依赖泛素及类泛素蛋白的翻译后修饰已经被证实参与几乎所有细胞内的调控过程，这些细胞事件包括转录调控、DNA损伤修复、信号转导、细胞凋亡以及细胞周期调控等。近年来随着原核生物和古细菌的类泛素家族蛋白的发现，对该家族蛋白的结构和功能有了许多新的认识，同时也提出了更多需要探索的问题。本项目将围绕着类泛素家族蛋白NEDD8,SUMO,Pup和SAMPs的结构和功能开展相关的研究。重点研究真核生物锥体虫NEDD8和SUMO系统的分子作用机制及其在细胞内的功能；原核生物Pup的构象及其和底物识别中的构象变化；以及古细菌SAMPs的结构及其分子作用机制。通过对从真核生物，原核生物到古细菌的类泛素家族蛋白的全面系统的研究，从而深入了解类泛素家族蛋白的结构和功能及其演化发展。

Ubiquitin and ubiquitin-like dependent post-translational modifications have been comfirmed to be invovled in diverse biological processes, including transcriptional regulation, DNA damage repair, signal transduction, apoptosis and cell cycle regulation, etc. In recent years, the discovery of ubiquitin-like family proteins from prokaryote and archaea brings us a lot of novel knowledge of the structure and function of this family proteins, and raises more issues to be explored as well. In this project, we will study the structure and function of ubiquitin-like family proteins NEDD8, SUMO, Pup and SAMPs. We will focus on the molecular mechanism of NEDD8 and SUMO system and their cellular functions in eukaryotic organism Trypanosoma brucei; the conformation of prokaryotic Pup and its conformational transition upon substrate binding; and the structure of archaeal SAMPs and their moleuclar mechanism. By comprehensive and systematic study of these ubiquitin-like family proteins from eukaryote, prokaryote to archaea, we can understand in depth the structure and function of ubiquitin-like family proteins and their evolution.