摘要
一个单个哺乳动物的抄本通常编码一蛋白质，但是 GNAS (G 蛋白质伪 - 子单元) 的抄本包含二个读物框架并且生产二在结构上无关的蛋白质， XL 伪 s 和 ALEX。没有其它证实象 GNAS 一样双编码的抄本迄今为止被报导了，尽管许多如此的候选人基因被生物信息学分析预言了。在这研究，我们构造了一系列向量测试二个蛋白质产品怎么在 vitro 从一个单个抄本被翻译。ORF (开的读框架) 的长度，第一 8 月的位置和 Kozak 主题被发现是重要因素。这些因素，以及 55-bp NMD (调停胡说八道的 mRNA 腐烂) 规则，为候选人在生物信息学搜索被使用双编码的抄本。分别地， 1307， 750 和 474 个 two-ORF-containing 抄本的一个总数分别地， 170， 89 和 70 哪个被发现是潜在的双编码的抄本在人，老鼠和老鼠被发现。大多数抄本在种类之中显示出低保存。有趣地，双编码的抄本显著地从锌手指蛋白质家庭为抄本被充实，它通常是涉及抄写过程的规定的 DNA 有约束力的蛋白质。
A single mammalian transcript normally encodes one protein, but the transcript of GNAS （G-protein u-subunit） contains two reading frames and produces two structurally unrelated proteins, XLas and ALEX. No other confirmed GNAS-Iike dual-coding transcripts have been reported to date, even though many such candidate genes have been predicted by bioinformatics analysis. In this study, we constructed a series of vectors to test how two protein products were translated from a single transcript in vitro. The length of the ORF （open reading frame）, position of the first AUG and the Kozak motif were found to be important factors. These factors, as well as 55-bp NMD （nonsense-mediated mRNA decay） rule, were used in a bioinformatics search for candidate dual-coding transcripts. A total of 1307, 750 and 474 two-ORF-containing transcripts were found in human, mouse and rat, respectively, of which 170, 89 and 70, respectively, were found to be potential dual-coding transcripts. Most transcripts showed low conservation among species. Interestingly, dual-coding transcripts were significantly enriched for transcripts from the zinc-finger protein family, which are usually DNA-binding proteins involved in regulation of the transcription process.
