Determination of the Global Pattern of Gene Expression in Yeast Cells by Intracellular Levels of Guanine Nucleotides
Determination of the Global Pattern of Gene Expression in Yeast Cells by Intracellular Levels of Guanine Nucleotides
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DOI：
10.1128/mbio.02500-18
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发表时间：
2019-01-01
期刊：
影响因子：
6.4
通讯作者：
Oliver, Stephen G.
中科院分区：
文献类型：
--
作者：
Hesketh, Andy;Vergnano, Marta;Oliver, Stephen G.
在酿酒酵母中，基因转录与高能嘌呤核苷酸丰度之间的相关性经常被注意到。然而，在缺乏诸如营养状况和生长速度等混杂因素的情况下，没有对这一现象进行系统的调查，并且几乎没有确凿的证据证明两者之间存在因果关系。转录是否从根本上响应细胞内嘌呤核苷酸的感应，而不依赖于特定的营养，仍然是一个重要的问题。抑化培养控制的营养环境表明，ATP和GTP丰度与生长所需基因的转录密切相关。在酿酒酵母中设计了诱导和无效消耗ATP或GTP的短途径，允许分析对这些核苷酸需求增加的转录效应。在使用可发酵碳源葡萄糖的稳态生长过程中，ATP的无用消耗导致细胞内ATP浓度下降，但GTP和鸟苷酸能量电荷（GEC）增加。编码核糖体生物发生蛋白的转录本的表达，以及受SWI/ snf依赖性染色质重塑的启动子控制的转录本的表达，与这些核苷酸库的变化相关。使用不可发酵碳源观察到类似的核苷酸丰度变化，但对生长相关转录程序没有影响。诱导gtp循环途径对核苷酸丰度和基因转录仅具有边际效应。在ATP循环诱导的趋化剂中，呼吸细胞对葡萄糖的转录反应被抑制，而不是GTP循环，这主要与腺嘌呤核苷酸水平的改变有关。本文研究了基因转录是否独立于任何特定营养物质的供应，通过监测ATP和GTP水平来响应细胞的能量状态。在酿酒酵母中设计了诱导和无效消耗ATP或GTP的短途径，并分析了对这些嘌呤核苷酸需求增加对基因转录的影响。尽管葡萄糖抑制过程中基因表达的重编程对腺嘌呤核苷酸水平很敏感，但转录的变化最一致地与GTP和GEC水平的变化相关。结果表明，GTP水平在决定基因如何响应能量供应变化方面起着核心作用，并且任何对真核基因表达控制的全面理解都需要阐明鸟嘌呤核苷酸丰度的变化如何被感知和转导以改变全局转录模式。
Correlations between gene transcription and the abundance of high-energy purine nucleotides in Saccharomyces cerevisiae have often been noted. However, there has been no systematic investigation of this phenomenon in the absence of confounding factors such as nutrient status and growth rate, and there is little hard evidence for a causal relationship. Whether transcription is fundamentally responsive to prevailing cellular energetic conditions via sensing of intracellular purine nucleotides, independently of specific nutrition, remains an important question. The controlled nutritional environment of chemostat culture revealed a strong correlation between ATP and GTP abundance and the transcription of genes required for growth. Short pathways for the inducible and futile consumption of ATP or GTP were engineered into S. cerevisiae, permitting analysis of the transcriptional effect of an increased demand for these nucleotides. During steady-state growth using the fermentable carbon source glucose, the futile consumption of ATP led to a decrease in intracellular ATP concentration but an increase in GTP and the guanylate energy charge (GEC). Expression of transcripts encoding proteins involved in ribosome biogenesis, and those controlled by promoters subject to SWI/SNF-dependent chromatin remodelling, was correlated with these nucleotide pool changes. Similar nucleotide abundance changes were observed using a nonfermentable carbon source, but an effect on the growth-associated transcriptional programme was absent. Induction of the GTP-cycling pathway had only marginal effects on nucleotide abundance and gene transcription. The transcriptional response of respiring cells to glucose was dampened in chemostats induced for ATP cycling, but not GTP cycling, and this was primarily associated with altered adenine nucleotide levels.IMPORTANCE This paper investigates whether, independently of the supply of any specific nutrient, gene transcription responds to the energy status of the cell by monitoring ATP and GTP levels. Short pathways for the inducible and futile consumption of ATP or GTP were engineered into the yeast Saccharomyces cerevisiae, and the effect of an increased demand for these purine nucleotides on gene transcription was analyzed. The resulting changes in transcription were most consistently associated with changes in GTP and GEC levels, although the reprogramming in gene expression during glucose repression is sensitive to adenine nucleotide levels. The results show that GTP levels play a central role in determining how genes act to respond to changes in energy supply and that any comprehensive understanding of the control of eukaryotic gene expression requires the elucidation of how changes in guanine nucleotide abundance are sensed and transduced to alter the global pattern of transcription.