Protein kinase C-mediated regulation of the renal Na(+)/dicarboxylate cotransporter, NaDC-1.
Protein kinase C-mediated regulation of the renal Na(+)/dicarboxylate cotransporter, NaDC-1.
复制标题
蛋白激酶 C 介导的肾 Na(+)/二羧酸协同转运蛋白 NaDC-1 的调节。
DOI：
10.1016/s0005-2736(99)00102-9
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Sun,N
中科院分区：
文献类型：
--
作者：
Pajor,AM;Sun,N
肾近端小管的 Na+/二羧酸协同转运蛋白 NaDC-1 从肾小管滤液中重吸收克雷布斯循环中间体，例如琥珀酸和柠檬酸。尽管慢性代谢性酸中毒和 K+ 缺乏对这种转运蛋白的长期调节已有充分记录，但没有关于 NaDC-1 急性调节的信息。在本研究中，表达 NaDC-1 的非洲爪蟾卵母细胞中琥珀酸的转运被两种蛋白激酶 C 激活剂佛波醇 12-肉豆蔻酸酯、13-乙酸酯 (PMA) 和 sn-1,2-二辛酰甘油 (DOG) 抑制高达 95%。蛋白激酶A的激活对NaDC-1活性没有影响。 PMA 对 NaDC-1 转运的抑制是剂量依赖性的，并且可以通过将卵母细胞与星形孢菌素一起孵育来防止。 NaDC-1 中两个共有蛋白激酶 C 磷酸化位点的突变不影响 PMA 的抑制。 PMA 的抑制作用被细胞松弛素 D 部分阻止，细胞松弛素 D 会破坏微丝和内吞作用。 PMA 处理还与质膜上 NaDC-1 蛋白含量减少约 30% 相关。我们得出结论，PMA 对 NaDC-1 转运活性的抑制是通过内吞作用和转运活性抑制的组合发生的。
The Na+/dicarboxylate cotransporter of the renal proximal tubule, NaDC-1, reabsorbs Krebs cycle intermediates, such as succinate and citrate, from the tubular filtrate. Although long-term regulation of this transporter by chronic metabolic acidosis and K+deficiency is well documented, there is no information on acute regulation of NaDC-1. In the present study, the transport of succinate in Xenopus oocytes expressing NaDC-1 was inhibited up to 95% by two activators of protein kinase C, phorbol 12-myristate, 13-acetate (PMA) and sn-1,2-dioctanoylglycerol (DOG). Activation of protein kinase A had no effect on NaDC-1 activity. The inhibition of NaDC-1 transport by PMA was dose-dependent, and could be prevented by incubation of the oocytes with staurosporine. Mutations of the two consensus protein kinase C phosphorylation sites in NaDC-1 did not affect inhibition by PMA. The inhibitory effects of PMA were partially prevented by cytochalasin D, which disrupts microfilaments and endocytosis. PMA treatment was also associated with a decrease of approximately 30% in the amount of NaDC-1 protein found on the plasma membrane. We conclude that the inhibition of NaDC-1 transport activity by PMA occurs by a combination of endocytosis and inhibition of transport activity.