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Updated: May 9, 2026

Quantitative Detection of DNA-Protein Crosslinks and Their Post-Translational Modifications
Published on: April 21, 2023
SUMOylation of damaged DNA-binding protein DDB2
Maasa Tsuge1, Yusuke Masuda, Hidenori Kaneoka
1Department of Biotechnology, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan.
Abstract:
Damaged DNA-binding protein (DDB) is a heterodimer composed of two subunits, p127 and p48, which have been designated DDB1 and DDB2, respectively. DDB2 recognizes and binds to UV-damaged DNA during nucleotide excision repair. Here, we demonstrated that DDB2 was SUMOylated in a UV-dependent manner, and its major SUMO E3 ligase was PIASy as determined by RNA interference-mediated knockdown. The UV-induced physical interaction between DDB2 and PIASy supported this notion. PIASy knockdown reduced the removal of cyclobutane pyrimidine dimers (CPDs) from total genomic DNA, but did not affect that of 6-4 pyrimidine pyrimidone photoproducts (6-4PPs). Thus, DDB2 plays an indispensable role in CPD repair, but not in 6-4PP repair, which is consistent with the observation that DDB2 was SUMOylated by PIASy. These results suggest that the SUMOylation of DDB2 facilitates CPD repair.
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