title: ZTF-8 interacts with the 9-1-1 complex and is required for DNA damage response and double-strand break repair in the C. elegans germline.
abstract: Germline mutations in DNA repair genes are linked to tumor progression. Furthermore, failure in either activating a DNA damage checkpoint or repairing programmed meiotic double-strand breaks (DSBs) can impair chromosome segregation. Therefore, understanding the molecular basis for DNA damage response (DDR) and DSB repair (DSBR) within the germline is highly important. Here we define ZTF-8, a previously uncharacterized protein conserved from worms to humans, as a novel factor involved in the repair of both mitotic and meiotic DSBs as well as in meiotic DNA damage checkpoint activation in the C. elegans germline. ztf-8 mutants exhibit specific sensitivity to γ-irradiation and hydroxyurea, mitotic nuclear arrest at S-phase accompanied by activation of the ATL-1 and CHK-1 DNA damage checkpoint kinases, as well as accumulation of both mitotic and meiotic recombination intermediates, indicating that ZTF-8 functions in DSBR. However, impaired meiotic DSBR progression partially fails to trigger the CEP-1/p53-dependent DNA damage checkpoint in late pachytene, also supporting a role for ZTF-8 in meiotic DDR. ZTF-8 partially co-localizes with the 9-1-1 DDR complex and interacts with MRT-2/Rad1, a component of this complex. The human RHINO protein rescues the phenotypes observed in ztf-8 mutants, suggesting functional conservation across species. We propose that ZTF-8 is involved in promoting repair at stalled replication forks and meiotic DSBs by transducing DNA damage checkpoint signaling via the 9-1-1 pathway. Our findings define a conserved function for ZTF-8/RHINO in promoting genomic stability in the germline.
authors.affiliation: Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Hyun-Min
authors.initials: HM
authors.lastname: Kim
authors.affiliation: Department of Genetics, Harvard Medical School, Boston, Massachusetts, United States of America.
authors.forename: Monica P
authors.initials: MP
authors.lastname: Colaiácovo
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D064007:Ataxia Telangiectasia Mutated Proteins / Q000235:genetics / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism / Q000528:radiation effects; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D000071877:Checkpoint Kinase 1; D020090:Chromosome Segregation; D017124:Conserved Sequence; D053903:DNA Breaks, Double-Stranded / Q000187:drug effects / Q000528:radiation effects; D004249:DNA Damage; D004260:DNA Repair / Q000502:physiology; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005720:Gamma Rays / Q000009:adverse effects; D005854:Germ Cells / Q000187:drug effects / Q000502:physiology / Q000528:radiation effects; D008297:Male; D046912:Multiprotein Complexes / Q000378:metabolism; D009154:Mutation; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism
chemical_list: C438244:CEP-1 protein, C elegans; D029742:Caenorhabditis elegans Proteins; D004268:DNA-Binding Proteins; C403443:MRT-2 protein, C elegans; D046912:Multiprotein Complexes; D016159:Tumor Suppressor Protein p53; C000607008:ZTF-8 protein, C elegans; C576885:Atl-1 protein, C elegans; D011494:Protein Kinases; D064007:Ataxia Telangiectasia Mutated Proteins; D000071877:Checkpoint Kinase 1; C000605876:chk-1 protein, C elegans