Structural Basis for Receptor Activity-Modifying Protein-Dependent Selective Peptide Recognition by a G Protein-Coupled Receptor.
Structural Basis for Receptor Activity-Modifying Protein-Dependent Selective Peptide Recognition by a G Protein-Coupled Receptor.
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DOI：
10.1016/j.molcel.2015.04.018
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发表时间：
2015-06-18
期刊：
影响因子：
16
通讯作者：
Pioszak AA
中科院分区：
文献类型：
--
作者：
Booe JM;Walker CS;Barwell J;Kuteyi G;Simms J;Jamaluddin MA;Warner ML;Bill RM;Harris PW;Brimble MA;Poyner DR;Hay DL;Pioszak AA
受体活性修饰蛋白（RAMP1-3）与G蛋白偶联受体（GPCR）降钙素受体样受体（CLR）的关联使得降钙素基因相关肽（CGRP）和肾上腺髓质素（AM）在心血管和淋巴系统中具有不同的功能。肽如何选择性地结合GPCR:RAMP复合物是未知的。我们报道了CGRP类似物结合的CLR:RAMP1和am结合的CLR:RAMP2细胞外结构域异二聚体的晶体结构，分别为2.5和1.8 Å分辨率。这些肽同样占据CLR上的共享结合位点，其构象的特征是靠近其C末端的β-旋结构，而不是与相关gpcr结合的肽常见的α-螺旋结构。RAMPs增加了与可变c末端肽残基有明显接触的结合位点，并引发了细微不同的CLR构象。结构和伴随的药理学数据揭示了一类辅助膜蛋白如何调节GPCR的配体结合，并可能为靶向CLR:RAMP复合物的药物开发提供信息。晶体结构揭示了CGRP和AM肽如何结合其异二聚体受体CGRP和AM在与RAMPs接触最小的CLR上占据一个共享的结合位点，通过诱变证实了细胞中完整受体的肽结合模式，肽的选择性来自于与RAMP特异性接触和对CLR的细微改变。Booe等人报道了两个晶体结构，揭示了GPCR CLR对CGRP和AM肽的选择性是如何被RAMP蛋白调节的。这些肽类似地占据CLR上的共享结合位点。RAMPs通过与肽的不同接触增加了结合位点，并微妙地改变了CLR。
Association of receptor activity-modifying proteins (RAMP1-3) with the G protein-coupled receptor (GPCR) calcitonin receptor-like receptor (CLR) enables selective recognition of the peptides calcitonin gene-related peptide (CGRP) and adrenomedullin (AM) that have diverse functions in the cardiovascular and lymphatic systems. How peptides selectively bind GPCR:RAMP complexes is unknown. We report crystal structures of CGRP analog-bound CLR:RAMP1 and AM-bound CLR:RAMP2 extracellular domain heterodimers at 2.5 and 1.8 Å resolutions, respectively. The peptides similarly occupy a shared binding site on CLR with conformations characterized by a β-turn structure near their C termini rather than the α-helical structure common to peptides that bind related GPCRs. The RAMPs augment the binding site with distinct contacts to the variable C-terminal peptide residues and elicit subtly different CLR conformations. The structures and accompanying pharmacology data reveal how a class of accessory membrane proteins modulate ligand binding of a GPCR and may inform drug development targeting CLR:RAMP complexes. Crystal structures reveal how CGRP and AM peptides bind their heterodimeric receptors CGRP and AM occupy a shared binding site on CLR with minimal contact to the RAMPs Peptide binding modes were confirmed for intact receptors in cells by mutagenesis Peptide selectivity arises from RAMP-specific contacts and subtle alteration of CLR Booe et al. report two crystal structures that reveal how selectivity of the GPCR CLR for CGRP and AM peptides is modulated by RAMP proteins. The peptides similarly occupy a shared binding site on CLR. RAMPs augment the binding site with distinct contacts to the peptides and subtly alter CLR.