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BRCA1 Recruitment to Transcriptional Pause Sites Is Required for R-Loop-Driven DNA Damage Repair

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...

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Detalles Bibliográficos
Autores principales: 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., Livingston, David M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Cell Press 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4351672/
https://www.ncbi.nlm.nih.gov/pubmed/25699710
http://dx.doi.org/10.1016/j.molcel.2015.01.011
Descripción
Sumario: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.