HETEROLOGOUS MULTIMERIC ASSEMBLY IS ESSENTIAL FOR K+ CHANNEL ACTIVITY OF NEURONAL AND CARDIAC G-PROTEIN-ACTIVATED INWARD RECTIFIERS
HETEROLOGOUS MULTIMERIC ASSEMBLY IS ESSENTIAL FOR K+ CHANNEL ACTIVITY OF NEURONAL AND CARDIAC G-PROTEIN-ACTIVATED INWARD RECTIFIERS
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DOI：
10.1006/bbrc.1995.2019
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发表时间：
1995-07-17
影响因子：
3.1
通讯作者：
BARHANIN, J
中科院分区：
文献类型：
--
作者：
DUPRAT, F;LESAGE, F;BARHANIN, J
G蛋白激活的内向整流钾通道家族目前包括至少3个被称为GIRK 1、GIRK 2和GIRK 3的克隆成员。GIRK通道的一个密切的结构母体最近被描述为ATP敏感的K+通道。本文表明，非洲爪蟾表达的这个新的通道，我们称之为GIRK 4不产生ATP可激活的活性与药理学激活吡那地尔如前所述，而是G蛋白激活内向整流。虽然单个亚基的卵母细胞表达不常见且强度相对适中，但GIRK 1，2、GIRK 1，4和GIRK 2，4混合物的表达导致K+通道的常规和稳健表达，表明异源亚基组装是活性所必需的。GIRK 1，2、GIRK 1，4和GIRK 2，4通道的活性需要Am的存在，Am在细胞质表面充当激活剂，并被β-γ亚基进一步激活。(C)出版社：Academic Press
The family of G-protein-activated inward-rectifiers K+ channels presently comprise at least 3 cloned members called GIRK1, GIRK2 and GIRK3. A close structural parent of GIRK channels has recently been described as being an ATP-sensitive K+ channel. This paper shows that Xenopus expression of this new channel that we call GIRK4 does not produce an ATP-inhibitable activity with a pharmacological activation by pinacidil as previously described but instead a G-protein activated inward-rectifier. While oocyte expression of single subunits is infrequent and relatively modest in intensity, expression of GIRK1,2, GIRK1,4 and GIRK2,4 mixtures leads to routine and robust expression of K+ channels indicating that heterologous subunit assembly is necessary for activity. Activity of GIRK1,2 GIRK1,4 and GIRK2,4 channels required the presence of Am acting as an activator at the cytoplasmic face and is further activated by the beta gamma subunits. (C) 1995 Academic Press, Inc.