MAPK activation through the Ang II type 1 receptor could be mediated by p21(ras)activation through a currently unidentified tyrosine kinase that lies downstream of Gq-coupled Ca2+/calmodulin signals.
Eguchi
S
S
Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
Matsumoto
T
T
Motley
E D
ED
Utsunomiya
H
H
Inagami
T
T
D000255:Adenosine Triphosphate / Q000378:metabolism; D000595:Amino Acid Sequence; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001013:Aorta, Thoracic; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured; D004789:Enzyme Activation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004963:Estrenes / Q000494:pharmacology; D019204:GTP-Binding Proteins / Q000378:metabolism*; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D019833:Genistein; D007093:Imidazoles / Q000494:pharmacology; D007211:Indoles / Q000494:pharmacology; D007529:Isoflavones / Q000494:pharmacology; D007700:Kinetics; D008301:Maleimides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D010455:Peptides / Q000138:chemical synthesis / Q000378:metabolism; D037342:Pertussis Toxin; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D011760:Pyrrolidinones / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000037:antagonists & inhibitors; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D004791:Enzyme Inhibitors; D004963:Estrenes; D007093:Imidazoles; D007211:Indoles; D007529:Isoflavones; D008301:Maleimides; D010455:Peptides; D011760:Pyrrolidinones; D010566:Virulence Factors, Bordetella; D000804:Angiotensin II; C060229:1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione; D000001:Calcimycin; C031938:calmidazolium; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D000255:Adenosine Triphosphate; D019833:Genistein; D037342:Pertussis Toxin; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D010738:Type C Phospholipases; D019204:GTP-Binding Proteins; D016283:Proto-Oncogene Proteins p21(ras); C070515:bisindolylmaleimide I; D002118:Calcium