人心脏电压依赖性钙通道β(2a)亚基的克隆：α(2)/δ与β(2a)对α(1C)亚基膜表达的协同作用。

Cloning of the beta(2a) subunit of the voltage-dependent calcium channel from human heart: cooperative effect of alpha(2)/delta and beta(2a) on the membrane expression of the alpha(1C) subunit.

作者信息

Yamaguchi H, Okuda M, Mikala G, Fukasawa K, Varadi G

机构信息

Institute of Molecular Pharmacology, Department of Cell Biology, University of Cincinnati, College of Medicine, 231 Bethesda Avenue, Cincinnati, Ohio, 45267-0828, USA.

出版信息

Biochem Biophys Res Commun. 2000 Jan 7;267(1):156-63. doi: 10.1006/bbrc.1999.1926.

DOI:10.1006/bbrc.1999.1926

PMID:10623591

Abstract

Expression and membrane localization of an epitope-tagged human Ca(2+) channel alpha(1C) subunit were monitored in Xenopus oocytes by confocal microscopy and electrophysiological recording. When alpha(2)/delta and beta(2a) were separately coexpressed with the alpha(1C) subunit, assessment by confocal microscopy showed an 86 and 225% increase of the channel density, respectively. Simultaneous coexpression of alpha(2)/delta and beta(2a) subunits resulted in a cooperative (470%) increase. Electrophysiological measurements performed in parallel revealed that the current augmentation by the alpha(2)/delta subunit is totally attributable to an increase in channel density, whereas the beta(2a) subunit, in addition to increasing channel density, also facilitates channel opening.

摘要

通过共聚焦显微镜和电生理记录监测了表位标记的人Ca(2+)通道α(1C)亚基在非洲爪蟾卵母细胞中的表达和膜定位。当α(2)/δ和β(2a)分别与α(1C)亚基共表达时，共聚焦显微镜评估显示通道密度分别增加了86%和225%。α(2)/δ和β(2a)亚基同时共表达导致协同增加(470%)。同时进行的电生理测量表明，α(2)/δ亚基引起的电流增强完全归因于通道密度的增加，而β(2a)亚基除了增加通道密度外，还促进通道开放。