Protein kinase C activates an H+ (equivalent) conductance in the plasma membrane of human neutrophils.
Protein kinase C activates an H+ (equivalent) conductance in the plasma membrane of human neutrophils.
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蛋白激酶 C 激活人类中性粒细胞质膜中的 H（等效）电导。
DOI：
10.1073/pnas.88.23.10816
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发表时间：
1991
影响因子：
11.1
通讯作者：
Sergio Grinstein
中科院分区：
文献类型：
--
作者：
A. Nanda;Sergio Grinstein
当中性粒细胞被激活时，它们产生代谢酸的速度大大增加。Na+/H+交换部分阻止了细胞内的酸化，但在名义上没有Na+和HCO3-的情况下，H+排出的一个相当大的成分仍然存在。在这份报告中，我们确定了一个可能的H+传导途径对H+排出的贡献及其激活模式。在未受刺激的细胞中，H+电导较低，且不受去极化的影响。设计了一种实验系统，以最大限度地减少与中性粒细胞激活相关的代谢酸产生和膜电位变化。使用该体系，β-佛波酯可提高质膜的H~+(当量)通透性。佛波酯诱导通量的方向由电化学H+梯度决定。此外，反离子通过流变路径的平行迁移对于膜上可测量的H+当量的置换是必要的。这些发现表明H+通量是导电的。β-佛波酯的作用可被甘油二酯和甲氧西林模拟，并可被星形孢子素阻断，而α-佛波酯则无效。总之，这些发现表明，蛋白激酶C的刺激诱导了人中性粒细胞质膜H+电导的激活。还提出了激活单独的、对巴菲罗星A1敏感的H+排出机制的初步证据，可能是液泡型H(+)-ATPase。
The rate of metabolic acid generation by neutrophils increases greatly when they are activated. Intracellular acidification is prevented in part by Na+/H+ exchange, but a sizable component of H+ extrusion persists in the nominal absence of Na+ and HCO3-. In this report we determined the contribution to H+ extrusion of a putative H+ conductive pathway and its mode of activation. In unstimulated cells, H+ conductance was found to be low and unaffected by depolarization. An experimental system was designed to minimize the metabolic acid generation and membrane potential changes associated with neutrophil activation. By using this system, beta-phorbol esters were shown to increase the H+ (equivalent) permeability of the plasma membrane. The direction of the phorbol ester-induced fluxes was dictated by the electrochemical H+ gradient. Moreover, the parallel migration of a counterion through a rheogenic pathway was necessary for the displacement of measurable amounts of H+ equivalents across the membrane. These findings suggest that the H+ flux is conductive. The effect of beta-phorbol esters was mimicked by diacylglycerol and mezerein and was blocked by staurosporine, whereas alpha-phorbol esters were ineffective. Together, these findings indicate that stimulation of protein kinase C induces the activation of an H+ conductance in the plasma membrane of human neutrophils. Preliminary evidence for activation of a separate, bafilomycin A1-sensitive H+ extrusion mechanism, likely a vacuolar type H(+)-ATPase, is also presented.