title: Caffeine suppresses homologous recombination through interference with RAD51-mediated joint molecule formation.
abstract: Caffeine is a widely used inhibitor of the protein kinases that play a central role in the DNA damage response. We used chemical inhibitors and genetically deficient mouse embryonic stem cell lines to study the role of DNA damage response in stable integration of the transfected DNA and found that caffeine rapidly, efficiently and reversibly inhibited homologous integration of the transfected DNA as measured by several homologous recombination-mediated gene-targeting assays. Biochemical and structural biology experiments revealed that caffeine interfered with a pivotal step in homologous recombination, homologous joint molecule formation, through increasing interactions of the RAD51 nucleoprotein filament with non-homologous DNA. Our results suggest that recombination pathways dependent on extensive homology search are caffeine-sensitive and stress the importance of considering direct checkpoint-independent mechanisms in the interpretation of the effects of caffeine on DNA repair.
authors.affiliation: Department of Cell Biology and Genetics, Cancer Genomics Center, Erasmus Medical Center, PO Box 2040, 3000 CA, Rotterdam, The Netherlands.
authors.forename: Alex N
authors.initials: AN
authors.lastname: Zelensky
authors.forename: Humberto
authors.initials: H
authors.lastname: Sanchez
authors.forename: Dejan
authors.initials: D
authors.lastname: Ristic
authors.forename: Iztok
authors.initials: I
authors.lastname: Vidic
authors.forename: Sari E
authors.initials: SE
authors.lastname: van Rossum-Fikkert
authors.forename: Jeroen
authors.initials: J
authors.lastname: Essers
authors.forename: Claire
authors.initials: C
authors.lastname: Wyman
authors.forename: Roland
authors.initials: R
authors.lastname: Kanaar
mesh_terms: D000818:Animals; D002110:Caffeine / Q000494:pharmacology*; D002460:Cell Line; D018390:Gene Targeting; D051379:Mice; D009698:Nucleoproteins / Q000378:metabolism / Q000648:ultrastructure; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D051135:Rad51 Recombinase / Q000037:antagonists & inhibitors* / Q000187:drug effects; D059767:Recombinational DNA Repair / Q000187:drug effects*
chemical_list: D009698:Nucleoproteins; D047428:Protein Kinase Inhibitors; D002110:Caffeine; D051135:Rad51 Recombinase