期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1990
卷号：87
期号：22
页码：8903-8907
DOI：10.1073/pnas.87.22.8903
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Two members of the Shaker K+ channel family designated ShA2 and ShD2 were characterized in the Xenopus oocyte expression system. The predicted amino acid sequences of ShA2 and ShD2 differ only in the amino terminus, which is located intracellularly according to the present topological model of K+ channels. The differing amino termini have profound effects on the electrophysiological and pharmacological properties of the K+ channel. Most markedly, the nature of the amino terminus determines whether the K+ channel mediates rapidly inactivating or noninactivating K+ currents. It also affects the 4-aminopyridine, tetraethylammonium, and charybdotoxin sensitivities of the K+ channels. These results suggest that the amino terminus of Shaker proteins affects K+ channel structures on both sides of the membrane.
