Flagellar Length Control in Chlamydomonas: The Role of Intraflagellar Transport and Turnover

衣藻中的鞭毛长度控制：鞭毛内运输和周转的作用

• 批准号: 0416310
• 负责人: Wallace Marshall
• 金额: $ 38.35万
• 依托单位: University of California-San Francisco
• 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 2007-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0416310&HistoricalAwards=false
• 关键词: Flagellar; Length; Control; Chlamydomonas; Role

How cells regulate organelle size is a fundamental question in cell biology. In this project the eukaryotic flagellum will be used as a model system for studies of organelle size regulation, by reducing the problem of measuring size to a single dimension: length. Flagella undergo continuous turnover, and the length control mechanism must balance the rates of assembly and disassembly to maintain a steady-state length. Several models have been proposed to explain this balance. One model relies on the inherent length-dependence of intraflagellar transport (IFT), an active transport process that occurs within flagella. Based on prior studies of IFT, it is predicted that the efficiency of transport will decrease as flagellar length increases, leading to a balance-point between assembly and disassembly occurring at a unique length. An alternative model proposes that length is regulated by a length-sensor coupled to a feedback control system. This project will test these models by examining the mechanistic basis of flagellar length mutants. The balance point model predicts that such mutants must affect either transport or turnover. A combination of genetics and microscopy will be used to test whether length-altering mutants can be entirely explained by changes in the rates of turnover or transport. This project will provide research training for undergraduate and graduate students.

细胞如何调节细胞器大小是细胞生物学的一个基本问题。 在该项目中，真核鞭毛将被用作细胞器尺寸调节研究的模型系统，通过将测量尺寸的问题减少到单一维度：长度。 鞭毛不断更新，长度控制机制必须平衡组装和拆卸的速率以维持稳态长度。 已经提出了几种模型来解释这种平衡。 一个模型依赖于鞭毛内运输（IFT）固有的长度依赖性，这是一种发生在鞭毛内的主动运输过程。 根据IFT的先前研究，预计运输效率将随着鞭毛长度的增加而降低，导致组装和拆卸之间的平衡点出现在独特的长度处。 另一种模型提出，长度由与反馈控制系统耦合的长度传感器调节。 该项目将通过检查鞭毛长度突变体的机制基础来测试这些模型。 平衡点模型预测此类突变体必定会影响运输或周转。 遗传学和显微镜学的结合将被用来测试长度改变突变体是否可以完全通过周转率或运输率的变化来解释。 该项目将为本科生和研究生提供研究培训。