Transition of Escherichia coli from aerobic to micro-aerobic conditions involves fast and slow reacting regulatory components
Transition of Escherichia coli from aerobic to micro-aerobic conditions involves fast and slow reacting regulatory components
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DOI：
10.1074/jbc.m700728200
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发表时间：
2007-04-13
影响因子：
4.8
通讯作者：
Green, Jeffrey
中科院分区：
文献类型：
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作者：
Partridge, Jonathan D.;Sanguinetti, Guido;Green, Jeffrey
在系统层次上理解生命是生物学的一个主要目标。大肠杆菌为实现这一目标提供了最好的机会之一。它是一种代谢多样的细菌，能够对氧气供应的变化做出反应。这种能力是其生活方式的重要组成部分，使其能够在有氧外部环境和宿主肠道缺氧条件下茁壮成长。恒化器培养的受控生长条件与转录谱分析相结合，以研究从好氧条件向微好氧条件过渡期间的转录组动态。除了可预测的变化，在转录编码蛋白质的中央代谢，转录参与氧化还原反应性金属（铜和铁）的稳态，和细胞包膜应力的丰度显着改变。为了进一步了解调控网络的反应，使用概率建模方法推断了在向微需氧条件过渡期间关键转录因子的活性，该方法揭示了直接氧传感器FNR的反应是快速和过度的，而间接氧传感器ArcA的反应更慢。类似地，单元包络应力传感器RpoE和CpxR分别快速和更慢地反应。因此，它建议，在监管网络中的快速和缓慢反应的组件相结合的系统中，其中的信号被感知的两个或两个以上的功能相关的转录因子控制重叠的调节子的一个功能。
Understanding life at a systems level is a major aim of biology. The bacterium Escherichia coli offers one of the best opportunities to achieve this goal. It is a metabolically versatile bacterium able to respond to changes in oxygen availability. This ability is a crucial component of its lifestyle, allowing it to thrive in aerobic external environments and under the oxygen-starved conditions of a host gut. The controlled growth conditions of chemostat culture were combined with transcript profiling to investigate transcriptome dynamics during the transition from aerobic to micro-aerobic conditions. In addition to predictable changes in transcripts encoding proteins of central metabolism, the abundances of transcripts involved in homeostasis of redox-reactive metals ( Cu and Fe), and cell envelope stress were significantly altered. To gain further insight into the responses of the regulatory networks, the activities of key transcription factors during the transition to micro-aerobic conditions were inferred using a probabilistic modeling approach, which revealed that the response of the direct oxygen sensor FNR was rapid and overshot, whereas the indirect oxygen sensor ArcA reacted more slowly. Similarly, the cell envelope stress sensors RpoE and CpxR reacted rapidly and more slowly, respectively. Thus, it is suggested that combining rapid and slow reacting components in regulatory networks might be a feature of systems in which a signal is perceived by two or more functionally related transcription factors controlling overlapping regulons.