Identification of a neuropeptide modified with bromine as an endogenous ligand for GPR7
Identification of a neuropeptide modified with bromine as an endogenous ligand for GPR7
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DOI：
10.1074/jbc.m205883200
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发表时间：
2002-09-13
影响因子：
4.8
通讯作者：
Fujino, M
中科院分区：
文献类型：
--
作者：
Fujii, R;Yoshida, H;Fujino, M
我们在Celera数据库中分离到一个新基因，发现它编码G蛋白偶联受体GPR7(O‘Dowd，B.F.，Scheideler，M.A.，Nguyen，T.，Cheng，R.，Rasmussen，J.S.，Marchese，A.，Zastawny，R.，Heng，H.，Tsui，L.C.，Shii，X.，Asa，S.，Puy，L.和George，S.R.(1995)基因组学28，84-91；李东凯，阮氏，T.，Porter，C.A.，Cheng，R.，George，S.R.和O‘Dowd，B.F.(1999)Mol.脑部研究报告71，96-103)。在大鼠的淋巴器官、中枢神经系统、乳腺和子宫等组织中检测到该基因的表达。GPR7mRNA主要在中枢神经系统和子宫中表达。原位杂交显示GPR7配体编码基因在大鼠下丘脑和海马区均有表达。为了确定内源性GPR7配体的分子结构，我们从牛下丘脑组织提取物中纯化了它，基于对表达GPR7的细胞产生cAMP的抑制活性。通过结构分析，我们发现纯化的内源配体是一个由29个氨基酸残基组成的多肽，并且它是唯一用溴修饰的。我们随后确定了N-末端色氨酸中吲哚部分的C-6位置是溴化的。我们认为这是首次报道用溴修饰的神经肽，因此将其命名为神经肽B。在体外实验中，溴化不影响神经肽B与受体的结合。
We isolated a novel gene in a search of the Celera data base and found that it encoded a peptidic ligand for a G protein-coupled receptor, GPR7 (O'Dowd, B. F., Scheideler, M. A., Nguyen, T., Cheng, R., Rasmussen, J. S., Marchese, A., Zastawny, R., Heng, H. H., Tsui, L. C., Shi, X., Asa, S., Puy, L., and George, S. R. (1995) Genomics 28,84-91; Lee, D. K., Nguyen, T., Porter, C. A., Cheng, R., George, S. R., and O'Dowd, B. F. (1999) Mol. Brain Res. 71, 96-103). The expression of this gene was detected in various tissues in rats, including the lymphoid organs, central nervous system, mammary glands, and uterus. GPR7 mRNA was mainly detected in the central nervous system and uterus. In situ hybridization showed that the gene encoding the GPR7 ligand was expressed in the hypothalamus and hippocampus of rats. To determine the molecular structure of the endogenous GPR7 ligand, we purified it from bovine hypothalamic tissue extracts on the basis of cAMP production-inhibitory activity to cells expressing GPR7. Through structural analyses, we found that the purified endogenous ligand was a peptide with 29 amino acid residues and that it was uniquely modified with bromine. We subsequently determined that the C-6 position of the indole moiety in the N-terminal Trp was brominated. We believe this is the first report on a neuropeptide modified with bromine and have hence named it neuropeptide B. In in vitro assays, bromination did not influence the binding of neuropeptide B to the receptor.