Cloning, characterization and distribution of receptor activity central nervous system modifying proteins in the rat
Cloning, characterization and distribution of receptor activity central nervous system modifying proteins in the rat
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DOI：
10.1046/j.0953-816x.2001.01688.x
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发表时间：
2001-08-01
影响因子：
3.4
通讯作者：
Hill, RG
中科院分区：
文献类型：
--
作者：
Oliver, KR;Kane, SA;Hill, RG
降钙素基因相关肽（CGRP）、肾上腺髓质素（ADM）、胰淀素（amylin）和降钙素（CT）是结构和功能上相关的神经肽。最近的研究表明，CGRP和ADM的分子药理学是由三种受体活性修饰蛋白（RAMP）之一与降钙素受体样受体（CRLR）的共表达决定的。此外，RAMP蛋白还显示出支配降钙素受体的药理学，降钙素受体与RAMP 1或RAMP 3结合，以高亲和力结合胰淀素。在这项研究中，我们克隆了大鼠RAMP家族和大鼠CGRP和ADM受体的药理学特征。大鼠RAMP 1、RAMP 2和RAMP 3与人RAMP 1、RAMP 2和RAMP 3同源性分别为72%、69%和85%。正如预期的那样，CRLR-RAMP 1共表达赋予了对CGRP的敏感性，而RAMP 2或RAMP 3与CRLR的结合赋予了高亲和力的ADM结合。使用特定的寡核苷酸，我们已经确定了RAMP 1，RAMP 2和RAMP 3的mRNA在大鼠中枢神经系统的表达，通过原位杂交。RAMP mRNA的定位是异质性的。RAMP 1 mRNA主要表达于皮层、尾壳核和嗅结节; RAMP 2 mRNA在下丘脑中表达最丰富; RAMP 3仅在丘脑核团中表达。有趣的是，在特定的大脑区域，只有一个单一的RAMP mRNA往往被检测到，这表明在表达的相互排斥性。这些数据允许预测每个RAMP蛋白可以在细胞水平上与其伴侣G蛋白偶联受体异二聚化的位置，从而推进目前对CGRP、ADM、胰淀素和CT的细胞作用位点的理解。此外，这些定位数据表明，RAMP家族可能与其他尚未鉴定的神经递质受体相关并改变其行为。
Calcitonin gene-related peptide (CGRP), adrenomedullin (ADM), amylin and calcitonin (CT) are structurally and functionally related neuropeptides. It has recently been shown that the molecular pharmacology of CGRP and ADM is determined by coexpression of one of three receptor activity-modifying proteins (RAMPs) with calcitonin receptor-like receptor (CRLR). Furthermore, RAMP proteins have also been shown to govern the pharmacology of the calcitonin receptor, which in association with RAMP1 or RAMP3, binds amylin with high affinity. In this study, we have cloned the rat RAMP family and characterized the pharmacology of rat CGRP and ADM receptors. Rat RAMP1, RAMP2 and RAMP3 shared 72%, 69% and 85% homology with their respective human homologues. As expected CRLR-RAMP1 coexpression conferred sensitivity to CGRP, whilst association of RAMP2 or RAMP3 with CRLR conferred high affinity ADM binding. Using specific oligonucleotides we have determined the expression of RAMP1, RAMP2 and RAMP3 mRNAs in the rat central nervous system by in situ hybridization. The localization of RAMP mRNAs was heterogeneous. RAMP1 mRNA was predominantly expressed in cortex, caudate putamen and olfactory tubercles; RAMP2 mRNA was most abundant in hypothalamus; and RAMP3 was restrictively expressed in thalamic nuclei. Interestingly, in specific brain areas only a single RAMP mRNA was often detected, suggesting mutual exclusivity in expression. These data allow predictions to be made of where each RAMP protein may heterodimerize with its partner G-protein-coupled receptor(s) at the cellular level and consequently advance current understanding of cellular sites of action of CGRP, ADM, amylin and CT. Furthermore, these localization data suggest that the RAMP family may associate and modify the behaviour of other, as yet unidentified neurotransmitter receptors.