Proteomic Profiling Reveals a Specific Role for Translesion DNA Polymerase η in the Alternative Lengthening of Telomeres.
Cancer cells rely on the activation of telomerase or the alternative lengthening of telomeres (ALT) pathways for telomere maintenance and survival. ALT involves homologous recombination (HR)-dependent exchange and/or HR-associated synthesis of telomeric DNA. Utilizing proximity-dependent biotinylation (BioID), we sought to determine the proteome of telomeres in cancer cells that employ these distinct telomere elongation mechanisms. Our analysis reveals that multiple DNA repair networks converge at ALT telomeres. These include the specialized translesion DNA synthesis (TLS) proteins FANCJ-RAD18-PCNA and, most notably, DNA polymerase eta (Polη). We observe that the depletion of Polη leads to increased ALT activity and late DNA polymerase δ (Polδ)-dependent synthesis of telomeric DNA in mitosis. We propose that Polη fulfills an important role in managing replicative stress at ALT telomeres, maintaining telomere recombination at tolerable levels and stimulating DNA synthesis by Polδ.
Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Laura
L
Garcia-Exposito
CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037 Toulouse, France.
Elodie
E
Bournique
CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037 Toulouse, France.
Valérie
V
Bergoglio
Department of Environmental and Occupational Health, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Arindam
A
Bose
Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Jonathan
J
Barroso-Gonzalez
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
Sufang
S
Zhang
Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Justin L
JL
Roncaioli
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, NY 10595, USA.
Marietta
M
Lee
Department of Cell Biology, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Callen T
CT
Wallace
Department of Cell Biology, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Simon C
SC
Watkins
Department of Environmental and Occupational Health, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA.
Patricia L
PL
Opresko
CRCT, Université de Toulouse, Inserm, CNRS, UPS Equipe Labellisée Ligue Contre le Cancer, Laboratoire d'Excellence Toulouse Cancer, 2 Avenue Hubert Curien, 31037 Toulouse, France.
Jean-Sébastien
JS
Hoffmann
Department of Pharmacology and Chemical Biology, University of Pittsburgh Cancer Institute, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA. Electronic address: osullivanr@upmc.edu.
Roderick J
RJ
O'Sullivan
D019921:Biotinylation; D004247:DNA / Q000096:biosynthesis; D004258:DNA Polymerase III / Q000378:metabolism; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008938:Mitosis; D040901:Proteomics / Q000379:methods*; D059767:Recombinational DNA Repair; D016615:Telomere / Q000378:metabolism*; D059505:Telomere Homeostasis; D000099270:Y-Family DNA Polymerases
D004247:DNA; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase; C435720:POLD3 protein, human; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases
BioID; D-loop; cancer; mitosis; polymerase; telomere; translesion DNA synthesis