Tomanov Konstantin, Ziba Ionida, Bachmair Andreas
Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, Dr. Bohr Gasse 9, 1030, Vienna, Austria.
Methods Mol Biol. 2016;1450:97-105. doi: 10.1007/978-1-4939-3759-2_8.
SUMO conjugation is a conserved process of eukaryotes, and essential in metazoa. Different isoforms of SUMO are present in eukaryotic genomes. Saccharomyces cerevisiae has only one SUMO protein, humans have four and Arabidopsis thaliana has eight, the main isoforms being SUMO1 and SUMO2 with about 95 % identity. Functionally similar to human SUMO2 and SUMO3, Arabidopsis SUMO1 and 2 can form chains, even though they do not possess a consensus SUMOylation motif. The surprising finding that plants have dedicated enzymes for chain synthesis implies a specific role for SUMO chains in plants. By the cooperative action with SUMO chain recognizing ubiquitin ligases, chains might channel substrates into the ubiquitin-dependent degradation pathway.A method is described to generate SUMO chains, using plant enzymes produced in E. coli. In vitro SUMO chain formation may serve for further analysis of SUMO chain functions. It can also provide an easy-to-synthesize substrate for SUMO-specific proteases.
SUMO 缀合是真核生物中一个保守的过程，在后生动物中至关重要。真核生物基因组中存在不同的 SUMO 亚型。酿酒酵母只有一种 SUMO 蛋白，人类有四种，拟南芥有八种，主要亚型是 SUMO1 和 SUMO2，它们的同一性约为 95%。拟南芥 SUMO1 和 SUMO2 在功能上与人类 SUMO2 和 SUMO3 相似，即使它们不具有一致的 SUMO 化基序，也能形成链。植物具有用于链合成的专用酶这一惊人发现意味着 SUMO 链在植物中具有特定作用。通过与识别 SUMO 链的泛素连接酶协同作用，链可能会将底物导向泛素依赖性降解途径。本文描述了一种使用大肠杆菌中产生的植物酶来生成 SUMO 链的方法。体外 SUMO 链形成可用于进一步分析 SUMO 链的功能。它还可以为 SUMO 特异性蛋白酶提供易于合成的底物。
