Tang C Y, Schulteis C T, Jiménez R M, Papazian D M
Department of Physiology, UCLA School of Medicine 90095-1751, USA.
Biophys J. 1998 Sep;75(3):1263-70. doi: 10.1016/S0006-3495(98)74046-9.
Members of different voltage-gated K+ channel subfamilies usually do not form heteromultimers. However, coassembly between Shaker and ether-à-go-go (eag) subunits, members of two distinct K+ channel subfamilies, was suggested by genetic and functional studies (Zhong and Wu. 1991. Science. 252: 1562-1564; Chen, M.-L., T. Hoshi, and C.-F. Wu. 1996. Neuron. 17:535-542). We investigated whether Shaker and eag form heteromultimers in Xenopus laevis oocytes using electrophysiological and biochemical approaches. Coexpression of Shaker and eag subunits produced K+ currents that were virtually identical to the sum of separate Shaker and eag currents, with no change in the kinetics of Shaker inactivation. According to the results of dominant negative and reciprocal coimmunoprecipitation experiments, the Shaker and eag proteins do not interact. We conclude that Shaker and eag do not coassemble to form heteromultimers in Xenopus oocytes.
不同电压门控钾离子通道亚家族的成员通常不会形成异源多聚体。然而，遗传和功能研究表明，两个不同钾离子通道亚家族的成员，即Shaker和去极化激活延迟整流钾离子通道（eag）亚基之间会共同组装（钟和吴，1991年，《科学》，252卷：1562 - 1564页；陈，M.-L.，T. 星野，和C.-F. 吴，1996年，《神经元》，17卷：535 - 542页）。我们使用电生理学和生物化学方法研究了Shaker和eag在非洲爪蟾卵母细胞中是否形成异源多聚体。Shaker和eag亚基的共表达产生的钾离子电流实际上与单独的Shaker和eag电流之和相同，Shaker失活的动力学没有变化。根据显性负性和相互免疫共沉淀实验的结果，Shaker和eag蛋白不相互作用。我们得出结论，在非洲爪蟾卵母细胞中，Shaker和eag不会共同组装形成异源多聚体。
