Skip to Content
MilliporeSigma
  • Senataxin Ortholog Sen1 Limits DNA:RNA Hybrid Accumulation at DNA Double-Strand Breaks to Control End Resection and Repair Fidelity.

Senataxin Ortholog Sen1 Limits DNA:RNA Hybrid Accumulation at DNA Double-Strand Breaks to Control End Resection and Repair Fidelity.

Cell reports (2020-05-07)
Chetan C Rawal, Luca Zardoni, Matteo Di Terlizzi, Elena Galati, Alessandra Brambati, Federico Lazzaro, Giordano Liberi, Achille Pellicioli
ABSTRACT

An important but still enigmatic function of DNA:RNA hybrids is their role in DNA double-strand break (DSB) repair. Here, we show that Sen1, the budding yeast ortholog of the human helicase Senataxin, is recruited at an HO endonuclease-induced DSB and limits the local accumulation of DNA:RNA hybrids. In the absence of Sen1, hybrid accumulation proximal to the DSB promotes increased binding of the Ku70-80 (KU) complex at the break site, mutagenic non-homologous end joining (NHEJ), micro-homology-mediated end joining (MMEJ), and chromosome translocations. We also show that homology-directed recombination (HDR) by gene conversion is mostly proficient in sen1 mutants after single DSB. However, in the absence of Sen1, DNA:RNA hybrids, Mre11, and Dna2 initiate resection through a non-canonical mechanism. We propose that this resection mechanism through local DNA:RNA hybrids acts as a backup to prime HDR when canonical pathways are altered, but at the expense of genome integrity.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Monoclonal ANTI-FLAG® M2 antibody produced in mouse, 1 mg/mL, clone M2, affinity isolated antibody, buffered aqueous solution (50% glycerol, 10 mM sodium phosphate, and 150 mM NaCl, pH 7.4)
Sigma-Aldrich
Nocodazole, ≥99% (TLC), powder
Millipore
Anti-FLAG® M2 Magnetic Beads, affinity isolated antibody
Sigma-Aldrich
Anti-c-Myc antibody, Mouse monoclonal, clone 9E10, purified from hybridoma cell culture
Sigma-Aldrich
Nourseothricin sulfate, ≥85% (HPLC)