Multiple stress signal integration in the regulation of the complex σS-dependent csiD-ygaF-gabDTP operon in Escherichia coli
Multiple stress signal integration in the regulation of the complex σS-dependent csiD-ygaF-gabDTP operon in Escherichia coli
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DOI：
10.1046/j.1365-2958.2003.03867.x
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发表时间：
2004-02-01
影响因子：
3.6
通讯作者：
Hengge, R
中科院分区：
文献类型：
--
作者：
Metzner, M;Germer, J;Hengge, R
大肠杆菌基因组中的CSID-YGAF-GABDTP区域代表了Sigma（S）控制基因的簇。在这里，我们研究了所有这些基因的启动子结构，sigma因子依赖性，潜在的共调节和环境调节模式。我们发现该区域构成一个复杂的操纵子，表达受三个差异调节的启动子控制：（i）CSID（p）影响所有五个基因的表达，是CAMP-CRP/SIGMA（S）依赖性且依赖性和激活的。在碳饥饿和静止期； （ii）GABD（p1），它是依赖性的（S）依赖性的，并且表现出多种应力诱导，例如Sigma（S）本身； （iii）GABD（P2）[先前由Schneider，B.L.，Ruback，S.，Kiupakis，A.K.，Kasbarian，H.，Pybus，C。和Reitzer，L。（2002）J。Bacteriol。 184：6976-6986]，似乎是NAC/Sigma（70）控制的，并对较差的氮来源做出反应。此外，我们确定了一种新型的阻遏物CSIR，该阻遏物在早期固定阶段以时间方式调节CSID（P）活性。最后，我们提出了Sigma（S）控制的GABT/D介导的γ-氨基丁酸（GABA）分解代谢和谷氨酸在一般应激适应中积累的生理作用。在不同条件下，操纵子内GABD（P1）启动子的激活也反映了这种生理作用，这些条件也诱导了Sigma（S），其中包括转移到酸性pH或高渗透压以及饥饿或固定相。
The csiD-ygaF-gabDTP region in the Escherichia coli genome represents a cluster of sigma(S)-controlled genes. Here, we investigated promoter structures, sigma factor dependencies, potential co-regulation and environmental regulatory patterns for all of these genes. We find that this region constitutes a complex operon with expression being controlled by three differentially regulated promoters: (i) csiD(p), which affects the expression of all five genes, is cAMP-CRP/sigma(S)-dependent and activated exclusively upon carbon starvation and stationary phase; (ii) gabD(p1), which is sigma(S)-dependent and exhibits multiple stress induction like sigma(S) itself; and (iii) gabD(p2)[previously suggested by Schneider, B.L., Ruback, S., Kiupakis, A.K., Kasbarian, H., Pybus, C., and Reitzer, L. (2002) J. Bacteriol. 184: 6976-6986], which appears to be Nac/sigma(70)-controlled and to respond to poor nitrogen sources. In addition, we identify a novel repressor, CsiR, which modulates csiD(p) activity in a temporal manner during early stationary phase. Finally, we propose a physiological role for sigma(S)-controlled GabT/D-mediated gamma-aminobutyrate (GABA) catabolism and glutamate accumulation in general stress adaptation. This physiological role is reflected by the activation of the operon-internal gabD(p1) promoter under the different conditions that also induce sigma(S), which include shifts to acidic pH or high osmolarity as well as starvation or stationary phase.