Department of Animal Science, Faculty of Applied Life Science, Nippon Veterinary and Life Science University, Musashino, Tokyo 180-8602, Japan.
Gen Comp Endocrinol. 2011 Mar 1;171(1):33-8. doi: 10.1016/j.ygcen.2010.12.021. Epub 2011 Jan 1.
Neurotensin, a tridecapeptide, is distributed in a wide range of tissues and exhibits multiple functions through its receptors. Hitherto molecular characterization of the neurotensin receptor has been reported in mammalian, amphibian, and fish species but not in avian species. In this study, we cloned the cDNA encoding chicken neurotensin receptor from the duodenum and characterized its primary structure, biological activity and distribution in the gastrointestinal tract. The cDNA encoded a protein consisting of 399 amino acids that had significant overall sequence homology to other vertebrate neurotensin receptor 1 with higher extent in the seven transmembrane domains. Chicken neurotensin increased intracellular Ca(2+) concentrations in human embryonic kidney 293 cells transiently expressing the chicken neurotensin receptor 1. Real-time PCR analysis showed that chicken neurotensin receptor 1 mRNA is expressed throughout the gastrointestinal tract with markedly higher level in the colon/rectum. These results indicate that the chicken neurotensin receptor 1 is involved in gastrointestinal functions through an intracellular signaling pathway accompanied by an increase in Ca(2+) levels.
神经降压素是一种十肽，分布于广泛的组织中，并通过其受体发挥多种功能。迄今为止，已在哺乳动物、两栖动物和鱼类物种中报道了神经降压素受体的分子特征，但在鸟类物种中尚未报道。在这项研究中，我们从十二指肠中克隆了编码鸡神经降压素受体的 cDNA，并对其一级结构、生物活性和在胃肠道中的分布进行了表征。该 cDNA 编码的蛋白质由 399 个氨基酸组成，与其他脊椎动物神经降压素受体 1 具有显著的整体序列同源性，在七个跨膜结构域中更为明显。鸡神经降压素增加了瞬时表达鸡神经降压素受体 1 的人胚肾 293 细胞内的 Ca(2+)浓度。实时 PCR 分析显示，鸡神经降压素受体 1 mRNA 表达于整个胃肠道，在结肠/直肠中表达水平更高。这些结果表明，鸡神经降压素受体 1 通过伴随 Ca(2+)水平升高的细胞内信号通路参与胃肠道功能。
