Effect of vitamin D status on cyclic AMP-dependent protein kinase activity and its heat-stable inhibitor in chick kidney.
Cyclic AMP-dependent protein kinase activity in supernatants of homogenates of kidneys from vitamin D-deficient chicks is decreased to 70% of the level measured in kidneys from normal chicks. Activity was restored to normal by oral administration of vitamin D or 1,25-dihydroxyvitamin D3 for 1 or 2 weeks. Both isozymes of cAMP-dependent protein kinase were reduced to the same extent by vitamin D deficiency. The decreased enzyme activity could not be accounted for by a shift to the particulate fraction nor by an increased requirement for cyclic AMP. A heat stable, trichloroacetic acid-precipitable, trypsin-labile inhibitor of protein kinase activity was identified and quantitated in kidneys from vitamin D-deficient chicks (16 to 26 units/mg of protein) and from those given vitamin D (2 to 6 units/mg of protein). The measured difference in inhibitor levels could not be attributed to differential stability in kidney homogenates from vitamin D-deficient or -repleted chicks. The observed increase in inhibitor level with vitamin D deficiency is not sufficient to account for the decrease in cyclic AMP-dependent protein kinase activity, suggesting that the total amount of this enzyme activity is reduced in vitamin D deficiency.
D000375:Aging; D000818:Animals; D002117:Calcitriol / Q000494:pharmacology*; D002352:Carrier Proteins / Q000378:metabolism*; D002645:Chickens; D000242:Cyclic AMP / Q000494:pharmacology*; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes / Q000378:metabolism; D007668:Kidney / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D007700:Kinetics; D011494:Protein Kinases / Q000302:isolation & purification / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology; D014807:Vitamin D / Q000494:pharmacology*; D014808:Vitamin D Deficiency / Q000201:enzymology*
D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D007527:Isoenzymes; C015482:protein kinase modulator; D014807:Vitamin D; D000242:Cyclic AMP; D011494:Protein Kinases; D002117:Calcitriol