Kono Kazuteru, Harano Yumi, Hoshino Hideto, Kobayashi Masao, Bazett-Jones David P, Muto Akihiko, Igarashi Kazuhiko, Tashiro Satoshi
Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Kasumi 1-2-3, Minamiku, Hiroshima 734-8553, Japan.
Exp Cell Res. 2008 Feb 15;314(4):903-13. doi: 10.1016/j.yexcr.2007.12.013. Epub 2007 Dec 23.
The small ubiquitin-like modifier-1 (SUMO-1) modulates the functions of nuclear proteins by changing their structure and/or subnuclear localization. Several nuclear proteins form dynamic higher order nuclear structures, termed non-chromatin nuclear domains, which are involved in the regulation of nuclear function. However, the role that SUMO modification of the component proteins plays in the regulation of the activity and function of nuclear domains is unclear. Here we demonstrate that nuclear domains formed by Bach2, a transcription repressor, show restricted movement and undergo fusion events upon oxidative stress. Mutation of the SUMO-acceptor lysines in Bach2 alters the behavior of these nuclear foci and results in a decreased frequency of fusion events. We propose that SUMO modification is an important regulatory system for the mobility of the nuclear domains formed by Bach2.
小泛素样修饰物1（SUMO-1）通过改变核蛋白的结构和/或亚核定位来调节其功能。几种核蛋白形成动态的高阶核结构，称为非染色质核结构域，它们参与核功能的调节。然而，组成蛋白的SUMO修饰在核结构域的活性和功能调节中所起的作用尚不清楚。在这里，我们证明由转录抑制因子Bach2形成的核结构域显示出受限的移动性，并在氧化应激时发生融合事件。Bach2中SUMO受体赖氨酸的突变改变了这些核灶的行为，并导致融合事件的频率降低。我们提出，SUMO修饰是Bach2形成的核结构域移动性的重要调节系统。
