Abstract
Posttranslational modifications by small ubiquitin-like modifiers (SUMOs) regulate many cellular processes, including genome integrity, gene expression, and ribosome biogenesis. The E2-conjugating enzyme Ubc9 catalyzes the conjugation of SUMOs to epsilon-amino groups of lysine residues in target proteins. Attachment of SUMO moieties to internal lysines in Ubc9 itself can further lead to the formation of polymeric SUMO chains. Mono-and poly-SUMOylations of target proteins provide docking sites for distinct adapter and effector proteins important for regulating discrete SUMO-regulated pathways. However, molecular tools to dissect pathways depending on either mono-or poly-SUMOylation are largely missing. Using a protein-engineering approach, we generated high-affinity SUMO2 variants by phage display that bind the back side binding site of Ubc9 and function as SUMO-based Ubc9 inhibitors (SUBINs). Importantly, we found that distinct SUBINs primarily inhibit poly-SUMO chain formation, whereas mono-SUMOylation was not impaired. Proof-of-principle experiments demonstrated that in a cellular context, SUBINs largely prevent heat shock-triggered polySUMOylation. Moreover, SUBINs abrogated arsenic-induced degradation of promyelocytic leukemia protein. We propose that the availability of the new chain-selective SUMO inhibitors reported here will enable a thorough investigation of poly-SUMO-mediated cellular processes, such as DNA damage responses and cell cycle progression.
Item Type: | Journal article |
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Faculties: | Biology > Department Biology II |
Subjects: | 500 Science > 570 Life sciences; biology |
ISSN: | 0021-9258 |
Language: | English |
Item ID: | 54687 |
Date Deposited: | 14. Jun 2018, 09:57 |
Last Modified: | 23. Dec 2020, 13:26 |