Effect of phorbol 12-myristate 13-acetate on Ca2+-ATPase activity in rat liver nuclei.
The effect of phorbol 12-myristate 13-acetate (PMA) on Ca(2+)-ATPase activity in rat liver nuclei was investigated. Ca(2+)-ATPase activity was calculated by subtracting Mg(2+)-ATPase activity from (Ca(2+)-Mg(2+)-ATPase activity. The nuclear Ca(2+)-ATPase activity was significantly increased by the presence of PMA (2-20 microM) in the enzyme reaction mixture; the maximum effect was seen at 10 microM. The PMA (10 microM)-increased Ca(2+)-ATPase activity was not blocked by the presence of staurosporine (2 microM) or dibucaine (2 and 10 microM), an inhibitor of protein kinase. Meanwhile, vanadate (20 and 100 microM) caused a significant reduction in the nuclear Ca(2+)-ATPase activity increased by PMA (10 microM). The present finding suggests that PMA has an activating effect on liver nuclear Ca(2+)-ATPase independent of protein kinase.
Oishi
K
K
Laboratory of Metabolism and Endocrinology, Graduate School of Nutritional Sciences, University of Shizuoka, Japan.
Yamaguchi
M
M
D000255:Adenosine Triphosphate / Q000494:pharmacology; D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism*; D002467:Cell Nucleus / Q000201:enzymology*; D003992:Dibucaine / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D008099:Liver / Q000648:ultrastructure*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D019311:Staurosporine; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014638:Vanadates / Q000494:pharmacology
D000470:Alkaloids; D014638:Vanadates; D000255:Adenosine Triphosphate; D000252:Calcium-Transporting ATPases; D019311:Staurosporine; D003992:Dibucaine; D013755:Tetradecanoylphorbol Acetate