PARylation prevents the proteasomal degradation of topoisomerase I DNA-protein crosslinks and induces their deubiquitylation

Yilun Sun; Jiji Chen; Shar-Yin N Huang; Yijun P Su; Wenjie Wang; Keli Agama; Sourav Saha; Lisa M Jenkins; John M Pascal; Yves Pommier

doi:10.1038/s41467-021-25252-9

PARylation prevents the proteasomal degradation of topoisomerase I DNA-protein crosslinks and induces their deubiquitylation

Nat Commun. 2021 Aug 18;12(1):5010. doi: 10.1038/s41467-021-25252-9.

Authors

Affiliations

¹ Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA. yilun.sun@nih.gov.
² Advanced Imaging and Microscopy Resource, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, MD, USA.
³ Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA.
⁴ Collaborative Protein Technology Resource, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA.
⁵ Department of Biochemistry and Molecular Medicine, Université de Montréal, Montreal, QC, Canada.
⁶ Developmental Therapeutics Branch and Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD, USA. pommier@nih.gov.

Abstract

Poly(ADP)-ribosylation (PARylation) regulates chromatin structure and recruits DNA repair proteins. Using single-molecule fluorescence microscopy to track topoisomerase I (TOP1) in live cells, we found that sustained PARylation blocked the repair of TOP1 DNA-protein crosslinks (TOP1-DPCs) in a similar fashion as inhibition of the ubiquitin-proteasome system (UPS). PARylation of TOP1-DPC was readily revealed by inhibiting poly(ADP-ribose) glycohydrolase (PARG), indicating the otherwise transient and reversible PARylation of the DPCs. As the UPS is a key repair mechanism for TOP1-DPCs, we investigated the impact of TOP1-DPC PARylation on the proteasome and found that the proteasome is unable to associate with and digest PARylated TOP1-DPCs. In addition, PARylation recruits the deubiquitylating enzyme USP7 to reverse the ubiquitylation of PARylated TOP1-DPCs. Our work identifies PARG as repair factor for TOP1-DPCs by enabling the proteasomal digestion of TOP1-DPCs. It also suggests the potential regulatory role of PARylation for the repair of a broad range of DPCs.

Publication types

Research Support, N.I.H., Intramural
Research Support, Non-U.S. Gov't

MeSH terms

DNA / chemistry
DNA / genetics*
DNA / metabolism
DNA Damage
DNA Repair
DNA Topoisomerases, Type I / chemistry
DNA Topoisomerases, Type I / genetics
DNA Topoisomerases, Type I / metabolism*
Glycoside Hydrolases / genetics
Glycoside Hydrolases / metabolism
HEK293 Cells
Humans
Poly ADP Ribosylation
Proteasome Endopeptidase Complex / chemistry
Proteasome Endopeptidase Complex / genetics
Proteasome Endopeptidase Complex / metabolism*
Proteolysis
Ubiquitination

Substances

DNA
Glycoside Hydrolases
poly ADP-ribose glycohydrolase
Proteasome Endopeptidase Complex
DNA Topoisomerases, Type I
TOP1 protein, human

Abstract

Publication types

MeSH terms

Substances

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