ANPs effect on MARCKS and StAR phosphorylation in agonist-stimulated glomerulosa cells.
Atrial natriuretic peptide (ANP) is a cardiac hormone that inhibits aldosterone secretion induced by all physiologic agonists. The purpose of this study is to explore ANP-induced changes in the phosphorylation of myristoylated alanine-rich C-kinase substrate (MARCKS) and the steroidogenic acute regulatory protein (StAR), in AngII or K(+)-stimulated glomerulosa cells. The data show that ANP completely inhibits the phosphorylation of MARCKS and partially inhibits that of StAR in cells stimulated with K(+). ANP also partially inhibits MARCKS phosphorylation but does not affect StAR phosphorylation in cells stimulated with AngII. These effects appear to be cGMP-independent and at least partially dependent on inhibition of protein kinase C (PKC). To our knowledge, this is the first report of ANP modulating either MARCKS or StAR phosphorylation in [(32)P]-labeled cells. The data also support the hypothesis that ANP inhibits aldosterone secretion acting as a step involved in cholesterol transport to the mitochondria.
Calle
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RA
Program in Cell Signaling, Institute of Molecular Medicine and Genetics, Medical College of Georgia, CB-2801, 1120 15th Street, Augusta, GA 30912, USA. rcalle@mail.mcg.edu
Bollag
W B
WB
White
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S
Betancourt-Calle
S
S
Kent
P
P
D000450:Aldosterone / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D002417:Cattle; D006152:Cyclic GMP / Q000494:pharmacology; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D010750:Phosphoproteins / Q000187:drug effects / Q000378:metabolism*; D010761:Phosphorus Radioisotopes; D010766:Phosphorylation / Q000187:drug effects; D011188:Potassium / Q000494:pharmacology; D011493:Protein Kinase C / Q000494:pharmacology; D015384:Zona Glomerulosa / Q000166:cytology* / Q000187:drug effects; D000098682:Steroidogenic Acute Regulatory Protein
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; D010761:Phosphorus Radioisotopes; D000098682:Steroidogenic Acute Regulatory Protein; D000804:Angiotensin II; D000076250:Myristoylated Alanine-Rich C Kinase Substrate; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D011493:Protein Kinase C; D006152:Cyclic GMP; D011188:Potassium