Characterization of the chicken galanin type I receptor (GalR1) and a novel GalR1-like receptor (GalR1-L)
Characterization of the chicken galanin type I receptor (GalR1) and a novel GalR1-like receptor (GalR1-L)
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鸡甘丙肽 I 型受体 (GalR1) 和新型 GalR1 样受体 (GalR1-L) 的表征
DOI：
10.1016/j.ygcen.2010.10.011
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发表时间：
2011-01-15
影响因子：
2.7
通讯作者：
Leung, Frederick C.
中科院分区：
文献类型：
--
作者：
Ho, John Chi Wang;Kwok, Amy Ho Yan;Leung, Frederick C.
甘丙肽是一种多功能神经肽，广泛分布于哺乳动物中枢神经系统和周围组织中。它通过与3种已知的G蛋白偶联受体(GPCR)相互作用发挥多种生理功能，即Galanin I、II和III(GalR1、2和3)受体，这些受体仅在哺乳动物中被发现。在本研究中，我们克隆并鉴定了鸡甘丙素I型受体(GalR1)和一个与鸡GalR1有较高同源性的新的甘丙素受体，命名为甘丙素型L样受体(GalR1-L)。分别从鸡脑和小肠组织中克隆了鸡GalR1和GalR1-L的全长cDNA。前者编码357个氨基酸的蛋白质，与哺乳动物的氨基酸序列同源性为84-86%，而后者编码的363个氨基酸的蛋白质与哺乳动物GalR1的同源性相对较低(55-56%)。采用逆转录聚合酶链式反应(RT-PCR)方法，检测了这两种受体在成年鸡组织中的表达。两种受体均广泛分布于脑、小肠、肾、卵巢、胰腺、垂体和脾等组织。有趣的是，cGalR1在鸡输卵管的不同部位都有表达，而cGalR1-L的表达仅限于阴道。利用pGL3-Cre荧光素酶报告系统，鸡甘丙素多肽(1-29)通过cAMP介导的信号通路抑制中国仓鼠卵巢(CHO)细胞的基础荧光素酶活性和Forsklin刺激的荧光素酶活性，并呈剂量依赖关系，从而提示这两种受体与G(I)蛋白的功能偶联。综上所述，鸡GalR1和GalR1-L的特征为更好地理解Galanin在禽类中的生理作用提供了基础。(C)2010年，由爱思唯尔公司出版。
Galanin is a multi-functional neuropeptide that is widely distributed in the mammalian central nervous system and peripheral tissues. It exerts multiple physiological functions through interaction with 3 known G protein-coupled receptors (GPCR), namely galanin type I, II and III (GalR1,2 and 3) receptors, which have only been identified in mammals. In this study, we reported the cloning and characterization of chicken galanin type I receptor (GalR1) and a novel galanin receptor with considerable homology to chicken GalR1, which herein designated as galanin type l-like receptor (GalR1-L). Chicken GalR1 and GalR1-L full-length cDNAs were cloned from chicken brain and small intestine tissue, respectively. The former encodes a protein of 357 amino acids that shares 84-86% amino acid sequence identities with its mammalian counterparts, whereas the latter encodes a 363-amino acid protein with comparatively lower identities (55-56%) to the mammalian GalR1. Using reverse transcription (RT)-PCR assays, we examined the expression of both receptors in adult chicken tissues. Both receptors were found to be widely distributed in the tissues examined, including brain, small intestine, kidney, ovary, pancreas, pituitary and spleen. Interestingly, cGalR1 expression was detected in different regions of chicken oviduct, while cGalR1-L expression was restricted to the vagina. Using a pGL3-CRE luciferase reporter system, chicken galanin peptide (1-29) was demonstrated to inhibit both basal and forskolin-stimulated luciferase activities, in dose-dependent manners, through the cAMP-mediated signaling pathway in Chinese hamster ovary (CHO) cells expressing either cGalR1 or cGalR1-L, thus suggesting the functional couplings of both receptors to G(i) proteins. Together, the characterization of chicken GalR1 and GalR1-L provides a better understanding of the physiological roles of galanin in avian species. (C) 2010 Published by Elsevier Inc.