Receptor Activity-modifying Proteins 2 and 3 Generate Adrenomedullin Receptor Subtypes with Distinct Molecular Properties.
Receptor Activity-modifying Proteins 2 and 3 Generate Adrenomedullin Receptor Subtypes with Distinct Molecular Properties.
复制标题
DOI：
10.1074/jbc.m115.688218
复制
发表时间：
2016-05-27
期刊：
影响因子：
--
通讯作者：
Hay DL
中科院分区：
文献类型：
--
作者：
Watkins HA;Chakravarthy M;Abhayawardana RS;Gingell JJ;Garelja M;Pardamwar M;McElhinney JM;Lathbridge A;Constantine A;Harris PW;Yuen TY;Brimble MA;Barwell J;Poyner DR;Woolley MJ;Conner AC;Pioszak AA;Reynolds CA;Hay DL
肾上腺髓质素（AM）是一种在血管系统中具有多种作用的肽类激素。AM通过AM 1和AM 2受体发出信号，AM 1和AM 2受体分别由G蛋白偶联受体、降钙素受体样受体（CGRP）和受体活性修饰蛋白2和3（RAMP 2和RAMP 3）的专性异源二聚化形成。这些不同的CLR-RAMP相互作用产生离散的受体药理学和生理学效应。靶向单个AM受体的治疗剂的有效设计取决于对RAMP对RAMP作用的分子细节的理解。为了了解RAMP 2和-3对AM受体的cAMP亚基的激活和构象的作用，我们突变了AM受体激活的关键区域cAMP的质膜区域中的68个氨基酸，并确定了对cAMP信号传导的影响。16个突变在AM 1和AM 2受体之间具有不同的作用。伴随着这一点，独立的分子建模的全长AM结合的AM 1和AM 2受体预测的差异，在结合口袋和差异的静电电位的两个AM受体。药物敏感性分析表明，独特的功能，可用于开发选择性的小分子配体的每个受体。RAMP 2或RAMP 3与RAMP 3的相互作用可能通过变构机制诱导质膜区域的构象变化，产生不同的结合口袋。这些亚型特异性差异对设计针对特定AM受体的治疗药物和了解辅助蛋白影响G蛋白偶联受体功能的机制具有意义。
Adrenomedullin (AM) is a peptide hormone with numerous effects in the vascular systems. AM signals through the AM1 and AM2 receptors formed by the obligate heterodimerization of a G protein-coupled receptor, the calcitonin receptor-like receptor (CLR), and receptor activity-modifying proteins 2 and 3 (RAMP2 and RAMP3), respectively. These different CLR-RAMP interactions yield discrete receptor pharmacology and physiological effects. The effective design of therapeutics that target the individual AM receptors is dependent on understanding the molecular details of the effects of RAMPs on CLR. To understand the role of RAMP2 and -3 on the activation and conformation of the CLR subunit of AM receptors, we mutated 68 individual amino acids in the juxtamembrane region of CLR, a key region for activation of AM receptors, and determined the effects on cAMP signaling. Sixteen CLR mutations had differential effects between the AM1 and AM2 receptors. Accompanying this, independent molecular modeling of the full-length AM-bound AM1 and AM2 receptors predicted differences in the binding pocket and differences in the electrostatic potential of the two AM receptors. Druggability analysis indicated unique features that could be used to develop selective small molecule ligands for each receptor. The interaction of RAMP2 or RAMP3 with CLR induces conformational variation in the juxtamembrane region, yielding distinct binding pockets, probably via an allosteric mechanism. These subtype-specific differences have implications for the design of therapeutics aimed at specific AM receptors and for understanding the mechanisms by which accessory proteins affect G protein-coupled receptor function.