title: Proteomic analysis of SUMO4 substrates in HEK293 cells under serum starvation-induced stress.
abstract: The substrates of SUMO4, a novel member for the SUMO gene family, were characterized in HEK293 cells cultured under serum starvation by proteomic analysis. We identified 90 SUMO4 substrates including anti-stress proteins such as antioxidant enzymes and molecular chaperones or co-chaperones. The substrates also include proteins involved in the regulation of DNA repair and synthesis, RNA processing, protein degradation, and glucose metabolism. Several SUMO4-associated transcription factors were characterized by Western blot analyses. AP-1 was selected for in vitro conjugation assays to confirm SUMO4 sumoylation of these transcription factors. Further functional analyses of the transcription factors suggested that SUMO4 sumoylation represses AP-1 and AP-2alpha transcriptional activity, but enhances GR DNA binding capacity. These results demonstrate that SUMO4 sumoylation may play an important role in the regulation of intracellular stress.
authors.affiliation: Center for Biotechnology and Genomic Medicine, Medical College of Georgia, 1120 15th Street, CA4098, Augusta, GA 30912, USA.
authors.forename: Dehuang
authors.initials: D
authors.lastname: Guo
authors.forename: Junyan
authors.initials: J
authors.lastname: Han
authors.forename: Bao-Ling
authors.initials: BL
authors.lastname: Adam
authors.forename: Nancy H
authors.initials: NH
authors.lastname: Colburn
authors.forename: Mong-Heng
authors.initials: MH
authors.lastname: Wang
authors.forename: Zheng
authors.initials: Z
authors.lastname: Dong
authors.forename: Decio L
authors.initials: DL
authors.lastname: Eizirik
authors.forename: Jin-Xiong
authors.initials: JX
authors.lastname: She
authors.forename: Cong-Yi
authors.initials: CY
authors.lastname: Wang
mesh_terms: D002460:Cell Line; D016895:Culture Media, Serum-Free / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D011485:Protein Binding; D040901:Proteomics; D016760:Proto-Oncogene Proteins c-fos / Q000235:genetics / Q000378:metabolism; D025841:Small Ubiquitin-Related Modifier Proteins / Q000378:metabolism*; D013379:Substrate Specificity; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics
chemical_list: D016895:Culture Media, Serum-Free; D016760:Proto-Oncogene Proteins c-fos; D025841:Small Ubiquitin-Related Modifier Proteins; D014157:Transcription Factors