ATP敏感钾通道的研究进展

New Light on the Study of K _(ATP) Channels.

ATP敏感钾通道(KATP)是一组将细胞膜电活动与细胞代谢联系在一起的重要通道.该通道是由磺酰脲受体(SUR)和内向整流钾通道(KIR6x)亚单位组成的异源四聚体(SUR/KIR6x)4.SUR与KIR6x基因在染色体上配对存在.KIR6x亚单位形成通道的电流孔道,SUR使通道对磺酰脲类药物、钾通道开放剂和Mg2+NDPs等调节因子敏感.不同亚型KATP通道特性由SUR与KIR6x亚单位组成决定.KATP通道门控受[ATP]i和[ADP]i调节,膜磷脂(PIPs)抑制通道对ATP的敏感性,细胞磷酸转移系统也参与ATP/ADP对通道的调节机制;磺酰脲类复合物(SUs)抑制KATP通道,钾通道开放剂(KCOs)激活KATP通道;G蛋白以及PKA、PKC、PKG等信使物质也参与通道的调节.KATP通道对胰岛素的分泌、心肌缺血预适应以及血管的张力起重要调节作用.

Adenosine triphosphate (ATP) sensitive potassium channels (K ATP ) which couple cell metabolism to electrical activity are heteromultimers of sulfonylurea receptor (SUR) and inward rectifier K + channel (K IR 6 x) subunits associated with 1∶1 stoichiometry as a tetramer (SUR/ K IR 6 x) 4. SUR and K IR 6 x genes come in pairs in chromosome. K IR 6 x subunit forms the electrical pore of the K ATP channel and SUR endows the K ATP channel with sensitivity to regulators such as sulfonylurea drugs, K + channel opening drugs, and Mg 2+ nucleotides. The characterizations of K ATP channel subtypes are determined by the combination of SUR and K IR 6 x subunits. The gates of K ATP channels are ion gated by [ATP] i and [ADP] i. Phosphatidylinositol phosphates (PIPs) antagonized ATP inhibition of K ATP channels and cellular phosphotransfer cascades also involve in the regulation mechanism of ATP/ADP. K ATP channels are inhibited by sulfonylurea complexes (SUs) and activated by K + channel opening drugs. G protein and protein kinase such as PKA, PKC, PKG also participate in the regulation of these channels . K ATP channels play crucial roles in the secretion of insulin, preconditioning of cardiac myocytes and maintenance of blood vessel tone.