The Fanconi anemia protein FANCM can promote branch migration of Holliday junctions and replication forks.
Fanconi anemia (FA) is a genetically heterogeneous cancer-prone disorder associated with chromosomal instability and cellular hypersensitivity to DNA crosslinking agents. The FA pathway is suspected to play a crucial role in the cellular response to DNA replication stress. At a molecular level, however, the function of most of the FA proteins is unknown. FANCM displays DNA-dependent ATPase activity and promotes the dissociation of DNA triplexes, but the physiological significance of this activity remains elusive. Here we show that purified FANCM binds to Holliday junctions and replication forks with high specificity and promotes migration of their junction point in an ATPase-dependent manner. Furthermore, we provide evidence that FANCM can dissociate large recombination intermediates, via branch migration of Holliday junctions through 2.6 kb of DNA. Our data suggest a direct role for FANCM in DNA processing, consistent with the current view that FA proteins coordinate DNA repair at stalled replication forks.
Gari
Kerstin
K
Department of Biochemistry, University of Lausanne, Ch. des Boveresses 155, 1066 Epalinges s/Lausanne, Switzerland.
Décaillet
Chantal
C
Stasiak
Alicja Z
AZ
Stasiak
Andrzej
A
Constantinou
Angelos
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000266:Adenylyl Imidodiphosphate / Q000378:metabolism; D000818:Animals; D002460:Cell Line / Q000737:chemistry; D002846:Chromatography, Affinity; D004265:DNA Helicases / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology* / Q000648:ultrastructure; D004261:DNA Replication / Q000502:physiology*; D045566:DNA, Cruciform / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000502:physiology; D019281:Dimerization; D024202:Electrophoretic Mobility Shift Assay; D051856:Fanconi Anemia Complementation Group Proteins; D006801:Humans; D008854:Microscopy, Electron; D009838:Oligodeoxyribonucleotides / Q000138:chemical synthesis / Q000378:metabolism; D011485:Protein Binding; D011993:Recombinant Fusion Proteins / Q000302:isolation & purification / Q000502:physiology; D011995:Recombination, Genetic / Q000502:physiology*; D018411:Spodoptera; D013379:Substrate Specificity
D045566:DNA, Cruciform; D004268:DNA-Binding Proteins; C518296:FAAP24 protein, human; D051856:Fanconi Anemia Complementation Group Proteins; D009838:Oligodeoxyribonucleotides; D011993:Recombinant Fusion Proteins; D000266:Adenylyl Imidodiphosphate; D000255:Adenosine Triphosphate; C518295:FANCM protein, human; D004265:DNA Helicases