Targeting Postsynaptic Small G-protein Regulators

摘要 这项应用旨在发现和验证RAC鸟苷核苷酸的小分子抑制剂 交换因子Kalirin，大脑皮层树突棘中的主要信号转导中心。 我们的长期目标是将有关树突棘可塑性和突触小GTP酶的知识 信号，用于神经精神障碍(NPD)的治疗。树突棘是大多数 大脑中的兴奋性突触，并在神经元回路的发展和可塑性中发挥核心作用， 最终影响到学习、记忆和行为。相反，树突棘的异常是 广泛参与NPD的发病机制。小分子GTP酶介导的分子通路，如Rac， 直接上游激活物(GEF)及其下游靶点是支配树突的主要途径 脊柱的可塑性。此外，遗传和尸检研究证明了这些途径的关键作用。 在NPDS的发病机制中起重要作用。Kalirin是大脑皮层树突棘中含量最丰富的RAC-Global 和海马体，在脊柱可塑性和病理中发挥中心作用，如击倒和 基因敲除研究，并已通过遗传学、尸检和功能研究发现与NPD有关。因此， 为了研究Kalirin在皮质可塑性和NPD发病机制中的作用，以及Rac-GTPase信号转导机制 总之，我们的目标是开发新的、有效的、特异的、具有生物活性的Kalirin抑制剂。 神经元。我们已经在突触生物学和NPD方面的专家之间建立了合作关系，高度- 吞吐量筛选和计算药理学、药物化学和结晶学，以及 进行了广泛的初步研究，证明了我们假设的正确性和可行性 我们的方法。我们提出了以下具体目标：1)通过HTS发现Hit来识别Small 与Kalirin的DHPH结构域结合并抑制其全球环境基金活性的分子。2)蜂窝中的命中验证 和神经细胞分析。3)HIT化合物作用机理的表征。4)药用 新型全环基金抑制剂的化学优化

ABSTRACT This application aims to discover and validate small-molecule inhibitors of the Rac guanosine-nucleotide exchange factor (GEF) kalirin, a major signal transduction hub in dendritic spines in the cerebral cortex. Our long-term goal is to translate knowledge about dendritic spine plasticity and synaptic small GTPase signaling, into treatments of neuropsychiatric disorders (NPDs). Dendritic spines are the sites of most excitatory synapses in the brain, and play central roles in the development and plasticity of neuronal circuits, and ultimately in learning, memory, and behavior. Conversely, abnormalities in dendritic spines are extensively involved in NPD pathogenesis. Molecular pathways mediated by small GTPases such as Rac, direct upstream activators (GEFs), and their downstream targets are major pathways that govern dendritic spine plasticity. Furthermore, genetic and postmortem studies demonstrate a key role for these pathways in the pathogenesis of NPDs. Kalirin is the most abundant Rac-GEF in dendritic spines in the cerebral cortex and hippocampus, plays central roles in spine plasticity and pathology as shown by knockdown and knockout studies, and has been implicated in NPDs by genetic, postmortem, and functional studies. Hence, in order to study the role of kalirin in cortical plasticity and NPD pathogenesis, and of Rac-GTPase signaling in general, here we aim to develop novel, potent, specific, inhibitors of kalirin with biological activity in neurons. We have established a collaboration between experts in synapse biology and NPDs, high- throughput screening and computational pharmacology, medicinal chemistry, and crystallography, and performed extensive preliminary studies that demonstrate the validity of our hypothesis and the feasibility of our approach. We propose the following Specific Aims: 1) Hit discovery by HTS to identify small molecules binding to kalirin's DHPH domain and inhibiting its GEF activity. 2) Hit validation in cellular and neuronal assays. 3) Characterization of the mechanism of action of hit compounds. 4) Medicinal chemistry optimization of new GEF inhibitors