Correlation between growth rates, EIIACrr phosphorylation, and intracellular cyclic AMP levels in Escherichia coli K-12
Correlation between growth rates, EIIACrr phosphorylation, and intracellular cyclic AMP levels in Escherichia coli K-12
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DOI：
10.1128/jb.00819-07
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发表时间：
2007-10-01
影响因子：
3.2
通讯作者：
Gilles, Ernst-Dieter
中科院分区：
文献类型：
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作者：
Bettenbrock, Katja;Sauter, Thomas;Gilles, Ernst-Dieter
在大肠杆菌K-12中，磷酸烯醇化酸依赖性磷酸转移酶系统（PTS）的组分代表了一个信号转导系统，该系统通过磷酸烯醇化酸依赖性蛋白激酶IIA（Crr）（= EIIA（Crr））介导的诱导物排斥和全局调节剂环腺苷酸（cAMP）-cAMP受体蛋白（CRP）介导的分解代谢物阻遏参与碳催化剂的全局控制。我们以系统的方式测量了细胞生长速率与分解代谢物阻遏的关键参数之间的关系，即，采用体外和体内试验测定磷酸化EIIA（Crr）（EIIA（Crr）类似于P）水平和cAMP水平。通过使用各种碳源或通过在连续生物反应器实验中用有限浓度的葡萄糖、蔗糖和甘露醇生长细胞来获得不同的生长速率。与P相似的EIIA（Crr）与EIIA（Crr）的比值和从cAMP-CRP依赖性启动子的活性推导出的细胞内cAMP浓度与0.3 h（-1）和0.7 h（-1）之间的比生长速率相关性良好，分别对应于约138和60 min的世代时间。低于和高于这个范围，这些参数越来越多地从增长率，这可能表明其他全球控制系统，特别是严格放松的响应系统执行的作用越来越大。
In Escherichia coli K-12, components of the phosphoenolpyruvate-dependent phosphotransferase systems (PTSs) represent a signal transduction system involved in the global control of carbon catabolism through inducer exclusion mediated by phosphoenolpyruvate-dependent protein kinase enzyme IIA(Crr) (EIIA(Crr)) (= EIIA(Glc)) and catabolite repression mediated by the global regulator cyclic AMP (cAMP)-cAMP receptor protein (CRP). We measured in a systematic way the relation between cellular growth rates and the key parameters of catabolite repression, i.e., the phosphorylated EIIA(Crr) (EIIA(Crr)similar to P) level and the cAMP level, using in vitro and in vivo assays. Different growth rates were obtained by using either various carbon sources or by growing the cells with limited concentrations of glucose, sucrose, and mannitol in continuous bioreactor experiments. The ratio of EIIA(Crr) to EIIA(Crr)similar to P and the intracellular cAMP concentrations, deduced from the activity of a cAMP-CRP-dependent promoter, correlated well with specific growth rates between 0.3 h(-1) and 0.7 h(-1), corresponding to generation times of about 138 and 60 min, respectively. Below and above this range, these parameters were increasingly uncoupled from the growth rate, which perhaps indicates an increasing role executed by other global control systems, in particular the stringent-relaxed response system.