Evolution of gnathostome prodynorphin and proenkephalin: Characterization of a shark proenkephalin and prodynorphin cDNAs

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• 作者：Leanne K. Komorowski ; Stephanie G. Lecaude ; Christian G. Westring ; Phillip B. Danielson ; Robert M. Dores ; ^{rdores@du.edu}
• 关键词：Prodynorphin ; Proenkephalin ; Shark ; Evolution
• 刊名：General and Comparative Endocrinology
• 出版年：2012
• 出版时间：1 July, 2012
• 年：2012
• 卷：177
• 期：3
• 页码：353-364
• 全文大小：2144 K

文摘

Analyses of prodynorphin and proenkephalin cDNAs cloned from the central nervous system of the shark, Heterodontus portusjacksoni, provided additional evidence that these two opioid precursor-coding genes were most likely directly derived from a common ancestral gene. The two cDNAs could be aligned by inserting only seven gaps. The prodynorphin cDNA encodes five opioid sequences which could be aligned to opioid positions B through F in the proenkephalin cDNA. The sequence identity within the opioid positions was 59 % at the amino acid level. Shark ¦Á-neo-endorphin, dynorphin A, and dynorphin B have amino acid motifs in common with shark met-enkephalin-8, and shark proenkephalin opioid positions E and F, respectively, which have not been observed in other gnathostome prodynorphin and proenkephalin precursor sequences. Shark prodynorphin encodes both kappa (¦Á-neo-endorphin, dynorphin A, and dynorphin B) and delta (met-enkephalin and leu-enkephalin) opioid sequences. Mixed function prodynorphin precursors (encoding both enkephalins and dynorphins) are also found in representatives of the teleost fishes, lungfishes, and amphibians. It appears that only mammals evolved a prodynorphin precursor that exclusively encodes kappa opioid agonists (dynorphins).