title: Dampening DNA damage checkpoint signalling via coordinated BRCT domain interactions.
abstract: In response to DNA damage, checkpoint signalling protects genome integrity at the cost of repressing cell cycle progression and DNA replication. Mechanisms for checkpoint down-regulation are therefore necessary for proper cellular proliferation. We recently uncovered a phosphatase-independent mechanism for dampening checkpoint signalling, where the checkpoint adaptor Rad9 is counteracted by the repair scaffolds Slx4-Rtt107. Here, we establish the molecular requirements for this new mode of checkpoint regulation. We engineered a minimal multi-BRCT-domain (MBD) module that recapitulates the action of Slx4-Rtt107 in checkpoint down-regulation. MBD mimics the damage-induced Dpb11-Slx4-Rtt107 complex by synergistically interacting with lesion-specific phospho-sites in Ddc1 and H2A. We propose that efficient recruitment of Dpb11-Slx4-Rtt107 or MBD via a cooperative 'two-site-docking' mechanism displaces Rad9. MBD also interacts with the Mus81 nuclease following checkpoint dampening, suggesting a spatio-temporal coordination of checkpoint signalling and DNA repair via a combinatorial mode of BRCT-domains interactions.
authors.affiliation: Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA.
authors.forename: José R
authors.initials: JR
authors.lastname: Cussiol
authors.affiliation: Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA.
authors.forename: Carolyn M
authors.initials: CM
authors.lastname: Jablonowski
authors.affiliation: Donnelly Centre and Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Askar
authors.initials: A
authors.lastname: Yimit
authors.affiliation: Donnelly Centre and Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
authors.forename: Grant W
authors.initials: GW
authors.lastname: Brown
authors.affiliation: Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA mbs266@cornell.edu.
authors.forename: Marcus B
authors.initials: MB
authors.lastname: Smolka
mesh_terms: D015153:Blotting, Western; D059447:Cell Cycle Checkpoints / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000378:metabolism; D004249:DNA Damage / Q000502:physiology*; D016521:Electrophoresis, Gel, Pulsed-Field; D047468:Immunoprecipitation; D008954:Models, Biological; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D015202:Protein Engineering / Q000379:methods; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism*; D012441:Saccharomyces cerevisiae; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: D018797:Cell Cycle Proteins; D009687:Nuclear Proteins; C501265:RTT107 protein, S cerevisiae; D011994:Recombinant Proteins; D029701:Saccharomyces cerevisiae Proteins; C069930:rad9 protein
keywords: BRCT domain; DNA damage; Dpb11; Slx4; checkpoint