CryoEM studies of Wnt3a-FZD8-LRP6 signaling complex in neurogenesis and regeneration

WNT信号对神经元的神经发生和突触的可塑性和维持都是至关重要的。 成人的大脑。因此，调控Wnt介导的神经发生和再生是一个很有前途的研究方向。 治疗中枢神经系统损伤和神经退行性疾病，如帕金森氏症和 阿尔茨海默氏症。规范的WNT3a信号通路在与医学相关的 神经发生、再生和干细胞更新。WNT3a途径的中心事件是 WNT3a-FZD8-LRP6跨膜复合体的形成，它启动和传递来自 胞外面进入细胞膜的胞内面。缺乏结构上的信息 完整的WNT3a-FZD8-LRP6信号复合体或其同系物的任何其他复杂结构 阻碍了我们对这一基本途径的分子机制的理解，并损害了 WNT相关再生疗法的研究进展。这项研究的中心目标是确定 用单粒子低温电子显微镜研究WNT3a-FZD8-LRP6正则络合物的结构机理这个 结构研究将使我们能够可视化WNT3a配体和它的受体之间的原子相互作用 FZD8和LRP6，映射负责信号转导的关键结构元件，并识别 未来治疗分子开发的潜在位置。我们还将研究 天然来源的Wnt3a-FZD8-LRP6复合体的纯化及其配体基础的研究 选择性和专一性是该领域的一大难题，因为有多个WNT配体和 感受器。此外，我们将应用时间分辨低温电磁研究来解决信号转导问题 近乎实时的动态和可视化的WNT3a信号转导。这项研究的结果 程序不仅将作为了解其他WNT所依据的分子原理的基础 多种疾病中配体诱导的信号转导及相关病理机制 包括癌症，但也为合理设计下一代疗法铺平了道路 退行性疾病和损伤。

Wnt signaling is crucial both for neuronal neurogenesis and for synaptic plasticity and maintenance in the adult brain. Thus, modulating Wnt-mediated neurogenesis and regeneration represents a promising treatment for both central nervous system injuries and neurodegenerative diseases like Parkinson’s and Alzheimer’s. The canonical Wnt3a signaling pathway plays fundamental role in the medically relevant neurogenesis and regeneration and stem-cell renewal. The central event of the Wnt3a pathway is the formation of Wnt3a-FZD8-LRP6 transmembrane complex, which initiates and transduces the signal from the extracellular side into the intracellular side of the cell membrane. The lack of structural information on the intact Wnt3a-FZD8-LRP6 signaling complex or any other complex structure of their homologs greatly hinders our understanding of molecular mechanisms for this fundamental pathway and impairs the development of Wnt-related regenerative therapeutics. The central goal of this research is to determine the structure-based mechanisms of the canonical Wnt3a-FZD8-LRP6 complex by single particle cryo-EM. The structural study will allow us to visualize the atomic interactions between the Wnt3a ligand and its receptors FZD8 and LRP6, map key structural elements that are responsible for signal transduction, and identify potential locations for future therapeutic molecule development. We will also study the structure of the Wnt3a-FZD8-LRP6 complex that purified from native source and investigate the basis of Wnt ligand selectivity and specificity which is a great puzzle in the field considering there are multiple Wnt ligands and receptors. Additionally, we will apply time-resolved cryo-EM studies to resolve the signal transduction dynamics and visualize the Wnt3a signal transduction in near real time. The results of this research program will not only serve as a foundation for understanding the molecular principles by which other Wnt ligands induce signal transduction and related pathological mechanisms in multiple types of diseases including cancer, but also pave the way for the rational design of next-generation therapies for degenerative diseases and injuries.