Division of Plant and Soil Sciences, West Virginia University, Morgantown, WV 26506-6108, USA.
BMB Rep. 2010 Feb;43(2):103-9. doi: 10.5483/bmbrep.2010.43.2.103.
Modification of proteins by the reversible covalent addition of the small ubiquitin like modifier (SUMO) protein has important consequences affecting target protein stability, sub-cellular localization, and protein-protein interactions. SUMOylation involves a cascade of enzymatic reactions, which resembles the process of ubiquitination. In this study, we characterized the SUMOylation system from an important crop plant, rice, and show that it responds to cold, salt and ABA stress conditions on a protein level via the accumulation of SUMOylated proteins. We also characterized the transcriptional regulation of individual SUMOylation cascade components during stress and development. During stress conditions, majority of the SUMO cascade components are transcriptionally down regulated. SUMO conjugate proteins and SUMO cascade component transcripts accumulated differentially in various tissues during plant development with highest levels in reproductive tissues. Taken together, these data suggest a role for SUMOylation in rice development and stress responses.
蛋白质的翻译后修饰可通过可逆的共价连接小分子泛素样修饰蛋白（SUMO）来完成，该修饰对靶蛋白的稳定性、亚细胞定位和蛋白-蛋白相互作用有重要影响。SUMOylation 涉及一系列酶促反应，其过程类似于泛素化。在本研究中，我们对重要农作物水稻的 SUMOylation 系统进行了鉴定，并表明其通过 SUMO 化蛋白的积累在蛋白质水平上对冷、盐和 ABA 胁迫条件做出响应。我们还对单个 SUMOylation 级联成分在胁迫和发育过程中的转录调控进行了鉴定。在胁迫条件下，大多数 SUMO 级联成分的转录水平下调。在植物发育过程中，不同组织中 SUMO 缀合物蛋白和 SUMO 级联成分的转录本积累存在差异，在生殖组织中水平最高。总之，这些数据表明 SUMOylation 在水稻发育和应激反应中发挥作用。
