The highly conserved negatively charged Glu141 and Asp145 of the G-protein-coupled receptor RXFP3 interact with the highly conserved positively charged arginine residues of relaxin-3
The highly conserved negatively charged Glu141 and Asp145 of the G-protein-coupled receptor RXFP3 interact with the highly conserved positively charged arginine residues of relaxin-3
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G 蛋白偶联受体 RXFP3 的高度保守的带负电荷的 Glu141 和 Asp145 与relaxin-3 的高度保守的带正电荷的精氨酸残基相互作用
DOI：
10.1007/s00726-014-1705-3
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发表时间：
2014-03
期刊：
影响因子：
3.5
通讯作者：
Guo, Zhan-Yun
中科院分区：
文献类型：
--
作者：
Shao, Xiao-Xia;Liu, Ya-Li;Xu, Zeng-Guang;Guo, Zhan-Yun
relaxin -3是一种新发现的胰岛素/松弛素超家族肽，通过激活其同源的g蛋白偶联受体RXFP3，在调节食物摄入和应激反应中发挥作用。松弛素-3有三个高度保守的精氨酸残基：B12Arg、B16Arg和B26Arg。我们推测这些带正电的精氨酸可能与RXFP3的某些带负电的残基相互作用。为了验证这一假设，我们首先用精氨酸分别取代RXFP3胞外结构域的负电荷残基。受体激活实验表明，精氨酸替代Glu141或Asp145，尤其是Glu141，显著降低了RXFP3对野生型松弛素-3的敏感性。相反，精氨酸替代其他带负电荷的胞外残基的作用很小。因此，我们推断位于第二跨膜结构域胞外末端的Glu141和Asp145在RXFP3与松弛素-3的相互作用中发挥了关键作用。为了鉴定与RXFP3带负电荷的EXXXD基序相互作用的配体残基，我们分别用带负电荷的谷氨酸或天冬氨酸取代了松弛素-3的三个保守精氨酸。突变体松弛素-3保留了天然结构，但对野生型RXFP3的结合和激活能力明显降低。突变体relaxin-3s对突变体RXFP3s的代偿作用表明，在配体-受体相互作用中，RXFP3的Glu141与relaxin-3的B26Arg相互作用，而RXFP3的Asp145与relaxin-3的B12Arg和B16Arg相互作用。基于这些结果，我们提出了一个松弛素-3/RXFP3相互作用模型，为松弛素家族多肽与其受体的相互作用机制提供了新的思路。
Relaxin-3 is a newly identified insulin/relaxin superfamily peptide that plays a putative role in the regulation of food intake and stress response by activating its cognate G-protein-coupled receptor RXFP3. Relaxin-3 has three highly conserved arginine residues, B12Arg, B16Arg and B26Arg. We speculated that these positively charged arginines may interact with certain negatively charged residues of RXFP3. To test this hypothesis, we first replaced the negatively charged residues in the extracellular domain of RXFP3 with arginine, respectively. Receptor activation assays showed that arginine replacement of Glu141 or Asp145, especially Glu141, significantly decreased the sensitivity of RXFP3 to wild-type relaxin-3. In contrast, arginine replacement of other negatively charged extracellular residues had little effect. Thus, we deduced that Glu141 and Asp145, locating at the extracellular end of the second transmembrane domain, played a critical role in the interaction of RXFP3 with relaxin-3. To identify the ligand residues interacting with the negatively charged EXXXD motif of RXFP3, we replaced the three conserved arginines of relaxin-3 with negatively charged glutamate or aspartate, respectively. The mutant relaxin-3s retained the native structure, but their binding and activation potencies towards wild-type RXFP3 were decreased significantly. The compensatory effects of the mutant relaxin-3s towards mutant RXFP3s suggested two probable interaction pairs during ligand–receptor interaction: Glu141 of RXFP3 interacted with B26Arg of relaxin-3, meanwhile Asp145 of RXFP3 interacted with both B12Arg and B16Arg of relaxin-3. Based on these results, we proposed a relaxin-3/RXFP3 interaction model that shed new light on the interaction mechanism of the relaxin family peptides with their receptors.
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影响因子：
3
作者：
Watanabe Y;Tsujimura A;Takao K;Nishi K;Ito Y;Yasuhara Y;Nakatomi Y;Yokoyama C;Fukui K;Miyakawa T;Tanaka M
通讯作者：
Tanaka M
影响因子：
3.5
作者：
Craig M. Smith;I. T. Hosken;Steve W. Sutton;Andrew J. Lawrence;A. L. Gundlach
通讯作者：
Craig M. Smith;I. T. Hosken;Steve W. Sutton;Andrew J. Lawrence;A. L. Gundlach
影响因子：
4.8
作者：
Liu, CL;Chen, JC;Lovenberg, TW
通讯作者：
Lovenberg, TW
影响因子：
--
作者：
McGowan, B. M.;Stanley, S. A.;Bloom, S. R.
通讯作者：
Bloom, S. R.
影响因子：
3
作者：
Hossain, Mohammed Akhter;Bathgate, Ross A. D.;Wade, John D.
通讯作者：
Wade, John D.