Small RNAs and Vibrio cholerae adaptation to different carbon sources

小RNA和霍乱弧菌对不同碳源的适应

• 批准号: 8477488
• 负责人: Jane May Liu
• 金额: $ 14.75万
• 依托单位: POMONA COLLEGE
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-06-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8477488
• 关键词: Small; RNAs; Vibrio; cholerae; adaptation

DESCRIPTION (provided by applicant): Cholera is a devastating diarrheal disease caused by Vibrio cholerae, a water-born pathogen. V. cholerae must adapt to changing nutrient availability, such as carbon sources, when transitioning between its aquatic reservoirs and the human host. Transcriptional analysis and mutagenesis screens have previously indicated that energy metabolism pathways, particularly the phosphoenolpyruvate (PEP)-carbohydrate phosphotransferase system (PTS), play a major role in the transition of V. cholerae between different niches. However, the components of the V. cholerae PTS remain largely uncharacterized. The long-term goal of this proposal is to elucidate how V. cholerae regulates the PTS to adapt to changing environments. Many small RNAs (sRNAs) are involved in diverse regulatory pathways involving stress-adaptation in V. cholerae and related bacteria. The objective of this proposal is to determine if an sRNA-mediated mechanism is involved in V. cholerae adaptation to different carbon sources. Previous studies have identified sRNAs in the V. cholerae transcriptome that may be involved in regulating the PTS of this facultative pathogen. Strong preliminary data suggests that an sRNA, MtlS, is expressed in a regulated manner and inhibits the expression of mtlA, the mannitol- specific transporter of V. cholerae. The central hypothesis is that V. cholerae uses MtlS-mediated control of gene expression to rapidly adapt to changes in carbon source, contributing to its environmental persistence. The central hypothesis will be tested by pursuing three specific aims. First, the mechanism of sRNA-mediated regulation of mannitol metabolism will be determined. Using biochemical approaches and mutagenesis, effects of MtlS on mtlA expression will be elucidated. The second aim of this proposal will use dual genetic selections to identify minimal mtlA regulatory motifs targeted by MtlS. The third aim of this proposal is to identify the regulator of mtlS expression using biochemical assays and mutagenesis. The experiments proposed here will advance the understanding of the role of sRNAs in carbon metabolism and elucidate components of a central metabolic pathway that may provide targets for vaccines and therapeutics against V. cholerae. Thus, the proposed research is relevant to the NIH's mission of developing fundamental knowledge that will reduce the burdens of human diseases. Furthermore, V. cholerae is an excellent model for other facultative bacteria; thus, this proposal will also provide insight into other known and emerging pathogens. PUBLIC HEALTH RELEVANCE: This project involves determining how the bacterial pathogen Vibrio cholerae, the causative agent of cholera, adapts to different environments. With an estimated greater than one million cases each year, cholera represents a major global public health concern. Understanding the biochemical and physiological changes V. cholerae undergoes while transitioning between aquatic environment and host will provide insights into how we may combat these pathogens with next-generation therapeutics and vaccines.

描述（由申请人提供）：霍乱是一种由霍乱弧菌（一种水生病原体）引起的毁灭性腹泻病。当霍乱弧菌在水生宿主和人类宿主之间转移时，必须适应不断变化的营养物质供应，例如碳源。转录分析和诱变筛选先前表明，能量代谢途径，特别是磷酸烯醇丙酮酸（PEP）-碳水化合物磷酸转移酶系统（PTS），在霍乱弧菌在不同生态位之间的转变中发挥着重要作用。然而，霍乱弧菌 PTS 的成分在很大程度上仍然未知。该提案的长期目标是阐明霍乱弧菌如何调节 PTS 以适应不断变化的环境。 许多小 RNA (sRNA) 参与多种调控途径，涉及霍乱弧菌和相关细菌的应激适应。本提案的目的是确定 sRNA 介导的机制是否参与霍乱弧菌对不同碳源的适应。先前的研究已经鉴定出霍乱弧菌转录组中的 sRNA 可能参与调节这种兼性病原体的 PTS。强有力的初步数据表明，sRNA MtlS 以受调节的方式表达，并抑制霍乱弧菌甘露醇特异性转运蛋白 mtlA 的表达。核心假设是霍乱弧菌利用 MtlS 介导的基因表达控制来快速适应碳源的变化，从而有助于其在环境中的持久存在。 将通过追求三个具体目标来检验中心假设。首先，将确定 sRNA 介导的甘露醇代谢调节机制。使用生化方法和诱变，将阐明 MtlS 对 mtlA 表达的影响。该提案的第二个目标将使用双重遗传选择来识别 MtlS 靶向的最小 mtlA 调控基序。该提案的第三个目标是使用生化测定和诱变来鉴定 mtlS 表达的调节因子。这里提出的实验将增进对 sRNA 在碳代谢中作用的理解，并阐明中央代谢途径的组成部分，该途径可能为霍乱弧菌疫苗和治疗提供靶点。因此，拟议的研究与美国国立卫生研究院发展基础知识以减轻人类疾病负担的使命相关。此外，霍乱弧菌是其他兼性细菌的绝佳模型。因此，该提案还将提供对其他已知和新出现的病原体的深入了解。 公共卫生相关性：该项目涉及确定细菌病原体霍乱弧菌（霍乱的病原体）如何适应不同的环境。据估计，霍乱每年超过一百万例，是全球主要的公共卫生问题。了解霍乱弧菌在水生环境和宿主之间转变时所经历的生化和生理变化将为我们如何利用下一代疗法和疫苗对抗这些病原体提供见解。