ACTH-induced change of cAMP-dependent protein-kinase repartition in bovine adrenal cells.
Acute ACTH stimulation of isolated adrenal cells produced a modification of the subcellular distribution of cAMP-dependent protein kinase. Within 20 min, the protein-kinase ratio in all subcellular fractions, particularly in the 175 000 x g supernatant, was increased. Total protein-kinase activity, as well as the specific activity of both the homogenate and particulate enzymatic activities, was decreased while that of the 175 000 x g supernatant was increased. However, the increase of the soluble kinase activity represented only 29-46% of the lost particulate activity. On the other hand, under exchange conditions, the cAMP-binding capacity of all subcellular fractions was similar in control and ACTH-treated cells, except in the 175 000 x g pellet in which it was slightly decreased in ACTH-treated cells. These modifications were observed for supraphysiological (10(-8) M), as well as for physiological (10 (-11) M), concentrations of ACTH. These observations suggest that, after ACTH stimulation, a liberation of free catalytic sub-unit occurs from particulate into the soluble cell compartment, which shows an activation of particulate cAMP-dependent protein-kinase activity.
D000311:Adrenal Glands / Q000187:drug effects* / Q000378:metabolism; D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000818:Animals; D002417:Cattle; D003345:Corticosterone / Q000096:biosynthesis; D000242:Cyclic AMP / Q000378:metabolism*; D004789:Enzyme Activation / Q000187:drug effects; D066298:In Vitro Techniques; D011494:Protein Kinases / Q000378:metabolism*; D013347:Subcellular Fractions / Q000378:metabolism
D000324:Adrenocorticotropic Hormone; D000242:Cyclic AMP; D011494:Protein Kinases; D003345:Corticosterone