Unniappan Surajlal, Lin Xinwei, Cervini Laura, Rivier Jean, Kaiya Hiroyuki, Kangawa Kenji, Peter Richard E
Department of Biological Sciences, University of Alberta, Edmonton, Canada.
Endocrinology. 2002 Oct;143(10):4143-6. doi: 10.1210/en.2002-220644.
Complementary deoxyribonucleic acid (cDNA) encoding goldfish preproghrelin was identified using rapid amplification of the cDNA ends (RACE) and reverse transcription (RT)-polymerase chain reaction (PCR). The 490 bp cDNA encodes a 103 amino acid preproghrelin which has a 26 amino acid signal region, 19 amino acid mature peptide and a 55 amino acid C-terminal peptide region. The mature peptide region of goldfish ghrelin has two putative cleavage sites and amidation signals (GRR); one after 12 amino acids and the other after 19 amino acids. The serine (S) in the second amino acid position in the "active core" of ghrelin is substituted with threonine (T). The goldfish ghrelin gene has four exons and three short introns and resembles the human ghrelin gene. Ghrelin messenger RNA (mRNA) expression was detected in the brain, pituitary, intestine, liver, spleen and gill by RT-PCR followed by Southern blot analysis, and in the intestine by Northern blot. Intracerebroventricular (ICV) injection of n-octanoylated goldfish ghrelin (1-19) stimulates food intake in goldfish.
利用cDNA末端快速扩增技术（RACE）和逆转录（RT）-聚合酶链反应（PCR），鉴定出了编码金鱼前胃动素原的互补脱氧核糖核酸（cDNA）。490bp的cDNA编码一种含103个氨基酸的前胃动素原，其具有一个含26个氨基酸的信号区域、一个含19个氨基酸的成熟肽和一个含55个氨基酸的C末端肽区域。金鱼胃动素的成熟肽区域有两个假定的切割位点和酰胺化信号（GRR）；一个在12个氨基酸之后，另一个在19个氨基酸之后。胃动素“活性核心”中第二个氨基酸位置的丝氨酸（S）被苏氨酸（T）取代。金鱼胃动素基因有四个外显子和三个短内含子，与人胃动素基因相似。通过RT-PCR随后进行Southern印迹分析，在脑、垂体、肠、肝、脾和鳃中检测到胃动素信使核糖核酸（mRNA）表达，通过Northern印迹在肠中检测到该表达。脑室内（ICV）注射正辛酰化金鱼胃动素（1-19）可刺激金鱼的食物摄入。
