Molecular and Genetic Analysis of Flagellar Dyneins

描述(申请人提供)：已知真核生物纤毛和鞭毛的运动依赖于沿双微管运动的动力蛋白ATPase马达。鞭毛动力蛋白必须被调节以协调它们在正常弯曲形成和繁殖过程中的活动，此外还必须调节节拍频率和波形以响应变化的生理要求。最近，两个外排动力蛋白组装所必需的基因ODA7和ODA8被鉴定为Lc1的同源基因，它与HC Gamma动力蛋白催化结构域结合，可能是一个调节轻链。将测试Oda7p和Oda8p作为HCα和HCβ调节轻链的假设功能。支架蛋白被认为是连接每一对微管上的多个动力蛋白亚型的纽带。基于干扰动力蛋白组装和功能的插入突变，已经克隆了两个候选支架蛋白基因(PF13和ODA16)。建议通过实验来确定每个基因产物在动力蛋白与微管双重体表面的调节蛋白对接中的作用。Kinesins是在鞭毛中发现的另一个微管相关马达蛋白家族，但它们在鞭毛运动中的作用尚不清楚。鞭毛运动的全局调节涉及到由放射状辐条在双线相关动力蛋白和中心微管相关复合体之间传递的信号。两个中心对投影在这一过程中的作用将通过突变来研究，该突变破坏了一个投影(CPCL)和RNAi介导的在另一个投影(Klp1)中发现的激动素的敲除。对中心对动蛋白的研究将扩展到包括所有被确认为中心对蛋白的动蛋白，并将使用敲除菌株来筛选中心对动蛋白基因的零突变。

DESCRIPTION (provided by applicant): The motility of eukaryotic cilia and flagella is known to depend on dynein ATPase motors that move along doublet microtubules. Flagellar dyneins must be regulated to coordinate their activity during normal bend formation and propagation, and additionally to modulate beat frequency and waveform in response to changing physiological requirements. Two genes essential for outer row dynein assembly, ODA7 and ODA8, have recently been identified as homologs of LC1, which binds to the HC gamma dynein catalytic domain and may act as a regulatory light chain. Hypothesized functions of Oda7p and Oda8p as HC alpha and HC beta regulatory light chains will be tested. Scaffold proteins have been hypothesized to function as links between multiple dynein isoforms along each doublet microtubule. Two candidate scaffold protein genes (PF13 and ODA16) have been cloned based on insertional mutations that disrupt dynein assembly and function. Experiments are proposed to define the role of each gene product in docking dyneins to regulatory proteins on the doublet microtubule surface. Kinesins represent another family of microtubule associated motor proteins found in flagella, but their role in flagellar motility is not known. Global regulation of flagellar motility involves signals transmitted by radial spokes between doublet-associated dyneins and the central pair microtubule-associated complex. The role of two central pair projections in this process will be studied using a mutation that disrupts one projection (cpcl) and RNAi-mediated knockdown of a kinesin found in another projection (Klp1). Work on central pair kinesins will be extended to include all kinesins identified as central pair proteins, and knockdown strains will be used to screen for null mutations in central pair kinesin genes.