UCHL3 Regulates Topoisomerase-Induced Chromosomal Break Repair by Controlling TDP1 Proteostasis
Chunyan Liao,
Ryan Beveridge,
Jessica J.R. Hudson,
Jacob D. Parker,
Shih-Chieh Chiang,
Swagat Ray,
Mohamed E. Ashour,
Ian Sudbery,
Mark J. Dickman,
Sherif F. El-Khamisy
Affiliations
Chunyan Liao
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK
Ryan Beveridge
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK
Jessica J.R. Hudson
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK; Genome Damage and Stability Centre, University of Sussex, Brighton, UK
Jacob D. Parker
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK
Shih-Chieh Chiang
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK
Swagat Ray
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK
Mohamed E. Ashour
Center for Genomics, Helmy Institute, Zewail City of Science and Technology, Giza, Egypt
Ian Sudbery
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK
Mark J. Dickman
Department of Chemical and Biological Engineering, University of Sheffield, Sheffield, UK
Sherif F. El-Khamisy
Krebs Institute, Department of Molecular Biology and Biotechnology, Firth Court, University of Sheffield, S10 2TN Sheffield, UK; Center for Genomics, Helmy Institute, Zewail City of Science and Technology, Giza, Egypt; Corresponding author
Summary: Genomic damage can feature DNA-protein crosslinks whereby their acute accumulation is utilized to treat cancer and progressive accumulation causes neurodegeneration. This is typified by tyrosyl DNA phosphodiesterase 1 (TDP1), which repairs topoisomerase-mediated chromosomal breaks. Although TDP1 levels vary in multiple clinical settings, the mechanism underpinning this variation is unknown. We reveal that TDP1 is controlled by ubiquitylation and identify UCHL3 as the deubiquitylase that controls TDP1 proteostasis. Depletion of UCHL3 increases TDP1 ubiquitylation and turnover rate and sensitizes cells to TOP1 poisons. Overexpression of UCHL3, but not a catalytically inactive mutant, suppresses TDP1 ubiquitylation and turnover rate. TDP1 overexpression in the topoisomerase therapy-resistant rhabdomyosarcoma is driven by UCHL3 overexpression. In contrast, UCHL3 is downregulated in spinocerebellar ataxia with axonal neuropathy (SCAN1), causing elevated levels of TDP1 ubiquitylation and faster turnover rate. These data establish UCHL3 as a regulator of TDP1 proteostasis and, consequently, a fine-tuner of protein-linked DNA break repair. : Deciphering the mechanisms regulating protein homeostasis is clinically important. Liao et al. identify UCHL3 as a key player in ubiquitylation and turnover of the DNA repair enzyme TDP1. Disruption of TDP1’s ubiquitylation status causes neurological disease or resistance to topoisomerase I-targeting chemotherapy in cancer. Keywords: TDP, topoisomerase, aging, neurodegeneration, cancer, rhabdosarcoma, SCAN1, heart failure, myocardial infarction, UCHL3
