Bet-hedging and communication in E. coli? - Investigations of heterogeneous gene expression of carbohydrate uptake systems

大肠杆菌中的对冲和交流？

• 批准号: 218594975
• 负责人: Dr. Katja Bettenbrock
• 金额: --
• 依托单位: Max-Planck-Institut für Dynamik komplexer technischer Systeme
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2012
• 资助国家: 德国
• 起止时间: 2011-12-31 至 2016-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/218594975?language=en
• 关键词: Bet; hedging; communication; E.; coli

Bistable expression of the lac operon has been known for quite a long time. Although the molecular mechanisms of this expression pattern provoked by gratuitous inducers have been clarified, no investigations are available that deal with induction by the original substrate lactose or that try to elucidate the potential benefit of this expression. The project at hand will analyze heterogeneity of lac operon expression after induction with low levels of lactose, the natural substrate that is actively metabolized by the cells. A potential growth benefit of induced cells will be investigated. Another important aspect of the project will be the analysis of cAMP in heterogeneous lac operon expression. It is well established that cAMP represents a hunger signal in E. coli and influences the expression of most carbohydrate uptake systems. Nevertheless the reasons underlying cAMP control have never been investigated in detail. As most cAMP is expelled into the medium this molecule has the potential to serve as a hunger signal not only at the cellular but also at the population level. The investigations carried out in the frame of this project will deal with this topic. Lastly, we will analyze induction properties of carbohydrate uptake systems if cells are subjected to low concentrations of two different carbohydrates. Different induction patterns are possible, cells that induce uptake of both substrates, of one substrate or of none. The results promise to give interesting insights into possible bet-hedging strategies and sociobiology of E. coli.

乳糖操纵子的双稳态表达已经知道了相当长的时间。虽然这种表达模式引起的无偿诱导剂的分子机制已被澄清，没有调查是可用的，处理与诱导的原始底物乳糖或试图阐明这种表达的潜在好处。手头的项目将分析低水平乳糖诱导后乳糖操纵子表达的异质性，乳糖是细胞积极代谢的天然底物。将研究诱导细胞的潜在生长益处。该项目的另一个重要方面将是分析cAMP在异质性乳糖操纵子表达中的作用。cAMP在E.并影响大多数碳水化合物摄取系统的表达。然而，cAMP控制的根本原因从未被详细研究过。由于大多数cAMP被排出到培养基中，因此该分子不仅在细胞水平上，而且在群体水平上都有可能充当饥饿信号。在本项目框架内进行的调查将涉及这一主题。最后，我们将分析如果细胞受到低浓度的两种不同的碳水化合物的碳水化合物摄取系统的诱导特性。不同的诱导模式是可能的，细胞诱导两种底物的摄取，一种底物的摄取或不摄取。这些结果有望为E.杆菌