体细胞重编程是探索细胞命运决定机制的理想平台。泛素化和类泛素化通过影响蛋白活性和稳定性在各生理病理过程具有重要功能，而在干细胞多能性获得与维持中缺乏系统认识。申请人已成功建立基于iPS小鼠的多能性研究平台，并初步发现泛素化修饰在多能性调控中发挥作用。近期研究对泛素化和类泛素化的E1酶进行功能筛选，发现NEDD8激活酶UBA3负调控iPSC形成、影响ESC多能性相关蛋白水平，进而初步分析了UBA3敲低的ESC蛋白质组和泛素化蛋白质组。基于此，拟在重编程及ESC多能性和分化中研究NEDD8修饰相关酶的功能，利用Pull-down寻找NEDD8的修饰底物，结合蛋白质组数据分析下游蛋白和通路，解析它们在重编程及ESC多能性和分化中的功能，并建立敲除小鼠模型对关键蛋白进行体内功能研究，以此构建NEDD8修饰在干细胞多能性获得与维持中的调控网络，为理解多能性调控及NEDD8修饰的作用方式提供科学依据。

The reprogramming process serves as an ideal platform for understanding cell fate decision. Ubiquitin and Ubiquitin like modifications play important roles in various biological processes via affecting the activity and stability of the targets. However, the systematical understanding of the role of ubiquitin and ubiquitin like modifications in pluripotency acquisition and maintenance is extremely lacking. We have established pluripotency research platform based on iPS mice, and noticed the importance of ubiquitin modification in pluripotency regulation. In recent studies, we performed functional screening of E1s of ubiquitin and ubiquitin-like modifications, found that UBA3 which serves as the E1 of NEDD8 negatively regulated the iPSC derivation and influence the protein level of pluripotency associated genes. Then we performed the proteome and ubiquitinated proteome analysises of Uba3 knock-down ESCs. Based on these studies, we want to further examine the function of the enzymes involved in the NEDD8 modification in reprogramming, pluripotency maintenance and differentiation, find the substrate of NEDD8 modification in ESCs using pull down, explore the downstream proteins and pathways by analyzing the substrates together with the proteome data, and then finally construct the regulation network associated with NEDD8 modification in pluripotency acquisition and maintenance. Thus, provide new clues for understanding the molecular mechanism of reprogramming and NEDD8 modification.