Proteomic analysis of SUMO4 substrates in HEK293 cells under serum starvation-induced stress

• Published in: Biochemical and biophysical research communications 2005-12, Vol.337 (4), p.1308-1318
• Main Authors: Guo, Dehuang, Han, Junyan, Adam, Bao-Ling, Colburn, Nancy H., Wang, Mong-Heng, Dong, Zheng, Eizirik, Decio L., She, Jin-Xiong, Wang, Cong-Yi
• Format: Article
• Language: English
• Subjects: 2D PAGE; Cell Line; Culture Media, Serum-Free - pharmacology; Gene Expression Regulation - drug effects; H 2O 2; Humans; MALDI-TOF; Protein Binding; Proteomics; Proto-Oncogene Proteins c-fos - genetics; Proto-Oncogene Proteins c-fos - metabolism; ROS; Small Ubiquitin-Related Modifier Proteins - metabolism; Stress; Substrate; Substrate Specificity; SUMO; Sumoylation; Transcription Factors - genetics; Transcription Factors - metabolism; Transcription, Genetic - drug effects; Transcription, Genetic - genetics; Ubiquitylation
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/j.bbrc.2005.09.191

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-2α 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.