title: FANCJ uses its motor ATPase to destabilize protein-DNA complexes, unwind triplexes, and inhibit RAD51 strand exchange.
abstract: Mutations in the FANCJ helicase predispose individuals to breast cancer and are genetically linked to the Fanconi anemia (FA) complementation group J. FA is a chromosomal instability disorder characterized by multiple congenital anomalies, progressive bone marrow failure, and high cancer risk. FANCJ has been proposed to function downstream of FANCD2 monoubiquitination, a critical event in the FA pathway. Evidence supports a role for FANCJ in a homologous recombination pathway of double strand break repair. In an effort to understand the molecular functions of FANCJ, we have investigated the ability of purified FANCJ recombinant protein to use its motor ATPase function for activities in addition to unwinding of conventional duplex DNA substrates. These efforts have led to the discovery that FANCJ ATP hydrolysis can be used to destabilize protein-DNA complexes and unwind triple helix alternate DNA structures. These novel catalytic functions of FANCJ may be important for its role in cellular DNA repair, recombination, or resolving DNA structural obstacles to replication. Consistent with this, we show that FANCJ can inhibit RAD51 strand exchange, an activity that is likely to be important for its role in controlling DNA repair through homologous recombination.
authors.affiliation: Laboratory of Molecular Gerontology, NIA, National Institutes of Health, National Institutes of Health Biomedical Research Center, Baltimore, Maryland 21224, USA.
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Sommers
authors.forename: Nina
authors.initials: N
authors.lastname: Rawtani
authors.forename: Rigu
authors.initials: R
authors.lastname: Gupta
authors.forename: Dmitry V
authors.initials: DV
authors.lastname: Bugreev
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Mazin
authors.forename: Sharon B
authors.initials: SB
authors.lastname: Cantor
authors.forename: Robert M
authors.initials: RM
authors.lastname: Brosh
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000235:genetics / Q000378:metabolism; D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D053903:DNA Breaks, Double-Stranded; D004260:DNA Repair / Q000502:physiology*; D004261:DNA Replication / Q000502:physiology; D051856:Fanconi Anemia Complementation Group Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D006801:Humans; D006868:Hydrolysis; D051135:Rad51 Recombinase / Q000235:genetics / Q000378:metabolism*; D011995:Recombination, Genetic / Q000502:physiology*
chemical_list: C102108:BACH1 protein, human; D050976:Basic-Leucine Zipper Transcription Factors; D051856:Fanconi Anemia Complementation Group Proteins; D000255:Adenosine Triphosphate; D004247:DNA; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; D000251:Adenosine Triphosphatases