[The role of phosphoinositides, protein kinase C and protein kinase A in the K+ regulatory signal transduction in human adrenocortical cells].
The messenger mechanisms mediating K+ regulatory signals in human adrenocorticocytes were studied. It was shown that potassium ions initiated decay of polyphosphoinositides to inositolphosphates and obviously diacylglycerol. The latter compounds activate protein kinase C as affected by different agonists. Using western blotting method we showed translocation of PKCalpha from cytosol to membranes after adrenal tissue preincubation in the medium with increased K+ content (8.5 mM). Translocation means activation of the enzyme. Activity of PKC increased in the microsomal fraction and did not change in cytosol. Increased concentration of K+ in the incubation medium also activates protein kinase A, although to a lesser extent compared to PKC. Unlike PKC activity of PKA was changed in cytosol as well. The possibility of involvement of several messenger systems in K+ signal transduction in human adrenocortical cells as well as the hypothesis on cross-talk between messenger mechanisms for main physiological agonists controlling aldosterone biosynthesis in the adrenals are discussed.
Pushkar'ov
V M
VM
Kovzun
O I
OI
Tron'ko
M D
MD
Kostiuchenko
N M
NM
Mykosha
O S
OS
D000302:Adrenal Cortex / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D000450:Aldosterone / Q000096:biosynthesis; D002478:Cells, Cultured; D003470:Culture Media; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D010716:Phosphatidylinositols / Q000378:metabolism*; D047748:Pituitary ACTH Hypersecretion / Q000378:metabolism; D011188:Potassium / Q000378:metabolism* / Q000494:pharmacology; D011493:Protein Kinase C / Q000378:metabolism*; D015398:Signal Transduction
D003470:Culture Media; D010716:Phosphatidylinositols; D000450:Aldosterone; D017868:Cyclic AMP-Dependent Protein Kinases; D011493:Protein Kinase C; D011188:Potassium