J BIOCHEM TOXICOLOGY Volume 7,Number 2,1992
Oxidant and Angiotensin II-hduced Subcellular Translocation of Protein Kinase C in Pulmonary Artery Endothelid Cells Jawaharalal M . Patel, K. Madhavi Sekharam, and Edward R. Block Division of P u ~ o M Medicine, ~ ~ University of Florida College of Medicine and the Veterans Affairs Medical Center, Gainesville, Florida 32608-1197, USA
ABSTRACT: We recently reported that nitrogen dioxide (NO,), an environmental oxidant, alters the dynamics of the plasma membrane lipid bilayer structure, resulting in increased phosphatidylserine content and angiotensin I1 (Ang 11) receptor binding. Angiotensin I1 is known to elicit receptor-mediated stimulation of diacylglycerol (DAG) production in pulmonary artery endothelial cells. Because protein kinase C (PKC) is a phosphatidylserine-dependent enzyme and is activated by DAG, we examined whether NO, resulted in activation andlor translocation of PKC from predominantly cytosolic to membrane fractions of these cells. We also evaluated whether NO, exposure resulted in increased production of DAG in pulmonary artery endothelial cells. Exposure to 5 ppm NO, for 1-24 hr resulted in significant increases in PKC activity in the cytosolic and membrane fractions ( p
Oxidant and Angiotensin II-hduced Subcellular Translocation of Protein Kinase C in Pulmonary Artery Endothelid Cells Jawaharalal M . Patel, K. Madhavi Sekharam, and Edward R. Block Division of P u ~ o M Medicine, ~ ~ University of Florida College of Medicine and the Veterans Affairs Medical Center, Gainesville, Florida 32608-1197, USA
ABSTRACT: We recently reported that nitrogen dioxide (NO,), an environmental oxidant, alters the dynamics of the plasma membrane lipid bilayer structure, resulting in increased phosphatidylserine content and angiotensin I1 (Ang 11) receptor binding. Angiotensin I1 is known to elicit receptor-mediated stimulation of diacylglycerol (DAG) production in pulmonary artery endothelial cells. Because protein kinase C (PKC) is a phosphatidylserine-dependent enzyme and is activated by DAG, we examined whether NO, resulted in activation andlor translocation of PKC from predominantly cytosolic to membrane fractions of these cells. We also evaluated whether NO, exposure resulted in increased production of DAG in pulmonary artery endothelial cells. Exposure to 5 ppm NO, for 1-24 hr resulted in significant increases in PKC activity in the cytosolic and membrane fractions ( p
