STRUCTURE AND FUNCTION OF CYTOPLASMIC MOTORS

细胞质马达的结构和功能

• 批准号: 6290626
• 负责人: Thomas S Reese
• 金额: --
• 依托单位: NATIONAL INSTITUTE OF NEUROLOGICAL DISORDERS AND STROKE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6290626
• 关键词: Escherichia coli; actins; axon; cilium /flagellum motility; cytoskeleton; dynein ATPase; intracellular transport; kinesin; membrane structure; microtubules; myosins; neurofilament; neuronal transport; neurons; organelles; protein purification; protein structure function; protoplasm motility

This project investigates the functions of cytoplasmic motors in neurons in order to understand fast and slow axonal transport. Negatively charged macromolecular assemblies injected into the squid giant axon move in the anterograde direction at the slow rate. Of particular interest is that neurofilament proteins as well as actin and microtubule fragments move anterogradely along some type of intracellular tract. Recent results suggest that these tracts are microtubule bundles and that the motors come from the soluble pools of conventional kinesin. Indeed, depolymerizing the axonal microtubules blocks slow neurofilament transport. We were recently surprised to find that dimeric tubulin is also transported as well as diffusing. even under depolymerizing conditions. Thus, the slow motor applies to a wide variety of substrates ranging down to diffusible proteins which are given a directional bias. Myosin motors in squid axoplasm now appear to belong to several families of myosins and brain myosin II is likely to predominate on axoplasmic organelles. In the squid giant axon parallel actin filaments intertwine with the microtubule bundles. These have mixed polarities, suggesting that they might carry organelles to and from the microtubule bundles but they may also have a structural role. - axonal transport, organelle transport, kinesin, myosin actin, slow transport, flagellar motors

该项目研究神经元中细胞质马达的功能，以了解快速和慢速轴突运输。注入鱿鱼巨轴突中的带负电的大分子组件以缓慢的速度沿顺行方向移动。特别令人感兴趣的是，神经丝蛋白以及肌动蛋白和微管片段沿着某种类型的细胞内道顺行移动。最近的结果表明，这些束是微管束，并且马达来自传统驱动蛋白的可溶性池。事实上，解聚轴突微管会阻碍缓慢的神经丝运输。我们最近惊讶地发现二聚体微管蛋白也可以运输和扩散。即使在解聚条件下。因此，慢速电机适用于多种底物，范围小至具有方向性偏差的可扩散蛋白质。鱿鱼轴浆中的肌球蛋白马达现在似乎属于几个肌球蛋白家族，并且脑肌球蛋白 II 可能在轴浆细胞器上占主导地位。在鱿鱼巨大的轴突中，平行的肌动蛋白丝与微管束交织在一起。它们具有混合极性，表明它们可能携带细胞器进出微管束，但它们也可能具有结构作用。 - 轴突运输、细胞器运输、驱动蛋白、肌球蛋白肌动蛋白、慢速运输、鞭毛马达