Chromatin- and transcription-related factors repress transcription from within coding regions throughout the Saccharomyces cerevisiae genome.
Chromatin- and transcription-related factors repress transcription from within coding regions throughout the Saccharomyces cerevisiae genome.
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DOI：
10.1371/journal.pbio.0060277
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发表时间：
2008-11-11
期刊：
影响因子：
9.8
通讯作者：
Winston F
中科院分区：
文献类型：
--
作者：
Cheung V;Chua G;Batada NN;Landry CR;Michnick SW;Hughes TR;Winston F
以前对酿酒酵母的研究已经证明，在特定的突变体中，编码区内的隐蔽启动子激活转录。我们对秘密转录进行了全面的分析，以确定通常抑制秘密启动子的因素，确定全基因组的秘密转录的数量，并研究通过秘密转录表达遗传信息的可能性。我们的结果表明，控制染色质结构和转录的大量因子需要抑制酿酒酵母基因组中至少1000个位置的隐蔽转录。两个结果表明，一些隐晦的抄本被翻译了。首先，正如预期的那样，许多神秘的文本包含一个ATG和一个至少由100个密码子组成的开放阅读框架。其次，几个神秘的转录本被翻译成蛋白质。此外，在营养转变后，在野生型细胞中瞬时诱导了测试的隐蔽转录子集，这表明可能在响应生长条件变化时发挥了生理作用。综上所述，我们的结果表明，在正常生长过程中，基因表达的全球完整性由一系列因素维持，并表明在改变的遗传或生理条件下，可能会发生替代遗传信息的表达。最近的研究表明，真核生物基因组中转录成RNA的比例比之前认为的要多得多。在酿酒酵母中，当特定因子缺陷时，几个编码区内的隐蔽启动子变得活跃，并产生与基因3‘部分相对应的较短转录本。(转录从基因的5‘端进行到3’端。)对秘密转录的全面分析确定了通常抑制这一事件的因素。我们发现，至少需要50个因子来抑制隐蔽转录，其中许多涉及染色质结构和转录。其他结果表明，秘密转录的可能性是广泛存在的，始于酿酒酵母基因组中的至少1000个位置。在产生隐秘转录本的突变体中，一些转录本被翻译成蛋白质，这些蛋白质通常不是在未经修饰的野生型细胞中制造的。最后，在野生型细胞中，在营养转变后，一个隐蔽转录子的子集被瞬时诱导，这表明隐藏转录可能起到了作用。综上所述，我们的结果表明，基因表达的正常模式是由广泛的因素维持的，并表明，在遗传或生理条件改变的情况下，可能会发生替代遗传信息的表达。来自开放阅读框架内的转录。酿酒酵母通常被许多染色质和转录相关因子抑制，具有广泛传播和表达替代遗传信息的潜力。
Previous studies in Saccharomyces cerevisiae have demonstrated that cryptic promoters within coding regions activate transcription in particular mutants. We have performed a comprehensive analysis of cryptic transcription in order to identify factors that normally repress cryptic promoters, to determine the amount of cryptic transcription genome-wide, and to study the potential for expression of genetic information by cryptic transcription. Our results show that a large number of factors that control chromatin structure and transcription are required to repress cryptic transcription from at least 1,000 locations across the S. cerevisiae genome. Two results suggest that some cryptic transcripts are translated. First, as expected, many cryptic transcripts contain an ATG and an open reading frame of at least 100 codons. Second, several cryptic transcripts are translated into proteins. Furthermore, a subset of cryptic transcripts tested is transiently induced in wild-type cells following a nutritional shift, suggesting a possible physiological role in response to a change in growth conditions. Taken together, our results demonstrate that, during normal growth, the global integrity of gene expression is maintained by a wide range of factors and suggest that, under altered genetic or physiological conditions, the expression of alternative genetic information may occur. Recent studies have shown that much more of the eukaryotic genome is transcribed into RNA than previously thought. In Saccharomyces cerevisiae, when particular factors are defective, cryptic promoters within several coding regions become active and produce shorter transcripts corresponding to the 3′ portions of genes. (Transcription proceeds from the 5′ end of genes to the 3′ end.) A comprehensive analysis of cryptic transcription identified the factors that normally repress this event. We find that at least 50 factors, many involved in chromatin structure and transcription, are required to repress cryptic transcription. Other results suggest that the potential for cryptic transcription is widespread, initiating from at least 1,000 locations across the S. cerevisiae genome. In mutants in which cryptic transcripts are produced, some of the transcripts are translated into proteins not normally made in unmodified, wild-type cells. Finally, in wild-type cells, a subset of cryptic transcripts is transiently induced following a nutritional shift, suggesting a possible role for cryptic transcription. Taken together, our results demonstrate that the normal pattern of gene expression is maintained by a wide range of factors and suggest that, under altered genetic or physiological conditions, the expression of alternative genetic information may occur. Transcription from within open reading frames inS. cerevisiae, which is normally repressed by many chromatin- and transcription-related factors, has the potential to be widespread and to express alternative genetic information.
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DOI：
10.1126/science.1135862
发表时间：
2007-02-02
期刊：
Science (New York, N.Y.)
影响因子：
--
作者：
Driscoll R;Hudson A;Jackson SP
通讯作者：
Jackson SP
影响因子：
56.9
作者：
Carninci, P;Kasukawa, T;Hayashizaki, Y
通讯作者：
Hayashizaki, Y
影响因子：
64.5
作者：
Basehoar, AD;Zanton, SJ;Pugh, BF
通讯作者：
Pugh, BF
影响因子：
5.3
作者：
Chu, YY;Sutton, A;Prelich, G
通讯作者：
Prelich, G
影响因子：
10.5
作者：
Ashe, HL;Monks, J;Proudfoot, NJ
通讯作者：
Proudfoot, NJ