Activations of mitogen-activated protein kinases and phospholipase D in A7r5 vascular smooth muscle cells.
Activation of mitogen-activated protein kinases (MAPKs) was examined in the A7r5 rat vascular smooth muscle cell line. Treatment of A7r5 cells with vasopressin, phorbol ester (PMA), or serum resulted in activation of two MAPKs, Erk-1 and Erk-2. Phosphatidylinositol-specific phospholipase C was activated in response to vasopressin but not to PMA. Vasopressin and PMA both caused maximal activation of PLD within 5 minutes. Application of bacterial phospholipase D (PLD) to A7r5 cells increased phosphatidic acid to levels similar to those seen with vasopressin or PMA. Acute exposure of the cells to vasopressin, PMA, or PLD increased phosphorylation of many of the same cytosolic and membrane proteins. However, bacterial PLD did not promote significant activation of Erk-1 and Erk-2. Phosphatidic acid and lysophosphatidic acid (LPA) likewise did not stimulate MAPK activity in A7r5 cells. Serum and vasopressin stimulated DNA synthesis when present for more than 30 min, while PLD, PMA, phosphatidic acid, and LPA were not mitogenic. These data suggest that activations of MAPKs and PLD are concurrent but independent responses to vasopressin in A7r5 cells. Acute activation of these enzymes is not sufficient to simulate DNA synthesis.
Jones
L G
LG
Department of Cell and Molecular Pharmacology, Medical University of South Carolina, Charleston 29425.
Ella
K M
KM
Bradshaw
C D
CD
Gause
K C
KC
Dey
M
M
Wisehart-Johnson
A E
AE
Spivey
E C
EC
Meier
K E
KE
D000818:Animals; D001011:Aorta / Q000201:enzymology; D004789:Enzyme Activation; D007295:Inositol Phosphates / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1; D009131:Muscle, Smooth, Vascular / Q000201:enzymology*; D010712:Phosphatidic Acids / Q000494:pharmacology; D010714:Phosphatidylethanolamines / Q000378:metabolism; D054801:Phosphoinositide Phospholipase C; D010739:Phospholipase D / Q000378:metabolism*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D051381:Rats; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014667:Vasopressins / Q000494:pharmacology
D007295:Inositol Phosphates; D010712:Phosphatidic Acids; D010714:Phosphatidylethanolamines; D014667:Vasopressins; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019950:Mitogen-Activated Protein Kinase 1; D010727:Phosphoric Diester Hydrolases; D054801:Phosphoinositide Phospholipase C; D010739:Phospholipase D; D013755:Tetradecanoylphorbol Acetate