MRE11-RAD50-NBS1 Complex Is Sufficient to Promote Transcription by RNA Polymerase II at Double-Strand Breaks by Melting DNA Ends.

Cell reports 2021 Jan 05

filter terms:

The MRE11-RAD50-NBS1 (MRN) complex supports the synthesis of damage-induced long non-coding RNA (dilncRNA) by RNA polymerase II (RNAPII) from DNA double-strand breaks (DSBs) by an unknown mechanism. Here, we show that recombinant human MRN and native RNAPII are sufficient to reconstitute a minimal functional transcriptional apparatus at DSBs. MRN recruits and stabilizes RNAPII at DSBs. Unexpectedly, transcription is promoted independently from MRN nuclease activities. Rather, transcription depends on the ability of MRN to melt DNA ends, as shown by the use of MRN mutants and specific allosteric inhibitors. Single-molecule FRET assays with wild-type and mutant MRN show a tight correlation between the ability to melt DNA ends and to promote transcription. The addition of RPA enhances MRN-mediated transcription, and unpaired DNA ends allow MRN-independent transcription by RNAPII. These results support a model in which MRN generates single-strand DNA ends that favor the initiation of transcription by RNAPII. Copyright © 2020 The Author(s). Published by Elsevier Inc. All rights reserved.

Citation

Sheetal Sharma, Roopesh Anand, Xuzhu Zhang, Sofia Francia, Flavia Michelini, Alessandro Galbiati, Hannah Williams, Daryl A Ronato, Jean-Yves Masson, Eli Rothenberg, Petr Cejka, Fabrizio d'Adda di Fagagna. MRE11-RAD50-NBS1 Complex Is Sufficient to Promote Transcription by RNA Polymerase II at Double-Strand Breaks by Melting DNA Ends. Cell reports. 2021 Jan 05;34(1):108565