Nutrient Uptake by the Stalk of Caulobacter crescentus

新月柄杆菌茎对养分的吸收

基本信息

批准号：
7638536
负责人：
Pamela Jane Bonner Brown
金额：
$ 5.17万
依托单位：
TRUSTEES OF INDIANA UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2007
资助国家：
美国
起止时间：
2007-06-15 至 2010-06-14
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/7638536
关键词：
ATP phosphohydrolase Active Biological Transport Affinity Alkaline Phosphatase Amino Acids Area Bacteria Biochemical Biological Models Caulobacter Caulobacter crescentus Cell Shape Cell Size Cell Surface Extensions Cells Complement Cues Diffusion Diphosphates Environment Epitopes Fluorescein Fluoresceins Fluorescence Fluorescence Microscopy Fluorescence Recovery After Photobleaching Genetic Genome Goals Gram-Negative Bacteria Hydrolysis Length Life Marines Methods Microfluidics Modeling Morphology Nutrient Phosphoric Acid Esters Photobleaching Physiology Play Probability Prokaryotic Cells Proteins Proteome Proteomics Proton-Motive Force Radiolabeled Research Role Shapes Starvation Stress Supporting Cell Surface System Testing Variant Vibrio cholerae Work cell growth comparative design glucose transport inhibitor/antagonist inorganic phosphate interest mathematical model neuronal cell body pathogen radiotracer research study response uptake

项目摘要

DESCRIPTION (provided by applicant): The long-term goal of this research is to determine why bacteria undergo specific changes in morphology. Bacteria, including pathogens, are found in a vast array of morphologies; however functions have rarely been attributed to specific shapes. In this work, the function of morphological changes in bacteria with cell membrane extensions, known as stalks, will examined as a model system to study the function of morphological adaptation. Recent mathematical models suggest that in nutrient limited environments, such as those inhabited by the stalked bacteria, increasing the length of the cell (and not the surface area) is the most important factor in increasing the efficiency of nutrient uptake. This suggests that the stalk plays a predominant role in the uptake of nutrients and promotes cell growth. Indeed, phosphate limitation is known to induce elongation of the stalk of Caulobacter crescents. In this work the contribution of stalks to nutrient uptake will be studied using two Gram negative bacteria, C. crescentus and Asticcacaulis biprosthecum. The comparative analysis between the mechanisms of nutrient uptake in these two bacterial species will help determine if the stalks arose by common descent or independently as consequence of living in similar nutrient-depleted environments. In this proposal, a multi-disciplinary approach is utilized to determine how nutrients are taken up by the stalk and transported to the cell body to be metabolized. Approaches used in this study will include fluorescence microscopy, microfluidics, proteomics, physiology, and mathematical modeling. The specific aims of this proposal are to: 1). determine the rates of diffusion of nutrients from the stalk to the cell body, 2). determine the mechanism and capacity of nutrient uptake by stalks, and 3). determine the complement of stalk proteins. The results of the experiments outlined in this proposal will provide valuable information about the stalk, a morphological adaptation, which likely allows the stalked bacteria to persist in nutrient-limited environments. Cell shape changes in response to environmental cues are well documented in a number of bacterial systems, including pathogens. Enhancing our understanding of how bacterial cell shapes are maintained, function, and change will provide valuable information about the ability of bacteria to persist in unfavorable environments. This information can be used to design strategies to impede the persistence and proliferation of bacteria in specific environments.

描述（由申请人提供）：这项研究的长期目标是确定细菌为何经历形态学的特定变化。细菌，包括病原体，在各种形态中发现。但是，功能很少归因于特定形状。在这项工作中，细胞膜延伸（称为茎）的形态变化的功能将被视为研究形态适应功能的模型系统。最近的数学模型表明，在养分有限的环境中，例如茎细菌居住的环境，增加细胞的长度（而不是表面积）是提高养分摄取效率的最重要因素。这表明茎在摄取营养并促进细胞生长中起主要作用。实际上，已知磷酸盐的限制会诱导花椰菜新月形的茎伸长。在这项工作中，将使用两种革兰氏阴性细菌，即新月梭菌和asticcacaulis biprosthecum研究茎对营养摄取的贡献。这两种细菌物种中养分吸收机制之间的比较分析将有助于确定茎是通过共同下降或独立而独立的，因为生活在类似的营养不足的环境中。在此提案中，采用了多学科方法来确定茎如何吸收营养并将其转运到细胞体进行代谢。这项研究中使用的方法将包括荧光显微镜，微流体，蛋白质组学，生理和数学建模。该提案的具体目的是：1）。确定从茎到细胞体的养分扩散速率，2）。确定茎的营养吸收的机制和能力，以及3）。确定茎蛋白的补体。该提案中概述的实验结果将提供有关茎的有价值的信息，即形态学适应，这可能使茎细菌可以持续存在于营养限制的环境中。在包括病原体在内的许多细菌系统中，对环境线索的响应响应响应。增强我们对细菌细胞形状如何保持，功能和变化的理解将提供有关细菌在不利环境中持续存在的能力的有价值的信息。这些信息可用于设计策略，以阻止特定环境中细菌的持久性和扩散。