The Shu complex prevents mutagenesis and cytotoxicity of single-strand specific alkylation lesions
- University of Pittsburgh School of Medicine, United States
- Washington State University, United States
- Washington University in St Louis, United States
- University of North Carolina Chapel Hill, United States
Abstract
Three-methyl cytosine (3meC) are toxic DNA lesions, blocking base pairing. Bacteria and humans, express members of the AlkB enzymes family, which directly remove 3meC. However, other organisms, including budding yeast, lack this class of enzymes. It remains an unanswered evolutionary question as to how yeast repairs 3meC, particularly in single-stranded DNA. The yeast Shu complex, a conserved homologous recombination factor, aids in preventing replication-associated mutagenesis from DNA base damaging agents such as methyl methanesulfonate (MMS). We found that MMS-treated Shu complex-deficient cells, exhibit a genome-wide increase in A:T and G:C substitutions mutations. The G:C substitutions displayed transcriptional and replicational asymmetries consistent with mutations resulting from 3meC. Ectopic expression of a human AlkB homolog in Shu-deficient yeast rescues MMS-induced growth defects and increased mutagenesis. Thus, our work identifies a novel homologous recombination-based mechanism mediated by the Shu complex for coping with alkylation adducts.
Data availability
All unique mutations identified by DNA sequencing are reported in Supplemental Table 3 and all sequencing reads are reported in Supplemental Table 5. Raw sequencing reads in fastq format have been submitted to the NCBI short read archive under BioProject accession number PRJNA694993.
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Raw sequencing reads in fastq formatNCBI BioProject, PRJNA694993.
Article and author information
Author details
Adeola A Fagunloye
Funding
National Institutes of Health (ES030335)
- Kara A Bernstein
National Institutes of Health (CA218112)
- Steven Roberts
American Cancer Society (129182-RSG-16-043-01-DMC)
- Kara A Bernstein
American Cancer Society (133947-PF-19-132-01-DMC)
- Sarah R Hengel
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2021, Bonilla et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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The Shu complex prevents mutagenesis and cytotoxicity of single-strand specific alkylation lesions
eLife 10:e68080.
https://doi.org/10.7554/eLife.68080
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