A Novel Myosin Required for Dictyostelium Development

盘基网柄菌发育所需的新型肌球蛋白

• 批准号: 0424704
• 负责人: Margaret Titus
• 金额: $ 36万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-01 至 2008-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0424704&HistoricalAwards=false
• 关键词: Novel; Myosin; Required; Dictyostelium; Development

The ability to sense and respond to nutrient levels in the environment is essential for the survival of organisms. One strategy employed by single cells is exemplified by Dictyostelium, which survives a food shortage by initiating a simple, yet elegant, developmental program resulting in the formation of spores. How do Dictyostelium detect that food has become limiting and then initiate their developmental program? The available data indicate that they sense changes in the levels of an uncharacterized secreted factor(s) that allow them to monitor the ratio of Dictyostelium cells to their food source, bacteria. Failure to secret this factor(s) results in a lack of response to a loss of food, and the cells do not develop spores. A Dictyostelium mutant that fails to initiate the developmental cycle because it does not secrete the critical factor(s) required for monitoring food levels has been identified. This mutant is a useful tool that will be exploited to identify the factor(s) that triggers the onset of development in Dictyostelium. Two aims will be pursued: (1) A biochemical approach will be used to isolate and fully characterize the factor; (2) The molecular basis for the mutant phenotype will be determined. The mutant gene encodes a novel type of myosin. The role of this motor protein in the secretion of a critical developmental factor will be investigated. The successful completion of this project should provide fundamentally important information about how Dictyostelium employs a secreted factor(s) to initiate development and the role of a unique myosin in the process. Identification of this triggering mechanism should then serve as a paradigm for how secreted factors are used to monitor an organism's environment as well as initiate key developmental processes. This project will provide research training for post-doctoral associates, graduate students, and undergraduates.

感知和响应环境中营养水平的能力对于生物体的生存至关重要。单细胞所采用的一种策略以网囊藻为例，它通过启动一个简单而优雅的发育程序，导致孢子的形成，从而在食物短缺时生存下来。网骨藻如何发现食物已经变得有限，然后启动它们的发育程序？现有的数据表明，他们感觉到一种未表征的分泌因子水平的变化，这使他们能够监测网骨藻细胞与其食物来源细菌的比例。不能分泌这种因子会导致对食物损失缺乏反应，细胞不会产生孢子。已经鉴定了一种不能启动发育周期的网囊藻突变体，因为它不分泌监测食物水平所需的关键因子。这种突变体是一种有用的工具，将被利用来确定触发发展的开始在网骨藻的因素（S）。将追求两个目标：（1）将使用生物化学方法分离并充分表征该因子;（2）将确定突变表型的分子基础。突变基因编码一种新型肌球蛋白。将研究这种马达蛋白在关键发育因子分泌中的作用。该项目的成功完成应该提供关于网骨藻如何利用分泌因子启动发育以及独特肌球蛋白在该过程中的作用的基本重要信息。这种触发机制的识别，然后应该作为一个范例，分泌因子是如何用来监测生物体的环境，以及启动关键的发展过程。 该项目将为博士后、研究生和本科生提供研究培训。