Role of msps and tacc during axon guidance

msps 和 tacc 在轴突引导过程中的作用

• 批准号: 7671458
• 负责人: Laura Anne LOWERY
• 金额: $ 4.89万
• 依托单位: HARVARD MEDICAL SCHOOL
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2011-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7671458
• 关键词: Actins; Address; Affect; Axon; Binding; Biochemical; Biological Assay; Cell Line; Cells; Cellular biology; Complex; Cues; Cytoskeletal Proteins; Cytoskeleton; Defect; Dissection; Drosophila genus; Embryonic Nervous System; Future; Genetic; Genetic Models; Genetic Screening; Goals; Growth Cones; Image; Inherited; Life; Light; Link; Logic; Malignant Neoplasms; Mediating; Microtubule-Associated Proteins; Microtubules; Modeling; Natural regeneration; Nerve Regeneration; Nervous system structure; Neurons; Ocular orbit; Pathway Analysis; Pathway interactions; Phenotype; Phosphotransferases; Play; Plus End of the Microtubule; Process; Protein Tyrosine Kinase; Proteins; Proteomics; Reporting; Research; Resolution; Role; Signal Transduction; Specificity; Testing; Therapeutic; Work; Xenopus; axon guidance; axonal pathfinding; extracellular; inhibitor/antagonist; mutant; nerve injury; nervous system development; nervous system disorder; neuron development; neuronal growth; prevent; protein protein interaction; receptor; therapy design

DESCRIPTION (provided by applicant): Accurate axon pathfinding is an essential yet highly complicated process during nervous system development. The mechanisms by which axons form complex functional neuronal networks are still a major puzzle and are relevant to understanding how abnormalities in neuronal development arise and also to nerve regeneration therapeutics. My long-term goal is to define the logic by which guidance information is integrated at the level of cytoskeletal dynamics control during axon pathfinding. As a starting point to address this issue, I will study the role of Msps and TACC, two microtubule-associated proteins which have been recently identified as suppressors of the Abl tyrosine kinase effector protein Orbit which regulates microtubule dynamics in the growth cone and mediates midline axon repulsion in the Drosophila nervous system. I will use genetic, biochemical, proteomic, and cell biological assays to investigate Msps, TACC and Orbit function in the growth cone to define the network of interactions which coordinate positive and negative microtubule dynamics during axon guidance. Specifically, I will: 1) define potential genetic pathways of interaction between Msps, TACC, and the Abl Kinase pathway (e.g. Slit, Robo, Orbit), using axonal pathfinding phenotypes in the Drosophila embryonic nervous system as an assay, testing the hypothesis that Msps and TACC function opposite of Orbit and distinguishing between possible genetic models; 2) use biochemical and proteomic analysis to determine if there are direct physical interactions between Msps/TACC, Orbit, and Abl, as well as to expand and define the Msps and TACC interaction networks involved in regulating microtubule dynamics in a Drosophila cell culture line and in neurons; and 3) define the cellular mechanisms of action of Msps and TACC, using highresolution live imaging in Xenopus growth cones. In particular, I will determine if Msps and TACC play a functionally antagonistic role to Orbit, by promoting MT extension towards the growth cone leading edge, or whether they have a different effect on MT dynamics in Xenopus growth cones. Abnormalities in axon guidance have been associated with multiple hereditary neurological disorders and thus this work may shed light on how these defects arise and possibly how to prevent them. Furthermore, mechanisms involved in axon guidance are thought to influence the ability of axons to regenerate after neural injury and so we may be able to use this information to design treatments to allow regeneration in the future. Finally, the proteins studied here are also misregulated in certain cancers. Thus, the research proposed here is of broad biomedical significance.

描述(由申请人提供)：在神经系统发育过程中，准确的轴突寻径是一个必不可少但非常复杂的过程。轴突形成复杂的功能神经网络的机制仍然是一个主要的谜团，它与理解神经元发育异常的原因有关，也与神经再生疗法有关。我的长期目标是定义在轴突寻路过程中，引导信息在细胞骨架动力学控制水平上整合的逻辑。作为解决这个问题的起点，我将研究MSPs和TACC的作用，这两个微管相关蛋白最近被发现是Abl酪氨酸激酶效应器蛋白轨道的抑制者，它调节生长锥中的微管动力学，并介导果蝇神经系统中的中线轴突排斥。我将使用遗传学、生化、蛋白质组学和细胞生物学方法来研究生长锥体中的MSPs、TACC和轨道功能，以确定在轴突引导过程中协调正负微管动力学的相互作用网络。具体地说，我将：1)定义MSPs、TACC和Abl Kinase通路(例如Sit、Robo、Orbit)之间潜在的相互作用的遗传路径，以果蝇胚胎神经系统中的轴突路径表型为基础，检验MSPs和TACC功能相反的假设，并区分可能的遗传模型；2)使用生化和蛋白质组学分析来确定MSPs/TACC、Orbit和Abl之间是否存在直接的物理相互作用，以及扩展和定义参与调控果蝇细胞系和神经元中微管动力学的MSPs和TACC相互作用网络；3)利用非洲爪哇生长锥体内的高分辨率实时成像，确定MSPs和TACC的细胞作用机制。特别是，我将确定MSPs和TACC是否通过促进MT向生长锥前沿延伸而在功能上对轨道起到拮抗作用，或者它们是否对非洲爪哇生长锥中的MT动态有不同的影响。轴突引导的异常与多种遗传性神经疾病有关，因此，这项工作可能有助于阐明这些缺陷是如何产生的，以及如何预防它们。此外，轴突引导机制被认为影响神经损伤后轴突再生的能力，因此我们可能能够利用这些信息来设计治疗方案，以允许未来的再生。最后，这里研究的蛋白质在某些癌症中也是错误调节的。因此，本文提出的研究具有广泛的生物医学意义。