The C-terminal 165 amino acids of the plasma membrane Ca(2+)-ATPase confer Ca2+/calmodulin sensitivity on the Na+,K(+)-ATPase alpha-subunit.
The C-terminal 165 amino acids of the plasma membrane Ca(2+)-ATPase confer Ca2+/calmodulin sensitivity on the Na+,K(+)-ATPase alpha-subunit.
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质膜 Ca(2)-ATP 酶的 C 端 165 个氨基酸赋予 Na,K()-ATP 酶 α 亚基 Ca2/钙调蛋白敏感性。
DOI：
10.1002/j.1460-2075.1995.tb06975.x
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Takeyasu,K
中科院分区：
文献类型：
--
作者：
Ishii,T;Takeyasu,K
将含有钙调素结合自抑制结构域的大鼠脑质膜（PM）Ca（2+）-ATP酶II的C末端165个氨基酸连接到哇巴因敏感的鸡Na+，K（+）-ATP酶α 1亚基的C末端。这种嵌合分子在哇巴因抗性小鼠L细胞中的表达通过[3 H]哇巴因的高亲和力结合来保证。在存在Ca 2 +/钙调蛋白的情况下，该嵌合分子表现出哇巴因可诱导的Na+，K（+）-ATP酶活性;在不存在Ca 2 +/钙调蛋白的情况下，推定的嵌合ATP酶活性不存在，并以剂量依赖性方式被Ca 2 +/钙调蛋白激活。此外，该嵌合分子仅在存在Ca 2 +/钙调蛋白的情况下才能结合对鸡Na+，K（+）-ATP酶α 1亚基特异性的单克隆IgG 5，这表明该嵌合体中IgG 5的表位在不存在Ca 2 +/钙调蛋白的情况下被掩蔽，而在存在Ca 2 +/钙调蛋白的情况下被暴露。这些结果表明PM Ca（2+）-ATP酶的钙调素结合自抑制结构域与Na+，K（+）-ATP酶α 1亚基的特定区域之间存在直接相互作用，该亚基在结构上与PM Ca（2+）-ATP酶同源。推导的氨基酸序列的比较揭示了Na+，K（+）-ATP酶内可能与PM Ca（2+）-ATP酶的自抑制结构域相互作用的几个可能区域。
The C‐terminal 165 amino acids of the rat brain plasma membrane (PM) Ca(2+)‐ATPase II containing the calmodulin binding auto‐inhibitory domain was connected to the C‐terminus of the ouabain sensitive chicken Na+,K(+)‐ATPase alpha 1 subunit. Expression of this chimeric molecule in ouabain resistant mouse L cells was assured by the high‐affinity binding of [3H]ouabain. In the presence of Ca2+/calmodulin, this chimeric molecule exhibited ouabain inhibitable Na+,K(+)‐ATPase activity; the putative chimeric ATPase activity was absent in the absence of Ca2+/calmodulin and activated by Ca2+/calmodulin in a dose‐dependent manner. Furthermore, this chimeric molecule could bind monoclonal IgG 5 specific to the chicken Na+,K(+)‐ATPase alpha 1 subunit only in the presence of Ca2+/calmodulin, suggesting that the epitope for IgG 5 in this chimera is masked in the absence of Ca2+/calmodulin and uncovered in their presence. These results propose a direct interaction between the calmodulin binding auto‐inhibitory domain of the PM Ca(2+)‐ATPase and the specific regions of the Na+,K(+)‐ATPase alpha 1 subunit that are structurally homologous to the PM Ca(2+)‐ATPase. A comparison of the deduced amino acid sequences revealed several possible regions within the Na+,K(+)‐ATPase that might interact with the auto‐inhibitory domain of the PM Ca(2+)‐ATPase.