环磷酸腺苷对大鼠脑（钠+钾）-ATP酶活性的调节

Regulation of rat brain (Na+ +K+)-ATPase activity by cyclic AMP.

作者信息

Lingham R B, Sen A K

出版信息

Biochim Biophys Acta. 1982 Jun 14;688(2):475-85. doi: 10.1016/0005-2736(82)90359-5.

Abstract

The interaction between the (Na+ +K+)-ATPase and the adenylate cyclase enzyme systems was examined. Cyclic AMP, but not 5'-AMP, cyclic GMP or 5'-GMP, could inhibit the (Na+ +K+)-ATPase enzyme present in crude rat brain plasma membranes. On the other hand, the cyclic AMP inhibition could not be observed with purified preparations of (Na+ +K+)-ATPase enzyme. Rat brain synaptosomal membranes were prepared and treated with either NaCl or cyclic AMP plus NaCl as described by Corbin, J., Sugden, P., Lincoln, T. and Keely, S. ((1977) J. Biol. Chem. 252, 3854-3861). This resulted in the dissociation and removal of the catalytic subunit of a membrane-bound cyclic AMP-dependent protein kinase. The decrease in cyclic AMP-dependent protein kinase activity was accompanied by an increase in (Na+ +K+)-ATPase activity. Exposure of synaptosomal membranes containing the cyclic AMP-dependent protein kinase holoenzyme to a specific cyclic AMP-dependent protein kinase inhibitor resulted in an increase in (Na+ +K+)-ATPase enzyme activity. Synaptosomal membranes lacking the catalytic subunit of the cyclic-AMP-dependent protein kinase did not show this effect. Reconstitution of the solubilized membrane-bound cyclic AMP-dependent protein kinase, in the presence of a neuronal membrane substrate protein for the activated protein kinase, with a purified preparation of (Na+ +K+)-ATPase, resulted in a decrease in overall (Na+ +K+)-ATPase activity in the presence of cyclic AMP. Reconstitution of the protein kinase alone or the substrate protein alone, with the (Na+ +K+)-ATPase has no effect on (Na+ +K+)-ATPase activity in the absence or presence of cyclic AMP. Preliminary experiments indicate that, when the activated protein kinase and the substrate protein were reconstituted with the (Na+ +K+)-ATPase enzyme, there appeared to be a decrease in the Na+-dependent phosphorylation of the Na+-ATPase enzyme, while the K+-dependent dephosphorylation of the (Na+ +K+)-ATPase was unaffected.

摘要

研究了（Na⁺+K⁺）-ATP酶与腺苷酸环化酶系统之间的相互作用。环磷酸腺苷（cAMP），而非5'-AMP、环磷酸鸟苷（cGMP）或5'-GMP，能够抑制大鼠脑粗制质膜中存在的（Na⁺+K⁺）-ATP酶。另一方面，用纯化的（Na⁺+K⁺）-ATP酶制剂未观察到环磷酸腺苷的抑制作用。按照科尔宾、萨格登、林肯和基利（（1977年）《生物化学杂志》252卷，3854 - 3861页）所述制备大鼠脑突触体膜，并用氯化钠或环磷酸腺苷加氯化钠进行处理。这导致膜结合的环磷酸腺苷依赖性蛋白激酶催化亚基的解离和去除。环磷酸腺苷依赖性蛋白激酶活性的降低伴随着（Na⁺+K⁺）-ATP酶活性的增加。将含有环磷酸腺苷依赖性蛋白激酶全酶的突触体膜暴露于特异性环磷酸腺苷依赖性蛋白激酶抑制剂，导致（Na⁺+K⁺）-ATP酶活性增加。缺乏环磷酸腺苷依赖性蛋白激酶催化亚基的突触体膜未显示出这种效应。在存在活化蛋白激酶的神经元膜底物蛋白的情况下，将溶解的膜结合环磷酸腺苷依赖性蛋白激酶与纯化的（Na⁺+K⁺）-ATP酶制剂重构，在存在环磷酸腺苷的情况下导致总体（Na⁺+K⁺）-ATP酶活性降低。单独将蛋白激酶或单独将底物蛋白与（Na⁺+K⁺）-ATP酶重构，在不存在或存在环磷酸腺苷的情况下对（Na⁺+K⁺）-ATP酶活性均无影响。初步实验表明，当活化蛋白激酶和底物蛋白与（Na⁺+K⁺）-ATP酶重构时，Na⁺-ATP酶的Na⁺依赖性磷酸化似乎减少，而（Na⁺+K⁺）-ATP酶的K⁺依赖性去磷酸化未受影响。