Identification, Localization, and Function of a Novel Avian Hypothalamic Neuropeptide, 26RFa, and Its Cognate Receptor, G Protein-Coupled Receptor-103
Identification, Localization, and Function of a Novel Avian Hypothalamic Neuropeptide, 26RFa, and Its Cognate Receptor, G Protein-Coupled Receptor-103
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DOI：
10.1210/en.2009-1478
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发表时间：
2010-05-01
期刊：
影响因子：
4.8
通讯作者：
Tsutsui, Kazuyoshi
中科院分区：
文献类型：
--
作者：
Ukena, Kazuyoshi;Tachibana, Tetsuya;Tsutsui, Kazuyoshi
已在多种脊椎动物的下丘脑中鉴定出几种具有 C 末端 RFamide 序列的神经肽。然而，在 RFamide 肽组中，只有 LPXRFamide 肽（包括促性腺激素抑制激素）在鸟类大脑中得到了表征。在本研究中，我们寻找鸟类下丘脑中是否存在其他 RFamide 肽。我们在日本鹌鹑的下丘脑中鉴定出编码与 26RFa（也称为 QRFP）同源的 RFamide 肽的 cDNA。推导的鹌鹑26RFa前体由120个氨基酸残基组成，编码一个具有27个氨基酸的RFamide肽。该 RFamide 肽的 N 末端侧翼有二元氨基酸切割位点，C 末端侧翼有甘氨酸酰胺化信号。定量 RT-PCR 分析证明鹌鹑 26RFa mRNA 在间脑（包括下丘脑）中特异性表达。此外，质谱分析显示存在具有成熟26RFa质量的肽，表明该肽实际上是由间脑中的前体产生的。产生 26RFa 的细胞体位于大脑的下丘脑前核。合成的26RFa增加了用鸡G蛋白偶联受体GPR103转染的HEK293T细胞中的细胞内Ca(2+)浓度。肉鸡脑室内注射 26RFa 可刺激采食行为。这些数据为禽类下丘脑中存在肽 26RFa 提供了第一个证据，并表明该肽具有促进食欲的活性。 （内分泌学151：2255-2264，2010）
Several neuropeptides with the C-terminal RFamide sequence have been identified in the hypothalamus of a variety of vertebrates. Among the RFamide peptide groups, however, only LPXRFamide peptides, including gonadotropin-inhibitory hormone, have been characterized in the avian brain. In the present study, we sought for the presence of other RFamide peptides in the avian hypothalamus. We identified a cDNA encoding an RFamide peptide orthologous to 26RFa (also referred to as QRFP) in the hypothalamus of the Japanese quail. The deduced quail 26RFa precursor consisted of 120-amino-acid residues, encoding one RFamide peptide with 27 amino acids. This RFamide peptide was flanked at the N terminus by a dibasic amino acid cleavage site and at the C terminus by a glycine amidation signal. Quantitative RT-PCR analysis demonstrated specific expression of quail 26RFa mRNA in the diencephalon including the hypothalamus. Furthermore, mass spectrometry analysis revealed the presence of a peptide exhibiting the mass of mature 26RFa, indicating that the peptide is actually produced from the precursor in the diencephalon. 26RFa-producing cell bodies were localized in the anterior hypothalamic nucleus in the brain. Synthetic 26RFa increased intracellular Ca(2+) concentration in HEK293T cells transfected with the chicken G protein-coupled receptor GPR103. Intracerebroventricular injection of 26RFa in broiler chicks stimulated feeding behavior. These data provide the first evidence for the occurrence of the peptide 26RFa in the avian hypothalamus and indicate that this peptide exerts orexigenic activity. (Endocrinology 151: 2255-2264, 2010)