Calcium regulation of flagellar motility

钙对鞭毛运动的调节

• 批准号: 7265245
• 负责人: Elizabeth F Smith
• 金额: $ 26.22万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-08-01 至 2008-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7265245
• 关键词: Address; Affect; Biochemical; Biological Assay; Calcium; Calcium Signaling; Calcium-Binding Proteins; Calmodulin; Calmodulin-Binding Proteins; Cell model; Characteristics; Chlamydomonas; Chlamydomonas reinhardtii; Cilia; Ciliary Motility Disorders; Complex; Cytoskeleton; Databases; Decompression Sickness; Defect; Development; Developmental Process; Dynein ATPase; Dyskinetic syndrome; Embryo; Epithelial Cells; Eukaryota; Eukaryotic Cell; Expressed Sequence Tags; Flagella; Genes; Genetic; Goals; Green Algae; Human Genome; In Vitro; Label; Left; Mediating; Methods; Microtubules; Molecular; Molecular Motors; Nodal; Organism; Patients; Phosphotransferases; Production; Proteins; Radial; Range; Regulation; Research; Shapes; Signal Transduction; Signal Transduction Pathway; Situs Inversus; Slide; Sucrose; Syndrome; System; Testing; Upper arm; Work; cell motility; cell type; density; design; genetic regulatory protein; in vitro Assay; insight; morphogens; mutant; research study; sedimentation coefficient; sensor; size

DESCRIPTION (provided by applicant): The long-range goal of this project is to determine the mechanism by which the molecular motor dynein is regulated to produce the complex waveforms characteristic of beating eukaryotic cilia and flagella. The proposed research is specifically aimed at understanding how changes in calcium modulate the size and shape of ciliary and flagellar bends to control motility. Several studies have indicated that the flagellar central apparatus is a key component of a signal transduction pathway that regulates dynein activity to modulate waveform. The objectives of this proposal are founded on the hypothesis that the central apparatus locally controls a calcium sensor to regulate dynein activity, and that calmodulin and an axonemal calmodulin dependent kinase mediate the calcium signal. The proposed experiments are designed to test this hypothesis and to identify axoneme components involved in the calmodulin-mediated signal transduction pathway. The Specific Aims are: 1) to identify calmodulin-binding proteins associated with the central apparatus; 2) to characterize calmodulin dependent kinases associated with the axoneme; and 3) to determine if the activities of particular dynein subforms attached to specific subsets of doublet microtubules are preferentially modulated by changes in calcium. The unicellular green alga, Chlamydomonas reinhardtii, is the organism of choice for these studies as it is the only system that offers motility mutants, virtually unlimited material for biochemical approaches, and unique in vitro functional assays. Many of the genes encoding flagellar proteins in Chlamydomonas show high sequence similarity with genes in the human genome and EST databases. Therefore, the information obtained in Chlamydomonas will be directly applicable to higher eukaryotes and may provide insight into defects that result in primary cilia dyskinesia including Kartegener's syndrome. Studies of dynein regulation and control of flagellar waveform will also impact upon our understanding of certain developmental processes. For example, the nodal cilia in developing embryos have been implicated in the production of a morphogen gradient responsible for generating left-right asymmetry. This result explains the observation that about 50% of patients with immotile-cilia syndrome also have situs inversus. Interestingly, nodal cilia utilized during development do not assemble a central apparatus and beat with a different waveform than cilia of epithelial cells found in the same organism. This observation further illustrates the importance of controlling ciliary and flagellar waveforms appropriate for particular cell types.

描述（由申请人提供）：本项目的长期目标是确定调节分子马达动力蛋白以产生具有真核纤毛和鞭毛搏动特征的复杂波形的机制。拟议的研究是专门针对了解钙的变化如何调节纤毛和鞭毛弯曲的大小和形状，以控制运动。一些研究表明，鞭毛中央器是调节动力蛋白活性以调制波形的信号转导途径的关键组成部分。这个建议的目的是建立在假设中央装置局部控制钙传感器调节动力蛋白活性，钙调蛋白和轴丝钙调蛋白依赖性激酶介导的钙信号。拟议的实验旨在验证这一假设，并确定轴丝成分参与钙调素介导的信号转导途径。的 具体目标是：1）鉴定与中枢器相关的钙调蛋白结合蛋白; 2）表征与轴丝相关的钙调蛋白依赖性激酶;和3）确定附着于双联体微管的特定亚群的特定动力蛋白亚型的活性是否优先受钙的变化调节。单细胞绿色衣原体，莱茵衣藻，是这些研究的首选生物体，因为它是唯一的系统，提供运动突变体，几乎无限的材料，生化方法，和独特的体外功能测定。 许多编码衣原体鞭毛蛋白的基因与人类基因组和EST数据库中的基因显示出高度的序列相似性。因此，在衣原体获得的信息将直接适用于高等真核生物，并可能提供洞察缺陷，导致原发性纤毛运动障碍，包括Kartegener综合征。动力蛋白调控鞭毛波形的研究也将影响我们对某些发育过程的理解。例如，发育中的胚胎中的结节纤毛与负责产生左右不对称的形态发生梯度的产生有关。这一结果解释了约50%的不动纤毛综合征患者也有内脏逆位的观察结果。有趣的是，在发育过程中使用的结纤毛不组装一个中央装置，并与在同一生物体中发现的上皮细胞的纤毛相比，以不同的波形跳动。这一观察结果进一步说明了控制适合于特定细胞类型的纤毛和鞭毛波形的重要性。