Breast cancer proteins PALB2 and BRCA2 stimulate polymerase η in recombination-associated DNA synthesis at blocked replication forks.
One envisioned function of homologous recombination (HR) is to find a template for DNA synthesis from the resected 3'-OH molecules that occur during double-strand break (DSB) repair at collapsed replication forks. However, the interplay between DNA synthesis and HR remains poorly understood in higher eukaryotic cells. Here, we reveal functions for the breast cancer proteins BRCA2 and PALB2 at blocked replication forks and show a role for these proteins in stimulating polymerase η (Polη) to initiate DNA synthesis. PALB2, BRCA2, and Polη colocalize at stalled or collapsed replication forks after hydroxyurea treatment. Moreover, PALB2 and BRCA2 interact with Polη and are required to sustain the recruitment of Polη at blocked replication forks. PALB2 and BRCA2 stimulate Polη-dependent DNA synthesis on D loop substrates. We conclude that PALB2 and BRCA2, in addition to their functions in D loop formation, play crucial roles in the initiation of recombination-associated DNA synthesis by Polη-mediated DNA repair.
Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada.
Rémi
R
Buisson
Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada.
Joshi
J
Niraj
Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada.
Joris
J
Pauty
Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada.
Ranjan
R
Maity
Yale University School of Medicine, New Haven, CT 06520-8024, USA.
Weixing
W
Zhao
Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada.
Yan
Y
Coulombe
Yale University School of Medicine, New Haven, CT 06520-8024, USA.
Patrick
P
Sung
Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Axis, 9 McMahon, Québec City, QC G1R 2J6, Canada; Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University, Québec City, QC G1V 0A6, Canada. Electronic address: jean-yves.masson@fmed.ulaval.ca.
Jean-Yves
JY
Masson
D024682:BRCA2 Protein / Q000378:metabolism*; D001943:Breast Neoplasms / Q000378:metabolism*; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis*; D053903:DNA Breaks, Double-Stranded; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D000076164:Fanconi Anemia Complementation Group N Protein; D005260:Female; D055785:Gene Knockdown Techniques; D006801:Humans; D018314:Leishmania infantum / Q000378:metabolism; D009687:Nuclear Proteins / Q000378:metabolism*; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D011995:Recombination, Genetic; D025521:Tumor Suppressor Proteins / Q000378:metabolism*; D000099270:Y-Family DNA Polymerases
D024682:BRCA2 Protein; D004247:DNA; D004259:DNA-Directed DNA Polymerase; D000076164:Fanconi Anemia Complementation Group N Protein; D009687:Nuclear Proteins; D025521:Tumor Suppressor Proteins; C512790:PALB2 protein, human; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases