Poly(ADP-ribosyl)ation is a reversible post-translational modification synthetized by ADP-ribose transferases and removed by poly(ADP-ribose) glycohydrolase (PARG), which plays important roles in DNA damage repair. While well-studied in somatic tissues, much less is known about poly(ADP-ribosyl)ation in the germline, where DNA double-strand breaks are introduced by a regulated program and repaired by crossover recombination to establish a tether between homologous chromosomes. The interaction between the parental chromosomes is facilitated by meiotic specific adaptation of the chromosome axes and cohesins, and reinforced by the synaptonemal complex. Here, we uncover an unexpected role for PARG in coordinating the induction of meiotic DNA breaks and their homologous recombination-mediated repair in Caenorhabditis elegans. PARG-1/PARG interacts with both axial and central elements of the synaptonemal complex, REC-8/Rec8 and the MRN/X complex. PARG-1 shapes the recombination landscape and reinforces the tightly regulated control of crossover numbers without requiring its catalytic activity. We unravel roles in regulating meiosis, beyond its enzymatic activity in poly(ADP-ribose) catabolism.
- MeSH
- buněčné jádro metabolismus MeSH
- Caenorhabditis elegans genetika metabolismus MeSH
- DNA metabolismus MeSH
- dvouřetězcové zlomy DNA * MeSH
- glykosidhydrolasy genetika metabolismus MeSH
- jaderné proteiny genetika metabolismus MeSH
- oprava DNA fyziologie MeSH
- poly-ADP-ribosylace MeSH
- polyadenosindifosfátribosa metabolismus MeSH
- posttranslační úpravy proteinů MeSH
- proteiny Caenorhabditis elegans genetika metabolismus MeSH
- zárodečné buňky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Poly(ADP-ribose) is synthesized by PARP enzymes during the repair of stochastic DNA breaks. Surprisingly, however, we show that most if not all endogenous poly(ADP-ribose) is detected in normal S phase cells at sites of DNA replication. This S phase poly(ADP-ribose) does not result from damaged or misincorporated nucleotides or from DNA replication stress. Rather, perturbation of the DNA replication proteins LIG1 or FEN1 increases S phase poly(ADP-ribose) more than 10-fold, implicating unligated Okazaki fragments as the source of S phase PARP activity. Indeed, S phase PARP activity is ablated by suppressing Okazaki fragment formation with emetine, a DNA replication inhibitor that selectively inhibits lagging strand synthesis. Importantly, PARP activation during DNA replication recruits the single-strand break repair protein XRCC1, and human cells lacking PARP activity and/or XRCC1 are hypersensitive to FEN1 perturbation. Collectively, our data indicate that PARP1 is a sensor of unligated Okazaki fragments during DNA replication and facilitates their repair.
- MeSH
- "flap" endonukleasy metabolismus MeSH
- buněčné linie MeSH
- DNA vazebné proteiny metabolismus MeSH
- DNA-ligasa ATP metabolismus MeSH
- DNA genetika metabolismus MeSH
- lidé MeSH
- oprava DNA MeSH
- poly-ADP-ribóza-polymeráza 1 metabolismus MeSH
- poly(ADP-ribosa)-polymerasy genetika metabolismus MeSH
- polyadenosindifosfátribosa metabolismus MeSH
- poškození DNA MeSH
- protein XRCC1 metabolismus MeSH
- replikace DNA fyziologie MeSH
- S fáze fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH