Zylinska L, Gromadzinska E, Lachowicz L
II Department of Biochemistry, Medical University of Lodz, Poland.
Cell Signal. 1996 Sep;8(6):443-8. doi: 10.1016/s0898-6568(96)00080-0.
The in vitro effect of okadaic acid on basal phorbol 12-myristate 13-acetate (PMA)-, and cyclic adenosine monophosphate (cAMP)-stimulated Mg(2+)-dependent Ca(2+)-adenosine triphosphatase (ATPase) activity in synaptosomal membranes isolated from rat brain cortex and cerebellum was investigated. The basal activity was enhanced by okadaic acid in both examined regions. This inhibitor differed in the regulation of Mg2+, Ca(2+)-ATPase activity in PMA- and cAMP-incubated membranes. Stimulation by calmodulin (CaM) of basal Mg2+, Ca(2+)-ATPase activity declined in cortex and cerebellum after treatment with okadaic acid. The presence of PMA or cAMP decreases the stimulatory effect of CaM. These results suggest that Mg2+, Ca(2+)-ATPase activity in the rat-brain synaptosomal membrane may be regulated in vitro by dephosphorylation processes.
研究了冈田酸对从大鼠脑皮层和小脑中分离出的突触体膜中基础佛波醇12 -肉豆蔻酸酯13 -乙酸酯（PMA）和环磷酸腺苷（cAMP）刺激的镁离子依赖型钙离子三磷酸腺苷酶（ATPase）活性的体外作用。在两个检测区域中，基础活性均被冈田酸增强。该抑制剂在PMA和cAMP孵育的膜中对镁离子、钙离子ATPase活性的调节有所不同。在用冈田酸处理后，皮层和小脑中钙调蛋白（CaM）对基础镁离子、钙离子ATPase活性的刺激作用下降。PMA或cAMP的存在降低了CaM的刺激作用。这些结果表明，大鼠脑突触体膜中的镁离子、钙离子ATPase活性在体外可能受去磷酸化过程的调节。
