Analyses of sodium bioenergetics in Vibrio cholerae

所有活细胞都在初级离子泵的帮助下建立跨膜电化学梯度。 在许多不同系统发育类群的微生物中发现了初级Na+泵 Na+离子的跨膜循环可能在几种细菌的生理中起着重要作用。 最近完成的许多细菌基因组序列揭示了编码A基因的存在 许多生物体中的各种钠依赖系统，包括一些未知的具有 初级钠能量循环。这表明这些细菌可以利用Na+作为偶联离子 属于H+循环的，或除了H+循环之外的。尽管人们对钠能量循环在体内的作用知之甚少 霍乱弧菌的生理学，霍乱弧菌编码的多种钠依赖系统的存在 这种生物的基因组值得研究它的各种Na+泵。在本申请中，我们将 霍乱弧菌钠离子挤出酶基因突变株的构建和分析 对细菌生理学这一非常复杂和重要的部分有进一步的了解。我们提出了一个 对细菌钠生物能组分的全面和系统分析 通过使用广泛的基因操作和复杂的生物能量测量相结合。 拟议的研究结果不仅将加强我们对一般生物能量途径的了解 但将为我们和其他人未来对该分子的研究奠定坚实的基础 在微生物中维持离子稳态的装置。钠生物能量学可能在这两种情况下都起到了作用 霍乱弧菌生命周期的环境和致病阶段。因此，我们的研究具有潜力 以产生与细菌生理学相关的基本观点，并将对理解 与霍乱弧菌在环境和宿主腔内的生态学有关的基本生物学概念 适用于多种细菌种类。

All living cells establish transmembrane electrochemical gradients with the help of primary ion pumps. Primary Na+ pumps have been discovered in many microorganisms of quite diverse phylogenic groups and a transmembrane circulation of Na+ ions may play a significant role in the physiology of several bacteria. The recent completion of many bacterial genome sequences revealed the presence of genes encoding a variety of sodium-dependent systems in many organisms, including some that were not known to have a primary sodium cycle of energy. This indicates that these bacteria can utilize Na+ as a coupling ion instead of, or in addition to, the H+ cycle. Although little is known about the role of the sodium cycle of energy in the physiology of Vibrio cholerae, the presence of a multitude of sodium-dependent systems encoded in the genome of this organism merits the investigation of its various Na+ pumps. In the present application we will construct and analyze defined mutants in Na+-extruding enzymes in V. cholerae as a model organism to gain further insights into this very complex and important part of bacterial physiology. We propose a comprehensive and systematic analysis of the components that contribute to bacterial sodium bioenergetics by using extensive genetic manipulations in combination with sophisticated bioenergetic measurements. Results of the proposed study will not only enhance our understanding of the general bioenergetic pathways in bacteria, but will form a solid basis for future investigations, by ourselves and others, of the molecular devices maintaining ion homeostasis in microorganisms. Sodium bioenergetics probably plays a role in both the environmental and pathogenic phases of the V. cholerae life cycle. Thus, our research has the potential for generating fundamental perspectives related to bacterial physiology and will be of value to understanding basic biological concepts related to V. cholerae ecology in the environment and in the lumen of hosts that will be applicable to a variety of bacterial species.