title: Dbf4-dependent kinase and the Rtt107 scaffold promote Mus81-Mms4 resolvase activation during mitosis.
abstract: DNA repair by homologous recombination is under stringent cell cycle control. This includes the last step of the reaction, disentanglement of DNA joint molecules (JMs). Previous work has established that JM resolving nucleases are activated specifically at the onset of mitosis. In case of budding yeast Mus81-Mms4, this cell cycle stage-specific activation is known to depend on phosphorylation by CDK and Cdc5 kinases. Here, we show that a third cell cycle kinase, Cdc7-Dbf4 (DDK), targets Mus81-Mms4 in conjunction with Cdc5-both kinases bind to as well as phosphorylate Mus81-Mms4 in an interdependent manner. Moreover, DDK-mediated phosphorylation of Mms4 is strictly required for Mus81 activation in mitosis, establishing DDK as a novel regulator of homologous recombination. The scaffold protein Rtt107, which binds the Mus81-Mms4 complex, interacts with Cdc7 and thereby targets DDK and Cdc5 to the complex enabling full Mus81 activation. Therefore, Mus81 activation in mitosis involves at least three cell cycle kinases, CDK, Cdc5 and DDK Furthermore, tethering of the kinases in a stable complex with Mus81 is critical for efficient JM resolution.
authors.affiliation: Max Planck Institute of Biochemistry, DNA Replication and Genome Integrity, Martinsried, Germany.
authors.forename: Lissa N
authors.initials: LN
authors.lastname: Princz
authors.affiliation: Institute of Biochemistry, Eidgenössische Technische Hochschule, Zürich, Switzerland.
authors.forename: Philipp
authors.initials: P
authors.lastname: Wild
authors.affiliation: Max Planck Institute of Biochemistry, DNA Replication and Genome Integrity, Martinsried, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Bittmann
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Research in Molecular Medicine and Chronic Diseases, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: F Javier
authors.initials: FJ
authors.lastname: Aguado
authors.affiliation: Department of Biochemistry and Molecular Biology, Center for Research in Molecular Medicine and Chronic Diseases, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: Miguel G
authors.identifier: 0000-0002-2883-7326
authors.initials: MG
authors.lastname: Blanco
authors.affiliation: Institute of Biochemistry, Eidgenössische Technische Hochschule, Zürich, Switzerland.
authors.forename: Joao
authors.initials: J
authors.lastname: Matos
authors.affiliation: Max Planck Institute of Biochemistry, DNA Replication and Genome Integrity, Martinsried, Germany bpfander@biochem.mpg.de.
authors.forename: Boris
authors.identifier: 0000-0003-2180-5054
authors.initials: B
authors.lastname: Pfander
mesh_terms: D018797:Cell Cycle Proteins / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000378:metabolism*; D004720:Endonucleases / Q000378:metabolism*; D004789:Enzyme Activation; D045585:Flap Endonucleases / Q000378:metabolism*; D008938:Mitosis; D009687:Nuclear Proteins / Q000378:metabolism*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000201:enzymology / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C501265:RTT107 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C489404:CDC7 protein, S cerevisiae; D017346:Protein Serine-Threonine Kinases; C081927:CDC5 protein, S cerevisiae; D004720:Endonucleases; D045585:Flap Endonucleases; C411624:MUS81 protein, S cerevisiae; C112337:MMS4 protein, S cerevisiae
keywords: cell cycle; genome stability; homologous recombination; joint molecule resolution; post‐translational modification