Sardet C, Counillon L, Franchi A, Pouysségur J
Centre de Biochimie-CNRS, Nice, France.
Science. 1990 Feb 9;247(4943):723-6. doi: 10.1126/science.2154036.
The Na+/H+ antiporter, which regulates intracellular pH in virtually all cells, is one of the best examples of a mitogen- and oncogene-activated membrane target whose activity rapidly changes on stimulation. The activating mechanism is unknown. A Na+/H+ antiporter complementary DNA fragment was expressed in Escherichia coli as a beta-galactosidase fusion protein, and a specific antibody to the fusion protein was prepared. Use of this antibody revealed that the Na+/H+ antiporter is a 110-kilodalton glycoprotein that is phosphorylated in growing cells. Mitogenic activation of resting hamster fibroblasts and A431 human epidermoid cells with epidermal growth factor, thrombin, phorbol esters, or serum, stimulated phosphorylation of the Na+/H+ antiporter with a time course similar to that of the rise in intracellular pH.
钠氢逆向转运蛋白几乎在所有细胞中调节细胞内pH值，是有丝分裂原和癌基因激活的膜靶点中最好的例子之一，其活性在受到刺激时会迅速变化。激活机制尚不清楚。钠氢逆向转运蛋白互补DNA片段在大肠杆菌中作为β-半乳糖苷酶融合蛋白表达，并制备了针对该融合蛋白的特异性抗体。使用该抗体显示，钠氢逆向转运蛋白是一种110千道尔顿的糖蛋白，在生长细胞中会被磷酸化。用表皮生长因子、凝血酶、佛波酯或血清对静止的仓鼠成纤维细胞和A431人表皮样细胞进行有丝分裂原激活，刺激钠氢逆向转运蛋白的磷酸化，其时间进程与细胞内pH值升高的时间进程相似。
