title: A stress-dependent SUMO4 sumoylation of its substrate proteins.
abstract: 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.
authors: Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, CA4098, Augusta, GA 30912, USA.
authors: Wenzhong
authors: W
authors: Wei
authors: Ping
authors: P
authors: Yang
authors: Junfeng
authors: J
authors: Pang
authors: Shu
authors: S
authors: Zhang
authors: Ying
authors: Y
authors: Wang
authors: Mong-Heng
authors: MH
authors: Wang
authors: Zheng
authors: Z
authors: Dong
authors: Jin-Xiong
authors: JX
authors: She
authors: Cong-Yi
authors: CY
authors: Wang
mesh_terms: D000818:Animals; D002460:Cell Line; D006801:Humans; D051379:Mice; D011392:Proline / Q000378:metabolism*; D011499:Protein Processing, Post-Translational; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: C489647:SUMO4 protein, human; D025841:Small Ubiquitin-Related Modifier Proteins; D011392:Proline