Abstract
DNA interstrand crosslinks (ICLs) are cytotoxic lesions that threaten genome integrity. The Fanconi anemia (FA) pathway orchestrates ICL repair during DNA replication, with ubiquitylated FANCI-FANCD2 (ID2) marking the activation step that triggers incisions on DNA to unhook the ICL. Restoration of intact DNA requires the coordinated actions of polymerase ζ (Polζ)-mediated translesion synthesis (TLS) and homologous recombination (HR). While the proteins mediating FA pathway activation have been well characterized, the effectors regulating repair pathway choice to promote error-free ICL resolution remain poorly defined. Here, we uncover an indispensable role of SCAI in ensuring error-free ICL repair upon activation of the FA pathway. We show that SCAI forms a complex with Polζ and localizes to ICLs during DNA replication. SCAI-deficient cells are exquisitely sensitive to ICL-inducing drugs and display major hallmarks of FA gene inactivation. In the absence of SCAI, HR-mediated ICL repair is defective, and breaks are instead re-ligated by polymerase θ-dependent microhomology-mediated end-joining, generating deletions spanning the ICL site and radial chromosomes. Our work establishes SCAI as an integral FA pathway component, acting at the interface between TLS and HR to promote error-free ICL repair.
Originalsprog | Engelsk |
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Artikelnummer | e53639 |
Tidsskrift | EMBO Reports |
Vol/bind | 23 |
Udgave nummer | 4 |
Antal sider | 20 |
ISSN | 1469-221X |
DOI | |
Status | Udgivet - 2022 |
Bibliografisk note
Funding Information:We thank Daniel Durocher, Christine Canman, Jakob Nilsson, Alan Lehmann, Johannes Walter, and Puck Knipscheer for providing reagents, members of the Duxin and Mailand laboratories for helpful discussions, and Markus Räschle for preparation of Fig EV3A . This work was supported by grants from Novo Nordisk Foundation (grants no. NNF14CC0001, NNF16CC0020906, NNF19OC0055203, and NNF18OC0030752), Lundbeck Foundation (grant no. R223‐2016‐281), Independent Research Fund Denmark (grant no. 7016‐00055B), European Research Council (grants no. 616236‐DDRegulation and 715975‐DPC_REPAIR), European Commission's Horizon 2020 Research and Innovation Programme (Marie Skłodowska‐Curie Innovative Training Networks agreement no. 859853 (Antihelix)), and Danish National Research Foundation (grant no. DNRF115). We thank Magali Michaut and the DanStem Genomics Platform for technical support and use of instruments. Data processing and analysis were performed using the DeiC National Life Science Supercomputer at DTU ( www.computerome.dk ).
Publisher Copyright:
© 2022 The Authors. Published under the terms of the CC BY NC ND 4.0 license