Stepwise requirements for polymerases δ and θ in theta-mediated end joining

Susanna Stroik, Juan Carvajal-Garcia, Dipika Gupta, Alyssa Edwards, Adam Luthman, David W. Wyatt, Rachel L. Dannenberg, Wanjuan Feng, Thomas A. Kunkel, Gaorav P. Gupta, Mark Hedglin, Richard Wood, Sylvie Doublié, Eli Rothenberg and Dale A. Ramsden ()
Additional contact information
Susanna Stroik: University of North Carolina at Chapel Hill
Juan Carvajal-Garcia: Vanderbilt University
Dipika Gupta: New York University School of Medicine
Alyssa Edwards: University of North Carolina at Chapel Hill
Adam Luthman: University of North Carolina at Chapel Hill
David W. Wyatt: University of North Carolina at Chapel Hill
Rachel L. Dannenberg: The Pennsylvania State University
Wanjuan Feng: University of North Carolina at Chapel Hill
Thomas A. Kunkel: National Institutes of Health
Gaorav P. Gupta: University of North Carolina at Chapel Hill
Mark Hedglin: The Pennsylvania State University
Richard Wood: The University of Texas MD Anderson Cancer Center and The University of Texas MD Anderson Cancer Center UT Health Graduate School of Biomedical Sciences
Sylvie Doublié: University of Vermont
Eli Rothenberg: New York University School of Medicine
Dale A. Ramsden: University of North Carolina at Chapel Hill

Nature, 2023, vol. 623, issue 7988, 836-841

Abstract: Abstract Timely repair of chromosomal double-strand breaks is required for genome integrity and cellular viability. The polymerase theta-mediated end joining pathway has an important role in resolving these breaks and is essential in cancers defective in other DNA repair pathways, thus making it an emerging therapeutic target1. It requires annealing of 2–6 nucleotides of complementary sequence, microhomologies, that are adjacent to the broken ends, followed by initiation of end-bridging DNA synthesis by polymerase θ. However, the other pathway steps remain inadequately defined, and the enzymes required for them are unknown. Here we demonstrate requirements for exonucleolytic digestion of unpaired 3′ tails before polymerase θ can initiate synthesis, then a switch to a more accurate, processive and strand-displacing polymerase to complete repair. We show the replicative polymerase, polymerase δ, is required for both steps; its 3′ to 5′ exonuclease activity for flap trimming, then its polymerase activity for extension and completion of repair. The enzymatic steps that are essential and specific to this pathway are mediated by two separate, sequential engagements of the two polymerases. The requisite coupling of these steps together is likely to be facilitated by physical association of the two polymerases. This pairing of polymerase δ with a polymerase capable of end-bridging synthesis, polymerase θ, may help to explain why the normally high-fidelity polymerase δ participates in genome destabilizing processes such as mitotic DNA synthesis2 and microhomology-mediated break-induced replication3.

Date: 2023
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/s41586-023-06729-7 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:623:y:2023:i:7988:d:10.1038_s41586-023-06729-7

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/s41586-023-06729-7

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().