Identification of SUMO modification sites in the base excision repair protein, Ntg1

• Type of Material: Article
• Authors: Daniel B. Swartzlander, Emory University; Annie J. McPherson, Emory University; Harry R. Powers, Emory University; Kristin L. Limpose, Emory University; Emily G. Kuiper, Emory University; Natalya Degtyareva, Emory University; Anita Corbett, Emory University; Paul Doetsch, Emory University
• Language: English
• Date: 2016-12-01
• Publisher: Elsevier
• Publication Version: Author Accepted Manuscript (After Peer Review)
• Copyright Statement: © 2016 Elsevier B.V.
• Final Published Version (URL): http://dx.doi.org/10.1016/j.dnarep.2016.10.011
• Title of Journal or Parent Work: DNA Repair
• ISSN: 1568-7864
• Volume: 48
• Start Page: 51
• End Page: 62
• Grant/Funding Information: The content is solely the responsibility of the authors and does not necessarily reflect the official views of the National Institutes of Health.; Additional support was provided by the National Center for Advancing Translational Sciences of the National Institutes of Health under Award Number UL1TR000454.; This study was supported in part by the Emory Integrated Genomics Core (EIGC), which is subsidized by the Emory University School of Medicine and is one of the Emory Integrated Core Facilities.; This work was supported by the National Institutes of General Medical Sciences [RO1 GM05872816; T32 GM008490 22; and F31 GM115178 01] and the National Institutes of Health [NIH ES011163].
• Keywords: MOLECULAR-MECHANISMS; DYNAMIC LOCALIZATION; ENDONUCLEASE-III; THYMINE-DNA GLYCOSYLASE; Sumoylation; OXIDATIVE STRESS; MITOCHONDRIAL-DNA; Genetics & Heredity; BIOLOGICAL CONSEQUENCES; CRYSTAL-STRUCTURE; Toxicology; SUMO; Base excision repair (BER); Ntg1; NTHL1; Science & Technology; COLORECTAL-CANCER; SACCHAROMYCES-CEREVISIAE; Life Sciences & Biomedicine
• Research Categories: Health Sciences, Oncology; Biology, Genetics

Abstract

DNA damaging agents are a constant threat to genomes in both the nucleus and the mitochondria. To combat this threat, a suite of DNA repair pathways cooperate to repair numerous types of DNA damage. If left unrepaired, these damages can result in the accumulation of mutations which can lead to deleterious consequences including cancer and neurodegenerative disorders. The base excision repair (BER) pathway is highly conserved from bacteria to humans and is primarily responsible for the removal and subsequent repair of toxic and mutagenic oxidative DNA lesions. Although the biochemical steps that occur in the BER pathway have been well defined, little is known about how the BER machinery is regulated. The budding yeast, Saccharomyces cerevisiae is a powerful model system to biochemically and genetically dissect BER. BER is initiated by DNA N-glycosylases, such as S. cerevisiae Ntg1. Previous work demonstrates that Ntg1 is post-translationally modified by SUMO in response to oxidative DNA damage suggesting that this modification could modulate the function of Ntg1. In this study, we mapped the specific sites of SUMO modification within Ntg1 and identified the enzymes responsible for sumoylating/desumoylating Ntg1. Using a non-sumoylatable version of Ntg1, ntg1ΔSUMO, we performed an initial assessment of the functional impact of Ntg1 SUMO modification in the cellular response to DNA damage. Finally, we demonstrate that, similar to Ntg1, the human homologue of Ntg1, NTHL1, can also be SUMO-modified in response to oxidative stress. Our results suggest that SUMO modification of BER proteins could be a conserved mechanism to coordinate cellular responses to DNA damage.