Milton/Trak 1/2 Protein and the Transport of Mitochondria

Milton/Trak 1/2 蛋白和线粒体的运输

• 批准号: 10080033
• 负责人: Thomas L. Schwarz
• 金额: $ 37.17万
• 依托单位: BOSTON CHILDREN'S HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-09-20 至 2022-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10080033
• 关键词: Actins; Adaptor Signaling Protein; Axon; Binding; Biochemical; Biological Assay; Buffers; Cells; Complex; Couples; Cytoplasm; Cytoskeleton; Data; Dendrites; Dissociation; Dynein ATPase; Energy Supply; Equilibrium; GTP Binding; GTPase-Activating Proteins; Guanosine Triphosphate; Guanosine Triphosphate Phosphohydrolases; Heterodimerization; Immobilization; In Vitro; Kinesin; Location; Mediating; Metabolic; Microtubules; Mitochondria; Mitochondrial Proteins; Modeling; Motor; Movement; Mutate; Nature; Neurons; Organelles; Outer Mitochondrial Membrane; PINK1 gene; Parkinson Disease; Pathway interactions; Phenotype; Phosphorylation; Phosphotransferases; Physiological; Proteins; Regulation; Shapes; Signal Pathway; Signal Transduction; Structure; Surface; Synapses; Testing; Ubiquitination; Ursidae Family; Work; aurora B kinase; cell motility; density; in vivo; knock-down; myosin VI; novel strategies; parkin gene/protein; peroxisome; prevent; protein transport; recruit; synaptic inhibition; syntaphilin

Work from this lab and others has established that mitochondrial motility is governed by a motor/adaptor complex that couples both kinesin and dynein motors to the mitochondrial surface. Much, however, remains unknown about how regulation of that complex determines when and where a mitochondrion will stop, or why some mitochondria are long-term stationary, while others only pause briefly before continuing to move. Anchoring proteins are known that can hold mitochondria in place, but the interplay of anchoring proteins and mitochondrial motors is poorly understood. This proposal seeks to understand mechanisms that regulate the assembly of the motor/adaptor complex and signaling pathways that can turn off those motors. The proposal also seeks to understand when mitochondria are merely passively stationary and when they are being actively held in place by an anchor. The exceptional shapes of neurons makes mitochondrial motility and its regulation particularly important so that the branches of axons and dendrites can be properly supplied with mitochondria and certain locations with high energetic demand, such as synapses, can have increased density of mitochondria. This proposal therefore places special emphasis on how mitochondrial dynamics are regulated in axons and on signals that may localize mitochondria to synapses. To better understand mitochondrial regulation, the proposal introduces two novel approaches. One approach is the misdirection of the mitochondrial motor/adaptor complex to peroxisomes so that assembly and regulation of the complex can be studied and mutated away from the endogenous mitochondrial proteins. The other new approach is to use a heterodimerizing agent to attach a constitutively active kinesin motor to mitochondria and thereby test whether mitochondria are being actively held in place by an anchor. In addition, this proposal introduces two new factors that govern the motility of mitochondria, a protein that anchors mitochondria to the actin cytoskeleton, and a kinase that regulates the localization of mitochondria at synapses. In Aim 1 we propose to study how a GTPase domain of Miro regulates the ability of the complex to assemble and what physiological significance there is to the GTPase activity. In Aim 2 we investigate competing models for how elevated Ca2+and the PINK1/Parkin pathway cause mitochondria to stop and ask whether or not they immobilize mitochondria with anchoring proteins. In Aim 3 we investigate the mechanism by which Aurora kinase B inhibits mitochondrial movement and thereby promotes the localization of mitochondria to synapses.

该实验室和其他实验室的工作已经确定线粒体运动是由马达/适配器控制的 将驱动蛋白和动力蛋白马达耦合到线粒体表面的复合物。然而，很多仍然存在 不知道该复合体的调节如何决定线粒体何时何地停止，或者为什么 一些线粒体长期静止，而另一些则仅短暂停顿，然后继续移动。 众所周知，锚定蛋白可以将线粒体固定在适当的位置，但锚定蛋白和线粒体之间的相互作用 人们对线粒体马达知之甚少。该提案旨在了解监管机制 电机/适配器复合体的组装以及可以关闭这些电机的信号通路。提案 还试图了解线粒体何时只是被动静止以及何时主动 由锚固定到位。神经元的特殊形状使得线粒体运动及其调节 特别重要的是，这样轴突和树突的分支才能得到线粒体的适当供应 某些能量需求较高的位置，例如突触，可以增加能量密度 线粒体。因此，该提案特别强调线粒体动力学的调节方式 在轴突和可能将线粒体定位到突触的信号上。为了更好地了解线粒体 监管方面，该提案引入了两种新颖的方法。一种方法是误导 线粒体运动/适配器复合物与过氧化物酶体的结合，以便可以对复合物进行组装和调节 研究并突变远离内源线粒体蛋白。另一种新方法是使用 异二聚化剂将组成型活性驱动蛋白马达附着到线粒体上，从而测试是否 线粒体被锚主动固定到位。此外，该提案还引入了两个新的 控制线粒体运动的因素，线粒体是一种将线粒体固定在肌动蛋白细胞骨架上的蛋白质， 以及调节突触线粒体定位的激酶。在目标 1 中，我们建议研究如何 Miro的GTPase结构域调节复合物的组装能力及有何生理意义 这与 GTP 酶活性有关。在目标 2 中，我们研究了关于如何升高 Ca2+ 和 PINK1/Parkin 通路导致线粒体停止并询问它们是否用 锚定蛋白。在目标 3 中，我们研究了 Aurora 激酶 B 抑制线粒体的机制 运动，从而促进线粒体定位到突触。