title: The DNA damage response mediator MDC1 directly interacts with the anaphase-promoting complex/cyclosome.
abstract: MDC1 (NFBD1), a mediator of the cellular response to DNA damage, plays an important role in checkpoint activation and DNA repair. Here we identified a cross-talk between the DNA damage response and cell cycle regulation. We discovered that MDC1 binds the anaphase-promoting complex/cyclosome (APC/C), an E3 ubiquitin ligase that controls the cell cycle. The interaction is direct and is mediated by the tandem BRCA1 C-terminal domains of MDC1 and the C terminus of the Cdc27 (APC3) subunit of the APC/C. It requires the phosphorylation of Cdc27 and is enhanced after induction of DNA damage. We show that the tandem BRCA1 C-terminal domains of MDC1, known to directly bind the phosphorylated form of histone H2AX (gamma-H2AX), also bind the APC/C by the same mechanism, as phosphopeptides that correspond to the C termini of gamma-H2AX and Cdc27 competed with each other for the binding to MDC1. Our results reveal a link between the cellular response to DNA damage and cell cycle regulation, suggesting that MDC1, known to have a role in checkpoint regulation, executes part of this role by binding the APC/C.
authors.affiliation: Department of Genetics, Alexander Silberman Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel.
authors.forename: Gideon
authors.initials: G
authors.lastname: Coster
authors.forename: Zvi
authors.initials: Z
authors.lastname: Hayouka
authors.forename: Liron
authors.initials: L
authors.lastname: Argaman
authors.forename: Carmit
authors.initials: C
authors.lastname: Strauss
authors.forename: Assaf
authors.initials: A
authors.lastname: Friedler
authors.forename: Michael
authors.initials: M
authors.lastname: Brandeis
authors.forename: Michal
authors.initials: M
authors.lastname: Goldberg
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D064173:Anaphase-Promoting Complex-Cyclosome; D064191:Apc3 Subunit, Anaphase-Promoting Complex-Cyclosome; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000737:chemistry / Q000378:metabolism; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D054730:Protein Interaction Domains and Motifs; D017434:Protein Structure, Tertiary; D011839:Radiation, Ionizing; D015534:Trans-Activators / Q000737:chemistry / Q000378:metabolism*; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism*