Mechanism of Sonic hedgehog-induced axon growth and guidance

声波刺猬诱导轴突生长和引导的机制

• 批准号: 7391158
• 负责人: Adrianne Lynn Kolpak
• 金额: $ 2.72万
• 依托单位: UNIV OF MASSACHUSETTS MED SCH WORCESTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-01-12 至 2010-01-11
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7391158
• 关键词: Affect; Antibodies; Autistic Disorder; Axon; Binding; Binding Proteins; Biological Models; Brain; Co-Immunoprecipitations; Cues; Cytoplasmic Tail; Development; Epilepsy; Erinaceidae; Genetic Transcription; Growth; Laboratories; Lead; Mediating; Membrane; Messenger RNA; Mission; Molecular; Nerve; Nervous System Physiology; Neurons; Numbers; Process; Proteins; Receptor Signaling; Regulation; Reporting; Research; Retinal Ganglion Cells; Signal Pathway; Signal Transduction; Signaling Protein; Sonic hedgehog protein; Spinal cord injury; System; Yeasts; axon growth; axon guidance; expression cloning; human SMO protein; intracellular protein transport; nervous system disorder; neural circuit; novel; protein localization location; receptor; research study; response; smoothened signaling pathway; therapy development; yeast two hybrid system

The objective of this proposal is to understand the mechanism by which the protein, Sonic hedgehog (Shh), acts in a concentration-dependent manner to regulate retinal ganglion cell axon growth and guidance. Specifically, the receptor(s) to which Shh binds will be investigated to determine if the response to both low and high concentrations of Shh is mediated by one receptor or two different receptors, which has been reported for the concentration-dependent response of axons to the guidance factor, Wnt3. A co- immunoprecipitation experiment will be performed using tagged Shh protein to identify all candidate receptors to which Shh binds on axons. Expression of candidate receptors on axons will be investigated followed by functional studies to determine if the receptorsare required for the growth response of axons to Shh. Proteins that interact with the Shh signaling protein, Smoothened (Smo), will also be investigated. It has been shown that Smo is required for transducing the axon growth responses at both low and high concentrations and Smo binding proteins are required for transducing the hedgehog signal in other systems. To identify binding partners in axons, co-immunoprecipitation experiments using an anti-Smo antibody and a yeast two-hybrid screen using the cytoplasmic tail of Smo as bait will be performed. Examining Shh signaling at both the receptor and downstreamsignaling levels will lead to a better understanding of the molecular mechanisms by which Shh affects axon growth in a concentration-dependent manner and, more generally, how axon guidance factors may direct axongrowth. Overall, the proposed research relates to the mission of the NINDS in that it will lead to a better understanding of how the neural circuitry is established during development, a process that is critical for all neurological functions. Also, it may aid in the development of therapies for spinal cord injuries, in which axons are irreparably damaged, and lead to a better understanding of neurological disorders that may result from abnormal circuit formation, including epilepsy and autism. Understanding the mechanisms that regulate axon growth during development will be important in developing therapies for spinal cord injuries, in which nerve connections are damaged and for which there is currently no cure. Also, it has been suggested that some neurological disorders, including autism and epilepsy, may result from abnormal circuit formation during brain development. Therefore, researching how axons grow will be critical for identifying the causes of some neurological disorders and in developing a cure for people with debilitating spinal cord injuries.

这项建议的目的是了解蛋白质，刺猬索尼克的机制， (Shh)以浓度依赖性方式调节视网膜神经节细胞轴突生长和导向。 具体而言，将研究Shh结合的受体以确定对两者的应答是否低。 高浓度的Shh是由一种受体或两种不同的受体介导的， 报告了轴突对导向因子Wnt 3的浓度依赖性反应。一个共同的- 将使用标记Shh蛋白进行免疫沉淀实验以鉴定所有候选物 Shh在轴突上的受体。将研究候选受体在轴突上的表达 随后进行功能研究，以确定轴突的生长反应是否需要受体， 嘘与Shh信号蛋白Smoothened（Smo）相互作用的蛋白质也将被研究。它 已经表明Smo是转导低和高浓度下轴突生长反应所必需的。 在其他系统中，转导hedgehog信号需要高浓度和Smo结合蛋白。 为了鉴定轴突中的结合伴侣，使用抗Smo抗体和抗Smo抗体的共免疫沉淀实验。 使用Smo的胞质尾作为诱饵进行酵母双杂交筛选。检查嘘 在受体和下游信号水平的信号传导将导致更好地理解 Shh以浓度依赖性方式影响轴突生长的分子机制， 一般来说，轴突导向因子如何引导轴突生长。 总的来说，拟议的研究与NINDS的使命有关，因为它将导致更好的 了解神经回路在发育过程中是如何建立的，这是一个对所有人都至关重要的过程。 神经功能。此外，它可能有助于开发脊髓损伤的治疗方法，其中 轴突受到不可修复的损伤，并导致更好地了解可能导致的神经系统疾病， 包括癫痫和自闭症。 了解在发育过程中调节轴突生长的机制将是重要的， 开发脊髓损伤的治疗方法，其中神经连接受损， 目前没有治愈。此外，有人提出，一些神经系统疾病，包括自闭症和 癫痫，可能是由于大脑发育过程中异常的回路形成。因此，研究如何 轴突的生长对于确定某些神经系统疾病的原因和开发治疗方法至关重要 对于脊髓损伤的人来说。