title: Corticotropin and angiotensin induce dephosphorylation of a Mr-20,000 protein in bovine adrenal cells.
abstract: ACTH (1-24) and Angiotensin II, both able to activate steroidogenesis in bovine fasciculata-reticularis cells, each reduced the [32P] incorporation in a cytosolic Mr-20,000 pI 6.8 protein in this cell. Cells preincubated with Sar1-Angiotensin prevented the effect of Angiotensin. Angiotensin 10(-8)M and ACTH 10(-10)M led to an almost complete disappearance of the corresponding radioactive spot on the autoradiograph. The effect was observed as soon as 2 minutes after addition of hormones to the cells. Other activators of steroidogenesis such as 8-bromocyclicAMP (8-BrcAMP), 4 beta-Phorbol-12 beta-Myristate-13 alpha-acetate (PMA) and [9-tryptophan (o-nitrophenylsulfenyl)] substituted ACTH (NPS-ACTH), also reduced the labeling of the Mr-20,000 polypeptide. On the other hand, this effect was not reproduced by insulin or human growth hormone (hGH). On 2-D gels from control, the coincidence of this polypeptide with phosphorylated myosin light chain was not observed. We suggest that the apparent dephosphorylation of this polypeptide may represent a common effect of all steroidogenic agents regardless of their seemingly distinct early actions.
mesh_terms: D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D003366:Cosyntropin / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D066298:In Vitro Techniques; D008970:Molecular Weight; D009218:Myosins / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D013256:Steroids / Q000096:biosynthesis
chemical_list: D010750:Phosphoproteins; D013256:Steroids; D000804:Angiotensin II; D003366:Cosyntropin; D000324:Adrenocorticotropic Hormone; D009218:Myosins