The Coordination of Netrin Signal Transduction

Netrin信号转导的协调

• 批准号: 8179622
• 负责人: Guofa Liu
• 金额: $ 43.65万
• 依托单位: UNIVERSITY OF TOLEDO
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-01 至 2014-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8179622
• 关键词: Axon; Binding; Biochemical; Biological Assay; Brain; Cells; Cerebellum; Chick Embryo; Complex; Cues; Data; Development; Disease; Down Syndrome Cell Adhesion Molecule; Electroporation; Embryo; Embryonic Development; Family; Goals; Immunoblotting; Immunoglobulins; In Vitro; Injury; Integral Membrane Protein; Light; MAPK8 gene; Mediating; Mitogen-Activated Protein Kinases; Molecular; Mus; Nervous system structure; Neuraxis; Neurons; PTK2 gene; Phosphorylation; Play; Protein Kinase; Proteins; Rattus; Regulation; Role; Signal Transduction; Spinal; Spinal Cord; Spinal cord injury; Stroke; Subgroup; Tyrosine Phosphorylation; Vertebrates; angiogenesis; axon guidance; base; design; human NTN1 protein; member; migration; netrin receptor; netrin-1; neural circuit; neuronal guidance; receptor; research study; response; src-Family Kinases; tool; tumorigenesis

DESCRIPTION (provided by applicant): Netrins, a family of secreted proteins, are not only required for axon guidance and neuronal migration during development, but are also involved in angiogenesis and tumorigenesis. Recent studies including ours indicate that DSCAM (Down syndrome cell adhesion molecule), a transmembrane protein of the immunoglobulin superfamily, functions as a new netrin receptor required for spinal cord commissural axon outgrowth and pathfinding. This application proposes to investigate the molecular mechanisms mediating neuronal responses to netrin-1 with a focus on studying the coordination of signal transduction cascades downstream of different netrin receptors, for instance, DCC, DSCAM and UNC5. Aim 1. Determine the coordinating role of JNK1 in netrin signaling. Our preliminary results suggest that JNK1 is involved in netrin signaling. To further characterize the coordinating role of JNK1 in DCC and DSCAM downstream signaling, we plan to examine the regulation of JNK1 activity by netrin-1 in HEK293 cells and primary neurons, as well as the functional importance of JNK1 in netrin-induced axon outgrowth and attraction. Aim 2. Untangle the coordination of protein phosphorylation in netrin signaling. Protein phosphorylation plays a critical role in netrin signaling during embryonic development. To study the coordination of signal transduction cascades downstream of DSCAM and DCC, we will examine the regulation of protein phosphorylation in netrin/DSCAM signaling, the coordination of protein phosphorylation in netrin/DSCAM and netrin/DCC signaling, relationship of Src family kinases and JNK1 in netrin signal transduction cascades and the functional coordination of DSCAM and DCC in netrin-induced axon outgrowth and attraction. Aim 3. Investigate the coordination of DSCAM and UNC5 in netrin-mediated repulsion. Netrin-1 can act as an attractant or repellent in axon guidance and neuronal migration, depending on when it binds to UNC5. DSCAM forms a receptor complex with UNC5C in HEK293 cells and primary neurons, indicating that they may coordinate in netrin-mediated neuronal repulsion. We plan to examine the distribution and co-localization of DSCAM and UNC5C in the developing nervous system, the coordination of netrin/DSCAM and netrin/UNC5C downstream signaling and the functional role of DSCAM in netrin-mediating axon repulsion. These experiments will shed new light on the coordination of netrin downstream signal transduction cascades and help us better understand how the brain establishes its complex and precise wiring during development. PUBLIC HEALTH RELEVANCE: Coordination of signal transduction cascades downstream of guidance cues is crucial for neurons to find their targets and establish neural circuitry in the developing nervous system. The secreted proteins netrins are prototypical guidance cues for projecting axons and migrating neurons. Studying signal transduction of netrins will not only help us understand how the brain establishes its complex and precise wiring during development, but also provide a basis to design new strategies for injury-related diseases, such as stroke and spinal cord injuries.

描述（申请人提供）： Netrins 是一类分泌蛋白，不仅是发育过程中轴突引导和神经元迁移所必需的，而且还参与血管生成和肿瘤发生。包括我们在内的最新研究表明，DSCAM（唐氏综合症细胞粘附分子）是免疫球蛋白超家族的一种跨膜蛋白，可作为脊髓连合轴突生长和寻路所需的新 netrin 受体。本申请旨在研究介导神经元对 netrin-1 反应的分子机制，重点研究不同 netrin 受体（例如 DCC、DSCAM 和 UNC5）下游信号转导级联的协调。目标 1. 确定 JNK1 在 netrin 信号传导中的协调作用。我们的初步结果表明 JNK1 参与 netrin 信号传导。为了进一步表征 JNK1 在 DCC 和 DSCAM 下游信号传导中的协调作用，我们计划检查 HEK293 细胞和原代神经元中 netrin-1 对 JNK1 活性的调节，以及 JNK1 在 netrin 诱导的轴突生长和吸引中的功能重要性。目标 2. 解开 netrin 信号传导中蛋白质磷酸化的协调。蛋白质磷酸化在胚胎发育过程中 netrin 信号传导中起着至关重要的作用。为了研究 DSCAM 和 DCC 下游信号转导级联的协调，我们将考察 netrin/DSCAM 信号传导中蛋白磷酸化的调节、netrin/DSCAM 和 netrin/DCC 信号传导中蛋白磷酸化的协调、netrin 信号转导级联中 Src 家族激酶和 JNK1 的关系以及 DSCAM 和 DCC 信号转导级联下游的功能协调。 DCC 在 netrin 诱导的轴突生长和吸引力中的作用。目标 3. 研究 DSCAM 和 UNC5 在 netrin 介导的排斥中的协调作用。 Netrin-1 可以在轴突引导和神经元迁移中充当引诱剂或驱避剂，具体取决于它何时与 UNC5 结合。 DSCAM 与 HEK293 细胞和原代神经元中的 UNC5C 形成受体复合物，表明它们可能在 netrin 介导的神经元排斥中协调。我们计划研究 DSCAM 和 UNC5C 在发育中神经系统中的分布和共定位、netrin/DSCAM 和 netrin/UNC5C 下游信号传导的协调以及 DSCAM 在 netrin 介导的轴突排斥中的功能作用。这些实验将为 netrin 下游信号转导级联的协调提供新的线索，并帮助我们更好地了解大脑在发育过程中如何建立其复杂而精确的线路。 公共健康相关性：引导线索下游信号转导级联的协调对于神经元找到其目标并在发育中的神经系统中建立神经回路至关重要。分泌的蛋白质网络蛋白是投射轴突和迁移神经元的典型引导线索。研究netrins的信号转导不仅有助于我们了解大脑在发育过程中如何建立其复杂而精确的线路，而且还为设计针对损伤相关疾病（如中风和脊髓损伤）的新策略提供基础。