1. BRCA1 Recruitment to Transcriptional Pause Sites Is Required for R-Loop-Driven DNA Damage Repair
- Author
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Hatchi, Elodie, Skourti-Stathaki, Konstantina, Ventz, Steffen, Pinello, Luca, Yen, Angela, Kamieniarz-Gdula, Kinga, Dimitrov, Stoil, Pathania, Shailja, McKinney, Kristine M., Eaton, Matthew L., Kellis, Manolis, Hill, Sarah J., Parmigiani, Giovanni, Proudfoot, Nicholas J., and Livingston, David M.
- Abstract
Summary The mechanisms contributing to transcription-associated genomic instability are both complex and incompletely understood. Although R-loops are normal transcriptional intermediates, they are also associated with genomic instability. Here, we show that BRCA1 is recruited to R-loops that form normally over a subset of transcription termination regions. There it mediates the recruitment of a specific, physiological binding partner, senataxin (SETX). Disruption of this complex led to R-loop-driven DNA damage at those loci as reflected by adjacent γ-H2AX accumulation and ssDNA breaks within the untranscribed strand of relevant R-loop structures. Genome-wide analysis revealed widespread BRCA1 binding enrichment at R-loop-rich termination regions (TRs) of actively transcribed genes. Strikingly, within some of these genes in BRCA1 null breast tumors, there are specific insertion/deletion mutations located close to R-loop-mediated BRCA1 binding sites within TRs. Thus, BRCA1/SETX complexes support a DNA repair mechanism that addresses R-loop-based DNA damage at transcriptional pause sites.
- Published
- 2015
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