TY - JOUR

T1 - SCAI promotes error-free repair of DNA interstrand crosslinks via the Fanconi anemia pathway

AU - Schubert, Lisa

AU - Hendriks, Ivo A.

AU - Hertz, Emil P.T.

AU - Wu, Wei

AU - Sellés-Baiget, Selene

AU - Hoffmann, Saskia

AU - Viswalingam, Keerthana Stine

AU - Gallina, Irene

AU - Pentakota, Satyakrishna

AU - Benedict, Bente

AU - Johansen, Joachim

AU - Apelt, Katja

AU - Luijsterburg, Martijn S.

AU - Rasmussen, Simon

AU - Lisby, Michael

AU - Liu, Ying

AU - Nielsen, Michael L.

AU - Mailand, Niels

AU - Duxin, Julien P.

N1 - Publisher Copyright: © 2022 The Authors. Published under the terms of the CC BY NC ND 4.0 license

PY - 2022

Y1 - 2022

N2 - 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.

AB - 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.

KW - DNA interstrand crosslinks (ICLs)

KW - DNA repair

KW - DNA replication

KW - genome stability

KW - translesion DNA synthesis (TLS)

U2 - 10.15252/embr.202153639

DO - 10.15252/embr.202153639

M3 - Journal article

C2 - 35156773

AN - SCOPUS:85124540448

VL - 23

JO - E M B O Reports

JF - E M B O Reports

SN - 1469-221X

IS - 4

M1 - e53639

ER -