Graduate School of Life and Environmental Sciences, University of Tsukuba, Tsukuba, Japan.
Plant Signal Behav. 2009 Dec;4(12):1176-8. doi: 10.4161/psb.4.12.10044.
The conjugation of small ubiquitin-related modifier (SUMO) to substrates (sumoylation) is one of posttranslational modification systems in eukaryotes. Sumoylation plays an important role in the regulation of environmental stress response, biotic stress response, and flowering control in plants. Covalent SUMO conjugation requires an E1/E2/E3 enzyme, and SUMO E3 ligase SIZ1 is essential for these regulations. This addendum summarizes our recent study in which it has been established that in Arabidopsis, SUMO E3 ligase SIZ1 negatively controls abscisic acid (ABA) signaling through the sumoylation of ABI5. The conjugation of SUMO to ABI5 represses its activity and also prevents ABI5 from undergoing degradation.
小泛素相关修饰物（SUMO）与底物的连接（SUMOylation）是真核生物中一种翻译后修饰系统。SUMOylation 在植物的环境胁迫响应、生物胁迫响应和开花调控中发挥着重要作用。共价 SUMO 连接需要 E1/E2/E3 酶，而 SUMO E3 连接酶 SIZ1 对这些调节是必不可少的。本文增刊总结了我们最近的研究成果，即在拟南芥中，SUMO E3 连接酶 SIZ1 通过对 ABI5 的 SUMOylation 来负调控脱落酸（ABA）信号。SUMO 与 ABI5 的连接抑制其活性，并阻止 ABI5 降解。
