Effect of phorbol 12-myristate 13-acetate on Ca2+-ATPase activity in rat liver nuclei

✍ Scribed by Kimiko Oishi; Masayoshi Yamaguchi

• Publisher: John Wiley and Sons
• Year: 1994
• Tongue: English
• Weight: 426 KB
• Volume: 55
• Category: Article
• ISSN: 0730-2312
• DOI: 10.1002/jcb.240550203

✦ Synopsis

The effect of phorbol 12-myristate 13-acetate (PMA) on Ca2+-ATPase activity in rat h e r nuclei was investigated. Ca2 +-ATPase activity was calculated by subtracting Mg2+ -ATPase activity from (Ca2 +-Mg2 +)-ATPase activity. The nuclear Ca2+-ATPase activity was significantly increased by the presence of PMA (2-20 pM) in the enzyme reaction mixture; the maximum effect was seen at 10 pM. The PMA (10 pM)-increased Ca2+-ATPase activity was not blocked by the presence of staurosporine (2 pM) or dibucaine (2 and 10 pM), an inhibitor of protein kinase. Meanwhile, vanadate (20 and 100 FM) caused a significant reduction in the nuclear Ca*+-ATPase activity increased by PMA (10 pM). The present finding suggests that PMA has an activating effect on liver nuclear Ca2+-ATPase independent of protein kinase.