title: FBH1 influences DNA replication fork stability and homologous recombination through ubiquitylation of RAD51.
abstract: Unscheduled homologous recombination (HR) can lead to genomic instability, which greatly increases the threat of neoplastic transformation in humans. The F-box DNA helicase 1 (FBH1) is a 3'-5' DNA helicase with a putative function as a negative regulator of HR. It is the only known DNA helicase to contain an F-box, suggesting that one of its functions is to act as a ubiquitin ligase as part of an SCF (SKP1, CUL1 and F-box) complex. Here we report that the central player in HR, RAD51, is ubiquitylated by the SCF(FBH1) complex. Expression of an ubiquitylation-resistant form of RAD51 in human cells leads to hyperrecombination, as well as several phenotypes indicative of an altered response to DNA replication stress. These effects are likely to be mediated by the enhanced nuclear matrix association of the ubiquitylation-resistant RAD51. These data are consistent with FBH1 acting as a negative regulator of RAD51 function in human cells.
authors.affiliation: 1] Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK [2] Center for Healthy Aging, Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
authors.forename: Wai Kit
authors.initials: WK
authors.lastname: Chu
authors.affiliation: Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK.
authors.forename: Miranda J
authors.initials: MJ
authors.lastname: Payne
authors.affiliation: Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200 Copenhagen N, Denmark.
authors.forename: Petra
authors.initials: P
authors.lastname: Beli
authors.affiliation: Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK.
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Hanada
authors.affiliation: Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, 2200 Copenhagen N, Denmark.
authors.forename: Chunaram
authors.initials: C
authors.lastname: Choudhary
authors.affiliation: 1] Weatherall Institute of Molecular Medicine, University of Oxford, John Radcliffe Hospital, Oxford OX3 9DS, UK [2] Center for Healthy Aging, Department of Cellular and Molecular Medicine, Panum Institute, University of Copenhagen, Blegdamsvej 3B, 2200 Copenhagen N, Denmark.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Hickson
mesh_terms: D000595:Amino Acid Sequence; D024682:BRCA2 Protein / Q000737:chemistry; D045744:Cell Line, Tumor; D002843:Chromatin / Q000737:chemistry; D004265:DNA Helicases / Q000737:chemistry*; D004261:DNA Replication; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004926:Escherichia coli / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000737:chemistry; D059765:Homologous Recombination; D006801:Humans; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D010641:Phenotype; D017434:Protein Structure, Tertiary; D034741:RNA, Small Interfering / Q000378:metabolism; D051135:Rad51 Recombinase / Q000737:chemistry*; D053484:RecQ Helicases / Q000737:chemistry; D011994:Recombinant Proteins / Q000737:chemistry; D011995:Recombination, Genetic; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D012568:Schizosaccharomyces / Q000378:metabolism; D054875:Ubiquitination
chemical_list: D024682:BRCA2 Protein; C551750:BRCA2 protein, human; D002843:Chromatin; D004268:DNA-Binding Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; D049452:Green Fluorescent Proteins; C495153:RAD51 protein, human; D051135:Rad51 Recombinase; C097151:Bloom syndrome protein; D004265:DNA Helicases; D053484:RecQ Helicases; C464443:FBH1 protein, human