MOLECULAR INTERACTIONS IN MOVING AXONEMES

纤毛和鞭毛存在于各种真核细胞中。 她们的功能障碍与呼吸系统疾病或男性有关 不孕不育。 这项建议有以下两个长期目标：分析 这些轴丝成分的分子和结构特征是 对于轴丝运动的产生是必不可少的，第二，确定 导致特异体形成的分子调控机制 纤毛和鞭毛的弯曲图案。这两个目标都将得到实现 通过对内部动力蛋白手臂的分析，因为在体内这些 结构是产生纤毛和纤毛的必要条件和充分条件 鞭毛型在没有动力蛋白外臂的情况下的运动。 使用的生物体是单细胞绿藻莱茵衣藻。 这种有机体允许通过以下组合分析轴丝 研究方法包括遗传学、电子显微镜和生物化学 程序。衣藻野生型与突变型轴丝的比较 缺少动力蛋白外臂或部分内臂的轴丝形成 这是本提案中概述的许多实验程序的基础。这个 由活动鞭毛制备的内动力蛋白臂与普通鞭毛的比较 突变体中不活动鞭毛来源及内臂缺陷分析 轴丝，将被用来解释翻译后的功能 内臂重链的修饰。 在此基础上，将以下列方式实现长期目标 具体目标： 1.完成结构和分子组成的表征 轴丝衣藻中存在的所有形式的内动力蛋白臂； 2.制定对结构和修改的详细分析 并确定内臂重链的修饰是否为重链 链是控制轴丝运动的机制的一部分； 3.描述与其功能相关的轴丝成分。 辐射辐条缺陷突变体鞭毛活性的恢复； 4.确定轴丝肌动蛋白和钙化肌动蛋白是否直接参与 衣藻体内动力蛋白臂活动的变化 轴丝从纤毛运动到鞭毛型运动。

Cilia and flagella are present in a wide variety of eukaryotic cells. Their disfunction is correlated with respiratory ailments or male sterility. This proposal has the following two long-term objectives: analyze the molecular and structural features of those axonemal components that are essential for the generation of axonemal movement and second, identify the molecular mechanisms of regulation that lead to the formation of specific bending patterns of cilia and flagella. Both objectives will be approached with the analysis of the inner dynein arms, because in vivo these structures are necessary and sufficient to generate both ciliary and flagellar types of movement in the absence of outer dynein arms. The organism used is the unicellular green alga Chlamydomonas reinhardtii. This organism allows for the analysis of the axoneme by a combination of approaches including genetics, electron microscopy and biochemical procedures. The comparison of Chlamydomonas wild-type axonemes with mutant axonemes lacking the outer dynein arms or part of the inner arms forms the basis of many experimental procedures outlined in this proposal. The comparison of inner dynein arms prepared from motile flagella with those from nonmotile flagella and analysis of defective inner arms in mutant axonemes, will be adopted to explain the function of the posttranslational modification of inner arm heavy chains. On this basis the long-term objective will be approached with the following specific aims: 1. complete the characterization of the structure and molecular composition of all forms of inner dynein arms present in Chlamydomonas axonemes; 2. develop a detailed analysis of the structures and the modifications of inner arm heavy chains and determine whether the modification of heavy chains is part of mechanism controlling axonemal motility; 3. characterize the axonemal components whose function is correlated with the restoration of flagellar activity of radial spoke-defective mutants; 4. determine whether axonemal actin and caltractin directly are involved in those changes of inner dynein arm activity that occur when Chlamydomonas axonemes pass from the ciliary to the flagellar type of motion.