期刊
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
卷 97, 期 10, 页码 5651-5656出版社
NATL ACAD SCIENCES
DOI: 10.1073/pnas.080572297
关键词
-
Inwardly rectifying potassium (K(+)) channels gated by G proteins (Kir3.x family) are widely distributed in neuronal, atrial, and endocrine tissues and play key roles in generating late inhibitory postsynaptic potentials, slowing the heart rate and modulating hormone release. They are directly activated by G(beta gamma) subunits released from G protein heterotrimers of the G(i/o) family upon appropriate receptor stimulation. Here we examine the role of isoforms of pertussis toxin (PTx)-sensitive G protein alpha subunits (G(i alpha 1-3) and G(o alpha A)) in mediating coupling between Various receptor systems (A(1), alpha(2A) D(2S) M(4), GABA(B)1a+2, and GABA(B)1b+2) and the cloned counterpart of the neuronal channel (Kir3.1+3.2A). The expression of mutant PTx-resistant G(i/o alpha) subunits in PTx-treated HEK293 cells stably expressing Kir3.1+3.2A allows us to selectively investigate that coupling. We find that, for those receptors (A(1), alpha(2A)) known to interact with all isoforms, G(i alpha 1-3) and G(o alpha A) can all support a significant degree of coupling to Kir3.1+3.2A. The Mg receptor appears to preferentially couple to G(i alpha 2) while another group of receptors (D(2S), GABA(B)1a+2, GABA(B)1b+2) activates the channel predominantly through Cp, liberated from G(oA) heterotrimers. Interestingly, we have also found a distinct difference in C protein coupling between the two splice variants of GABA(B)1. Our data reveal selective pathways of receptor activation through different G(i/o alpha) isoforms for stimulation of the G protein-gated inwardly rectifying K(+) channel.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据