Gondo N, Ono K, Mannen K, Yatani A, Green S A, Arita M
Department of Physiology, Oita Medical University, Hasama, Japan.
FEBS Lett. 1998 Feb 13;423(1):86-92. doi: 10.1016/s0014-5793(98)00070-2.
Formation of single channel subconductance is one of the unique characteristics of the L-type Ca2+ channel. Although alpha1 subunit exhibits a primary function of the channel, it remains uncertain whether alpha1 subunit alone is able to produce subconductance. We tested this by studying single channel currents of cloned cardiac alpha1 subunit expressed in Chinese hamster fibroblast cells, with/without coexpression of cardiac beta subunit. The alpha1 subunit exhibited four distinct levels of conductance (22.7, 14.3, 6.2 and 3.2 pS). Coexpression of beta subunit significantly increased the number of openings in all four levels of conductance without changing the conductance values.
单通道亚电导的形成是L型钙通道的独特特征之一。尽管α1亚基表现出通道的主要功能，但仅α1亚基是否能够产生亚电导仍不确定。我们通过研究在中国仓鼠成纤维细胞中表达的克隆心脏α1亚基的单通道电流来测试这一点，该细胞有/无心脏β亚基的共表达。α1亚基表现出四种不同水平的电导（22.7、14.3、6.2和3.2 pS）。β亚基的共表达显著增加了所有四个电导水平的开放次数，而不改变电导值。
