YAP调控器官发育及稳态维持的分子机制研究

The control of organ size during development is a fascinating biological problem. The Hippo pathway has emerged as an evolutionarily conserved signaling pathway that controls organ size during animal development. It regulates tissue growth by balancing cell proliferation and apoptosis, and has also been implicated in stem cell maintenance, tissue homeostasis and repair. Accumulating evidence has suggested that mutations and malfunctions of Hpo pathway components lead to a wide range of human cancers and diseases. YAP, as a crucial transcriptional co-activator, is regulated by the core kinase cascade of Hippo signaling. Dysfunction of YAP disrupts tissue growth and homeostasis, leading to tumorigenesis. The cytoplasmic-nuclear shuttle of YAP protein is one of the major ways to regulate YAP’s activity and hence reflect the activity of Hippo signaling. However, the regulatory mechanisms of the cytoplasmic-nuclear shuffle of YAP protein remain obscure. By monitoring the localization change of YAP, we aim to identify genes or proteins that participate in the regulatory mechanisms of YAP cytoplasmic-nuclear shuffle using genome-scale siRNA screening and compound screening. By further studies using Drosophila and mouse models, we will further explore the related signaling mechanisms and biological functions of Hippo signaling to aid the identification and development of small molecules with the potential to serve as a rich foundation for drug discovery.

器官发育过程中的大小调控及稳态维持，一直是发育生物学的不解之谜。Hippo信号通路是近年来发现的肿瘤抑制信号通路，通过协调细胞的生长、增殖和凋亡控制器官发育的大小，并与细胞稳态维持及肿瘤发生密切相关。转录辅因子YAP作为Hippo信号通路下游的主要效应因子，其活性可以作为经典Hippo信号通路活性的标志。YAP的活性决定于其在细胞内的核质定位，但迄今为止，人们对YAP核质穿梭的调控机制只有初步的认识，缺乏深入了解，本项目将利用高内涵、高通量体系进行全基因组siRNA文库和化合物库筛选鉴定影响细胞内YAP核质定位的基因及小分子化合物，并利用Hippo相关动物模型进行机制研究和功能鉴定。此项工作旨在揭示与进一步阐明调控YAP活性的分子网络及其与Hippo信号相互作用的分子机制，不仅有助于我们理解器官形成及其稳态调控的分子机理，而且能发掘新的潜在药物，具有极其重要的科学意义与应用价值。

组织器官的发育以及损伤后修复再生是最复杂的生物学过程之一，组织器官是如何感知并响应信号，协调细胞生长、增殖和凋亡控制器官发育及组织再生是最基础和重要的发育生物学问题。Hippo信号通路是近年来发现的肿瘤抑制信号通路，通过协调细胞的生长、增殖和凋亡控制器官发育的大小，并与细胞稳态维持及肿瘤发生密切相关。转录辅因子YAP作为Hippo信号通路下游的主要效应因子，其活性可以作为经典Hippo信号通路活性的标志。我们利用人全基因组SMARTpool siRNA文库，建立了以YAP核质定位和蛋白质水平为检测标志的高通量筛选方法来鉴定Hippo-YAP的调控因子。然后利用生化、细胞手段对候选基因、小分子化合物和Hippo靶基因进行机制分析和初步的功能鉴定，进而结合果蝇和小鼠动物模型验证其在体内的功能以及与Hippo 信号的关系；尤其针对具有生物活性的小分子化合物，将结合靶蛋白的功能分析结果，进行相应的化学、生物学和药理学分析并进行改造，同时检测其在生化、细胞以及动物水平的功能。在本项目资助下，这几年我们获得了一系列优秀的研究成果。