DNA2 drives processing and restart of reversed replication forks in human cells.
Accurate processing of stalled or damaged DNA replication forks is paramount to genomic integrity and recent work points to replication fork reversal and restart as a central mechanism to ensuring high-fidelity DNA replication. Here, we identify a novel DNA2- and WRN-dependent mechanism of reversed replication fork processing and restart after prolonged genotoxic stress. The human DNA2 nuclease and WRN ATPase activities functionally interact to degrade reversed replication forks with a 5'-to-3' polarity and promote replication restart, thus preventing aberrant processing of unresolved replication intermediates. Unexpectedly, EXO1, MRE11, and CtIP are not involved in the same mechanism of reversed fork processing, whereas human RECQ1 limits DNA2 activity by preventing extensive nascent strand degradation. RAD51 depletion antagonizes this mechanism, presumably by preventing reversed fork formation. These studies define a new mechanism for maintaining genome integrity tightly controlled by specific nucleolytic activities and central homologous recombination factors.
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104.
Saravanabhavan
S
Thangavel
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104.
Matteo
M
Berti
Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland.
Maryna
M
Levikova
Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland.
Cosimo
C
Pinto
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104.
Shivasankari
S
Gomathinayagam
Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland.
Marko
M
Vujanovic
Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland.
Ralph
R
Zellweger
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110.
Hayley
H
Moore
Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455.
Eu Han
EH
Lee
Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455.
Eric A
EA
Hendrickson
Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland.
Petr
P
Cejka
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110.
Sheila
S
Stewart
Institute of Molecular Cancer Research, University of Zurich, CH-8057 Zurich, Switzerland.
Massimo
M
Lopes
Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104 avindign@slu.edu.
Alessandro
A
Vindigni
D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002460:Cell Line; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D045643:DNA Repair Enzymes / Q000235:genetics / Q000378:metabolism; D004261:DNA Replication / Q000502:physiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases / Q000235:genetics / Q000378:metabolism; D006801:Humans; D000076228:MRE11 Homologue Protein; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism; D053484:RecQ Helicases / Q000235:genetics / Q000378:metabolism; D000071657:Werner Syndrome Helicase
D002352:Carrier Proteins; D004268:DNA-Binding Proteins; C121766:MRE11 protein, human; D009687:Nuclear Proteins; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C114331:EXO1 protein, human; D004706:Endodeoxyribonucleases; D005090:Exodeoxyribonucleases; D000076228:MRE11 Homologue Protein; C410741:RBBP8 protein, human; C506725:RECQL protein, human; D004265:DNA Helicases; C509908:DNA2 protein, human; D053484:RecQ Helicases; C098785:WRN protein, human; D000071657:Werner Syndrome Helicase; D045643:DNA Repair Enzymes