Incorporation of Galpha(z)-specific sequence at the carboxyl terminus increases the promiscuity of galpha(16) toward G(i)-coupled receptors.
Incorporation of Galpha(z)-specific sequence at the carboxyl terminus increases the promiscuity of galpha(16) toward G(i)-coupled receptors.
复制标题
在羧基末端掺入 Galpha(z) 特异性序列会增加 galpha(16) 与 G(i) 偶联受体的混杂性。
作者：
Sejal M. Mody;M. K. Ho;S. Joshi;Yung Hou Wong
虽然G（16）的混杂性质允许其与许多G蛋白偶联受体相互作用，但一些G（i）连接的受体不能通过G（16）激活磷脂酶C。构建了一系列Ga（16）和Ga（z）之间的嵌合体，并测定了它们介导受体诱导的磷脂酶C刺激的能力。两个在C末端含有25或44个G α（z）特异性序列的G α（16/z）嵌合体（命名为16 z25和16 z44）能够对14种不同的G（i）偶联受体产生反应，包括那些不能与G α（16）（褪黑激素Mel 1c）结合或弱激活G α（16）（微阿片和1型生长抑素）的受体。激动剂诱导的磷脂酶C刺激作用，16 z44比Galalpha更有效地介导（最大值更高，EC（50）值更低）（16）。16 z25和16 z44也与G（s）-和G（q）-连接的受体偶联。在G α（16）的N末端掺入G α（z）序列并没有进一步增强嵌合体与G（i）偶联受体相互作用的能力。各种嵌合体的表达通过其组成型激活突变体的免疫检测和功能分析来验证。这些结果表明，将G α（z）的α 4/β 6和α 5区域并入G α（16）骨架中可以改善G（i）偶联受体的识别。具有与G（i）连接的受体相互作用的扩展能力的G α（16/z）嵌合体可用于将孤儿受体连接至磷脂酶C的刺激。
Although the promiscuous nature of G(16) allows it to interact with numerous G protein-coupled receptors, several G(i)-linked receptors are incapable of activating phospholipase C via G(16). A series of chimeras between Galpha(16) and Galpha(z) were constructed and assayed for their ability to mediate receptor-induced stimulation of phospholipase C. Two Galpha(16/z) chimeras harboring 25 or 44 Galpha(z)-specific sequences at their C termini (named 16z25 and 16z44) were capable of responding to 14 different G(i)-coupled receptors tested, including those that were either unable to associate with Galpha(16) (melatonin Mel1c) or activate Galpha(16) weakly (micro-opioid and type 1 somatostatin). Agonist-induced stimulation of phospholipase C was more efficiently mediated (higher maximal and lower EC(50) value) by 16z44 than by Galpha(16). Both 16z25 and 16z44 were also coupled to G(s)- and G(q)-linked receptors. Incorporation of Galpha(z) sequence at the N terminus of Galpha(16) did not further enhance the ability of the chimeras to interact with G(i)-coupled receptors. Expression of the various chimeras was verified by immunodetection and functional analysis of their constitutively activated mutants. These results show that the incorporation of alpha4/beta6 and alpha5 regions of Galpha(z) into a Galpha(16) backbone can improve the recognition of G(i)-coupled receptors. Galpha(16/z) chimeras with expanded capability to interact with G(i)-linked receptors may be used to link orphan receptors to the stimulation of phospholipase C.
登录
查看更多内容
DOI：
10.1016/s0021-9258(18)35680-1
发表时间：
1992-12
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Dianqing Wu;A. Katz;C. Lee;Melvin I. Simon
通讯作者：
Dianqing Wu;A. Katz;C. Lee;Melvin I. Simon
DOI：
10.1073/pnas.93.7.2827
发表时间：
1996-04
影响因子：
11.1
作者：
Xi Zhu;Lutz Birnbaumer
通讯作者：
Xi Zhu;Lutz Birnbaumer
GTPase 缺陷的 G α 16 的表达会抑制 Swiss 3T3 细胞的生长。
DOI：
--
发表时间：
1994
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Qian,NX;Russell,M;Buhl,AM;Johnson,GL
通讯作者：
Johnson,GL
G α 16 的多个区域有助于 C5a 受体激活的特异性。
DOI：
--
发表时间：
1995
期刊：
Molecular pharmacology.
影响因子：
--
作者：
Lee,CH;Katz,A;Simon,MI
通讯作者：
Simon,MI