Guanine nucleotide binding proteins regulate epithelial Na+ channels.
Guanine nucleotide binding proteins regulate epithelial Na+ channels.
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鸟嘌呤核苷酸结合蛋白调节上皮Na通道。
DOI：
10.1007/978-1-4684-5934-0_31
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发表时间：
1991
影响因子：
--
通讯作者：
Cantiello,HF
中科院分区：
文献类型：
--
作者：
Ausiello,DA;Stow,JL;Patenaude,CR;Cantiello,HF
通过转运蛋白调节离子运动对于吸收和分泌上皮细胞特别重要，细胞内离子浓度必须仔细平衡才能使细胞进行跨上皮电解运动。上皮细胞对环境信号做出剧烈反应的能力部分依赖于它们诱导一系列次级信使的能力，包括由激素与基底膜受体相互作用产生的细胞内信号钙、pH和cAMP(1)。在顶膜上产生的生理反应(例如，增加的Na+转运)被认为是从这些第二信使系统的传递发展而来的，例如，通过生化途径中的蛋白激酶，导致一个或多个顶膜蛋白的磷酸化，包括Na+通道本身(2)。最近对部分纯化的A6细胞顶膜Na+通道的研究表明，该复合体中的一种蛋白质(至少由7种蛋白质组成)被cAMP依赖的蛋白激酶(3)磷酸化。据报道，血管加压素激活V2受体后，细胞内cAMP浓度的变化可以增加紧致上皮细胞中的Na+转运，如蟾蜍膀胱和A6蟾蜍肾细胞系(4，5)。
Regulation of ion movements via transport proteins is of particular importance in absorbing and secreting epithelia where the intracellular ionic concentrations must be carefully balanced to enable the cells to perform transepithelial electrolytic movements. The ability of epithelia to respond in an acute fashion to environmental signals relies, in part, on their capacity to induce a set of secondary messengers, including the intracellular signals Ca2+, pH and cAMP, generated by interaction of hormones with receptors at the basolateral membrane (1). The resultant physiological response at the apical membrane (e.g. increased Na+transport) is assumed to develop from the transmission of these second messenger systems through, for example, protein kinases in biochemical pathways which result in the phosphorylation of one or more apical membrane proteins, including the Na+channel itself (2). Recent evidence from studies of partially purified Na+channels from the apical membrane of A6 cells suggest that one of the proteins in this complex (of at least 7 proteins) is phosphorylated by cAMP-dependent protein kinase (3). Changes in the intracellular cAMP concentration upon activation of the V2 receptor by vasopressin have been reported to increase Na+transport in tight epithelia, such as toad urinary bladder and the A6 toad kidney cell line (4,5).