Taylor B L, Zhulin I B
Department of Microbiology and Molecular Genetics, School of Medicine, Loma Linda University, CA 92350, USA.
Mol Microbiol. 1998 May;28(4):683-90. doi: 10.1046/j.1365-2958.1998.00835.x.
Bacteria use different strategies to navigate to niches where environmental factors are favourable for growth. Chemotaxis is a behavioural response mediated by specific receptors that sense the concentration of chemicals in the environment. Recently, a new type of sensor has been described in Escherichia coli that responds to changes in cellular energy (redox) levels. This sensor, Aer, guides the bacteria to environments that support maximal energy levels in the cells. A variety of stimuli, such as oxygen, alternative electron acceptors, light, redox carriers that interact with the electron transport system and metabolized carbon sources, effect changes in the cellular energy (redox) levels. These changes are detected by Aer and by the serine chemotaxis receptor Tsr and are transduced into signals that elicit appropriate behavioural responses. Diverse environmental signals from Aer and chemotaxis receptors converge and integrate at the level of the CheA histidine kinase. Energy sensing is widespread in bacteria, and it is now evident that a variety of signal transduction strategies are used for the metabolism-dependent behaviours. The occurrence of putative energy-sensing domains in proteins from cells ranging from Archaea to humans indicates the importance of this function for all living systems.
细菌采用不同策略导航至环境因素有利于生长的生态位。趋化作用是一种由特定受体介导的行为反应，这些受体感知环境中化学物质的浓度。最近，在大肠杆菌中描述了一种新型传感器，它对细胞能量（氧化还原）水平的变化作出反应。这种传感器Aer引导细菌前往支持细胞内最大能量水平的环境。多种刺激因素，如氧气、替代电子受体、光、与电子传递系统相互作用的氧化还原载体以及代谢碳源，都会影响细胞能量（氧化还原）水平的变化。这些变化由Aer和丝氨酸趋化受体Tsr检测到，并被转化为引发适当行为反应的信号。来自Aer和趋化受体的多种环境信号在CheA组氨酸激酶水平汇聚并整合。能量感应在细菌中广泛存在，现在很明显，多种信号转导策略被用于依赖代谢的行为。从古细菌到人类的细胞蛋白质中存在假定的能量感应结构域，这表明该功能对所有生命系统都很重要。
