Petruniaka V V, Paniushkina E A
Tsitologiia. 1991;33(11):49-54.
The data on hormonal regulation of ATP-driving ion pumps are contradictory depending on the object used: whether native cells or isolated membranes. To eliminate this contrariety, we studied the ion transporting ATPases in saponin-permeabilized cells in the presence of all endogenous regulators. In permeabilized erythrocytes we obtained the presence of Ca(2+)-dependent activation of Ca(2+)-ATPase by factor(s) not affected by calmodulin antagonist R24571. We obtained also Ca(2+)-dependent activation and inhibition of Na+,K(+)-ATPase. At a concentration of Mg(2+)-ions corresponding to the intracellular level (370 microM), the 0.5-0.7 microM Ca(2+)-activated Na+,K(+)-ATPase (up to 3-fold), whereas the 1-5 microM Ca2+ inhibited it. The cyclic AMP (10(-5) M) inhibited or eliminated Ca(2+)-dependent activation. The decrease in Mg(2+)-ion concentration to 50 microM eliminated the activation and strengthened the inhibition, which reached 100% at the 1-2 microM Ca2+ concentration. The washing of membranes with EGTA eliminated Ca2+ effects on Na+,K(+)-ATPase. These data suggest that the ion-transporting ATPases are activated or inhibited by Ca(2+)-dependent regulators whose activities may be changed by protein kinase catalysed phosphorylation.
关于激素对ATP驱动离子泵调节的数据相互矛盾，这取决于所使用的对象：是天然细胞还是分离的膜。为了消除这种矛盾，我们在所有内源性调节因子存在的情况下，研究了皂素通透细胞中的离子转运ATP酶。在通透的红细胞中，我们发现存在一种不受钙调蛋白拮抗剂R24571影响的因子对Ca(2+)-ATP酶的Ca(2+)依赖性激活。我们还发现了Ca(2+)对Na+,K(+)-ATP酶的依赖性激活和抑制。在对应于细胞内水平（370 microM）的Mg(2+)离子浓度下，0.5 - 0.7 microM的Ca(2+)激活Na+,K(+)-ATP酶（高达3倍），而1 - 5 microM的Ca2+则抑制它。环磷酸腺苷（10(-5) M）抑制或消除了Ca(2+)依赖性激活。Mg(2+)离子浓度降低到50 microM消除了激活作用并增强了抑制作用，在1 - 2 microM的Ca2+浓度下抑制作用达到100%。用EGTA洗涤膜消除了Ca2+对Na+,K(+)-ATP酶的影响。这些数据表明，离子转运ATP酶受到Ca(2+)依赖性调节因子的激活或抑制，其活性可能通过蛋白激酶催化的磷酸化作用而改变。
