MOLECULAR INTERACTIONS IN MOVING AXONEMES

移动轴丝中的分子相互作用

• 批准号: 2392126
• 负责人: GIANNI PIPERNO
• 金额: $ 26.85万
• 依托单位: ICAHN SCHOOL OF MEDICINE AT MOUNT SINAI
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-04-01 至 2000-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2392126
• 关键词: Chlamydomonas; actins; alternatives to animals in research; autoradiography; binding proteins; cilium /flagellum motility; cinematography; confocal scanning microscopy; dynein ATPase; electron microscopy; fluorescence microscopy; gel electrophoresis; image processing; immunoelectron microscopy; immunoprecipitation; intermolecular interaction; microtubules; molecular cloning; phenotype; phosphorylation; polymerase chain reaction; protein structure function; tissue /cell culture

The long-term objective of this proposal is the understanding of the molecular mechanism that creates bending and waveforms of cilia and flagella. To reach this objective studies will be performed to describe the position and function of the inner dynein arms along and across the axonemes of Chlamydomonas flagella. The inner dynein arms produce shear forces at different points along outer doublet microtubules and, therefore, create and maintain axonemal bends. Other axonemal substructures, such as the "dynein regulatory complex" (drc) and the radial spokes modify the waveforms of the axonemes. In contrast, motors, such as the outer dynein arms, affect the beat frequency of the axonemes. The long term objective will be approached through the following specific aims: 1) identify the position within the axoneme of specific light, intermediate and heavy chains of inner dynein arms. 2) identify the function of specific inner dynein arms in the initiation and propagation of axonemal waveforms. 3) describe the interactions occurring in the ensemble of inner dynein arms, radial spokes and drc at the molecular level. 4) determine whether axoneme assembly depends on active transport of specific inner dynein arm subunits. A model of the inner dynein arm organization along and across the axoneme will be tested by these experimental approaches. The following hypotheses also will be tested: 1) each form of inner dynein arm affects a particular characteristic of axonemal waveforms, 2) the protein centrin provides a calcium-dependent regulation of inner dynein arm activity, 3) proximal inner dynein arm subunits are transported actively to their final destination. The axonemes of Chlamydomonas flagella are an excellent model system for studies of cilia and flagella of complex organisms. They are functionally and morphologically similar to axonemes from a variety of sources. Furthermore, they can be analyzed by genetics. Cilia or flagella are appended to various cell types in the human body such as: epithelial cells lining the respiratory tracts, the oviduct cells, sperm cells and the ependymal cells in the spinal cord. Axonemal dysfunctions in humans may cause respiratory ailments or sterility or the "Kartagener's syndrome" or hydrocephalus.

这项建议的长期目标是使人们了解， 产生纤毛弯曲和波形的分子机制， 鞭毛为了达到这一目标，将进行研究，以描述 内动力蛋白臂沿着和横跨 衣原体鞭毛的轴丝。内部动力蛋白臂产生剪切力 力在沿着外部双联体微管的不同点， 从而产生并维持轴丝弯曲。 其他轴丝 亚结构，如“动力蛋白调节复合物”（DRC）和 径向辐条改变轴丝的波形。相比之下，电机， 如外动力蛋白臂，影响轴丝的节拍频率。 将通过以下具体措施实现长期目标 目的： 1)确定特定光在轴丝内的位置， 内部动力蛋白臂的中间链和重链。 2)确定特定的内部动力蛋白臂在启动中的功能 和轴丝波形的传播。 3)描述发生在内部动力蛋白系综中的相互作用 分子水平上的臂、辐射状辐条和DRC。 4)确定轴丝组装是否依赖于 特异性内部动力蛋白臂亚基。 内动力蛋白臂沿着和穿过轴丝的组织模型 将通过这些实验方法进行测试。下列假设 也将被测试：1）每种形式的内部动力蛋白臂影响一个特定的 轴丝波形的特征，2）蛋白质中心蛋白提供了一个 内动力蛋白臂活动的钙依赖性调节，3）近端 内部动力蛋白臂亚基被主动运输到它们的末端， 目的地 衣原体鞭毛的轴丝是一个很好的模型系统， 研究复杂生物体的纤毛和鞭毛。它们在功能上 形态学上与多种来源的轴丝相似。 此外，它们可以通过遗传学进行分析。 纤毛或鞭毛附着在人体的各种细胞类型上 例如：呼吸道、输卵管、 细胞、精子细胞和室管膜细胞。轴丝 人类的功能障碍可能会导致呼吸系统疾病或不育， “卡塔格纳综合征”或脑积水。