Modification of small ubiquitin-related modifier 2 (SUMO2) by phosphoubiquitin in HEK293T cells

Dongdem, Julius T.; Dawson, Simon P.; Layfield, Robert

Abstract

Additional complexity in the post-translational modification of proteins by ubiquitin is achieved by ubiquitin phosphorylation, for example within PINK1-parkin mediated mitophagy. We performed a preliminary proteomic analysis to identify proteins differentially modified by ubiquitin in HEK293T, compared to phosphomimetic ubiquitin (Ser65Asp), and identified small ubiquitin-related modifier 2 (SUMO2) as a candidate. By transfecting SUMO2 and its C-terminal–GG deletion mutant, along with phosphomimetic ubiquitin, we confirm that ubiquitin modifies SUMO2, rather than vice versa. Further investigations revealed that transfected SUMO2 can also be conjugated by endogenous phospho-Ser65-(poly)ubiquitin in HEK293T cells, pointing to a previously unappreciated level of complexity in SUMO2 modification, and that unanchored (substrate-free) polyubiquitin chains may also be subject to phosphorylation.

Citation

Dongdem, J. T., Dawson, S. P., & Layfield, R. (2021). Modification of small ubiquitin-related modifier 2 (SUMO2) by phosphoubiquitin in HEK293T cells. Proteomics, 21(15), Article 2000234. https://doi.org/10.1002/pmic.202000234

• Journal Article Type: Article
• Acceptance Date: May 25, 2021
• Online Publication Date: Jun 4, 2021
• Publication Date: 2021-08
• Deposit Date: Jun 22, 2021
• Publicly Available Date: Jun 22, 2021
• Journal: Proteomics
• Print ISSN: 1615-9853
• Electronic ISSN: 1615-9861
• Peer Reviewed: Peer Reviewed
• Volume: 21
• Issue: 15
• Article Number: 2000234
• DOI: https://doi.org/10.1002/pmic.202000234
• Public URL: https://nottingham-repository.worktribe.com/output/5692884
• Publisher URL: https://analyticalsciencejournals.onlinelibrary.wiley.com/doi/full/10.1002/pmic.202000234