Hilario E, Lihrmann I, Vaudry H
Groupe de Recherche en Endocrinologie Moléculaire, URA CNRS 650, Unité Affiliée à l'INSERM, Université de Rouen, Mont-Saint-Aignan, France.
Biochem Biophys Res Commun. 1990 Dec 14;173(2):653-9. doi: 10.1016/s0006-291x(05)80085-3.
In the amphibian pars intermedia, secretion of proopiomelanocortin (POMC)-derived peptides is controlled by multiple factors including classical neurotransmitters and neuropeptides. To pursue questions concerning the regulation of POMC gene expression in Rana ridibunda, we have isolated and characterized a full-length cDNA for frog POMC. A cDNA clone isolated from a frog pituitary library contains an open-reading frame of 780-bp that predicts a 260 amino acid POMC protein. The structure of frog POMC demonstrates considerable amino acid sequence similarity with POMC from other species. In particular, the sequence of alpha-melanotropin (alpha-MSH) is identical in frog and all mammalian species studied so far, while adrenocorticotropin (ACTH) and beta-endorphin exhibit 79% and 84% homology with their human counterpart. Frog POMC contains only one potential asparagine-linked N-glycosylation signal (Asn-Ser-Thr) within the gamma-MSH domain. The alpha-MSH sequence is C-terminally flanked by the Gly-Lys-Lys amidation signal while the joining peptide is not amidate.
在两栖动物的中间部，阿黑皮素原（POMC）衍生肽的分泌受多种因素控制，包括经典神经递质和神经肽。为了探究有关泽蛙POMC基因表达调控的问题，我们分离并鉴定了蛙POMC的全长cDNA。从蛙垂体文库中分离出的一个cDNA克隆包含一个780 bp的开放阅读框，预测编码一个260个氨基酸的POMC蛋白。蛙POMC的结构与其他物种的POMC在氨基酸序列上有相当大的相似性。特别是，α-促黑素（α-MSH）的序列在蛙和迄今为止研究的所有哺乳动物物种中是相同的，而促肾上腺皮质激素（ACTH）和β-内啡肽与其人类对应物分别具有79%和84%的同源性。蛙POMC在γ-MSH结构域内仅含有一个潜在的天冬酰胺连接的N-糖基化信号（Asn-Ser-Thr）。α-MSH序列的C末端侧翼是Gly-Lys-Lys酰胺化信号，而连接肽不被酰胺化。
