Ca2+ -activated K+ conductance in internally perfused snail neurons is enhanced by protein phosphorylation.
Ca2+ -activated K+ conductance in internally perfused snail neurons is enhanced by protein phosphorylation.
复制标题
内部灌注的蜗牛神经元中 Ca2 激活的 K 电导通过蛋白质磷酸化而增强。
DOI：
10.1073/pnas.79.13.4207
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发表时间：
1982
影响因子：
11.1
通讯作者：
H. Reuter
中科院分区：
文献类型：
--
作者：
J. D. de Peyer;A. B. Cachelin;I. Levitan;H. Reuter
去极化电压阶跃诱导电压钳位，内部灌注神经元从蜗牛Haplusroseneri内向和外向电流。将环AMP依赖性蛋白激酶（ATP：蛋白磷酸转移酶，EC 2.7.1.37）的催化亚基添加到内部灌注介质中导致净外向电流增加，对内向电流没有明显影响。被5，5 '-二硫代双（2-硝基苯甲酸）灭活的催化亚基没有影响，表明净外向电流的增加是由蛋白磷酸化引起的，而不是蛋白灌注的非特异性作用。将外部Ca 2+浓度从10降低到1 mM消除了催化亚基的作用，表明Ca 2+在这种响应中起着重要作用。这一建议得到以下事实的支持：催化亚基的刺激可以通过增加内部灌注介质中的Ca 2+浓度来模拟，并且可以通过用10 mM EGTA进行细胞内灌注来防止。这些结果与环腺苷酸依赖性蛋白磷酸化调节这些细胞中钙激活的K+电导的假设是一致的。
Depolarizing voltage steps induce inward and outward currents in voltage-clamped, internally perfused neurons from the snail Helix roseneri. Addition of the catalytic subunit of cyclic AMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) to the internal perfusing medium results in an increase in the net outward current, with no apparent effect on the inward current. Catalytic subunit inactivated by 5,5'-dithiobis(2-nitrobenzoic acid) is without effect, indicating that the increase in net outward current results from protein phosphorylation rather than an unspecific effect of protein perfusion. Decreasing the external Ca2+ concentration from 10 to 1 mM eliminates the effect of catalytic subunit, suggesting that Ca2+ plays an important role in this response. This suggestion is supported by the fact that the stimulation by catalytic subunit can be mimicked by increasing the Ca2+ concentration in the internal perfusion medium and can be prevented by intracellular perfusion with 10 mM EGTA. The results are consistent with the hypothesis that cyclic AMP-dependent protein phosphorylation regulates the Ca2+-activated K+ conductance in these cells.