| Autor: |
Deshpande, Rajashree A., Marin-Gonzalez, Alberto, Barnes, Hannah K., Woolley, Phillip R., Ha, Taekjip, Paull, Tanya T. |
| Předmět: |
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| Zdroj: |
Nature Communications; 9/16/2023, Vol. 14 Issue 1, p1-17, 17p |
| Abstrakt: |
The Mre11-Rad50-Nbs1 (MRN) complex recognizes and processes DNA double-strand breaks for homologous recombination by performing short-range removal of 5ʹ strands. Endonucleolytic processing by MRN requires a stably bound protein at the break site—a role we postulate is played by DNA-dependent protein kinase (DNA-PK) in mammals. Here we interrogate sites of MRN-dependent processing by identifying sites of CtIP association and by sequencing DNA-PK-bound DNA fragments that are products of MRN cleavage. These intermediates are generated most efficiently when DNA-PK is catalytically blocked, yielding products within 200 bp of the break site, whereas DNA-PK products in the absence of kinase inhibition show greater dispersal. Use of light-activated Cas9 to induce breaks facilitates temporal resolution of DNA-PK and Mre11 binding, showing that both complexes bind to DNA ends before release of DNA-PK-bound products. These results support a sequential model of double-strand break repair involving collaborative interactions between homologous and non-homologous repair complexes. Deshpande et al show that MRN nuclease-dependent processing of DNA ends in human cells occurs at sites bound by DNA-PK. Chromatin immunoprecipitation analysis of DNA-PK, MRN, and CtIP supports a sequential model of pathway choice. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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