Level of expression controls modes of gating of a K+ channel

FEBS Letters

Dascal, Nathan¹  Moran, Ofira¹  Schreibmayer, Wolfgang²  Weigl, Lukas²  Lotan, Ilana¹ 

[1] Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Ramat Aviv 69978, Israel;Institute of Medical Physics and Biophysics, Karl-Franzens University Graz, A-8010 Graz, Austria

关键词: Potassium channel;    cDNA expression;    Xenopus oocyte;    Single-channel analysis;    Inactivation kinetics;   

DOI  :  10.1016/0014-5793(92)80275-L

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Several distinct subfamilies of K⁺ channel genes have been discovered by molecular cloning, however, in some cases the structural differences among them do not account for the diversity of K⁺ current types, ranging from transient A-type to slowly inactivating delayed rectifier-type, as members within each subfamily have been shown to code for K⁺ channels of different inactivation kinetics and pharmacological properties. We show that a single K⁺ channel cDNA of the Shaker subfamily (ShH4) can express in Xenopus oocytes not only a transient A-type K⁺ current but also, upon increased level of expression, slowly inactivating K⁺ currents with markedly reduced sensitivity to tetraethylammonium. In correlation with the macroscopic currents there are single-channel gating modes ranging from the fast-inactivation mode which underlies the transient A-type current, to slow-inactivation modes characterized by bursts of longer openings, and corresponding to the slowly inactivating macroscopic currents.

【 授权许可】

Unknown