Wei Wenzhong, Yang Ping, Pang Junfeng, Zhang Shu, Wang Ying, Wang Mong-Heng, Dong Zheng, She Jin-Xiong, Wang Cong-Yi
Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, CA4098, Augusta, GA 30912, USA.
Biochem Biophys Res Commun. 2008 Oct 24;375(3):454-9. doi: 10.1016/j.bbrc.2008.08.028. Epub 2008 Aug 15.
Here we performed studies to demonstrate SUMO4 maturation process. Unlike other SUMO proteins, cells under physiological condition mediate a rapid degradation for SUMO4. However, when cells under stressed condition, SUMO4 can be matured by the stress-induced endogenous hydrolase and be able to covalently conjugate to its substrate proteins. Furthermore, we failed to obtain evidence supporting a role for proline-90 unique to SUMO4 in its activation and functionality. Both wild-type SUMO4 and SUMO4-P90Q can be hydrolyzed by the stressed RAW264.7 cell lysates, and no significant functional difference between SUMO4, SUMO4-P90Q, and SUMO4-GG (matured form) was observed as determined by luciferase assay. However, the C-terminal di-glycine motif, a prerequisite for sumoylation, is necessary for SUMO4 to exert its functional activity. These data not only confirmed our previous published data, but also provided additional evidence suggesting a role for SUMO4 sumoylation in the regulation of intracellular stress.
在此，我们进行了多项研究以证明SUMO4的成熟过程。与其他SUMO蛋白不同，在生理条件下细胞会介导SUMO4的快速降解。然而，当细胞处于应激状态时，SUMO4可被应激诱导的内源性水解酶成熟，并能够与底物蛋白共价结合。此外，我们未能获得证据支持SUMO4特有的脯氨酸90在其激活和功能中发挥作用。野生型SUMO4和SUMO4-P90Q均可被应激的RAW264.7细胞裂解物水解，并且通过荧光素酶测定法未观察到SUMO4、SUMO4-P90Q和SUMO4-GG（成熟形式）之间存在显著功能差异。然而，C末端双甘氨酸基序是SUMO化的先决条件，对于SUMO4发挥其功能活性是必需的。这些数据不仅证实了我们之前发表的数据，还提供了额外的证据表明SUMO4 SUMO化在细胞内应激调节中发挥作用。
