Replication across damaged DNA templates is accompanied by transient formation of sister chromatid junctions (SCJs). Cells lacking Esc2, an adaptor protein containing no known enzymatic domains, are defective in the metabolism of these SCJs. However, how Esc2 is involved in the metabolism of SCJs remains elusive. Here we show interaction between Esc2 and a structure-specific endonuclease Mus81-Mms4 (the Mus81 complex), their involvement in the metabolism of SCJs, and the effects Esc2 has on the enzymatic activity of the Mus81 complex. We found that Esc2 specifically interacts with the Mus81 complex via its SUMO-like domains, stimulates enzymatic activity of the Mus81 complex in vitro, and is involved in the Mus81 complex-dependent resolution of SCJs in vivo Collectively, our data point to the possibility that the involvement of Esc2 in the metabolism of SCJs is, in part, via modulation of the activity of the Mus81 complex.
- MeSH
- chromatidy chemie metabolismus MeSH
- DNA fungální genetika metabolismus MeSH
- DNA vazebné proteiny chemie genetika metabolismus MeSH
- endonukleasy chemie genetika metabolismus MeSH
- Escherichia coli genetika metabolismus MeSH
- jaderné proteiny chemie genetika metabolismus MeSH
- klonování DNA MeSH
- křížová struktura DNA chemie metabolismus MeSH
- malé modifikační proteiny související s ubikvitinem chemie genetika metabolismus MeSH
- nestabilita genomu MeSH
- poškození DNA MeSH
- proteinové domény MeSH
- regulace genové exprese u hub * MeSH
- rekombinantní proteiny chemie genetika metabolismus MeSH
- replikace DNA MeSH
- Saccharomyces cerevisiae - proteiny chemie genetika metabolismus MeSH
- Saccharomyces cerevisiae genetika metabolismus MeSH
- vazba proteinů MeSH
- Publikační typ
- časopisecké články MeSH
Topoisomerase IIβ-binding protein 1 (TOPBP1) participates in DNA replication and DNA damage response; however, its role in DNA repair and relevance for human cancer remain unclear. Here, through an unbiased small interfering RNA screen, we identified and validated TOPBP1 as a novel determinant whose loss sensitized human cells to olaparib, an inhibitor of poly(ADP-ribose) polymerase. We show that TOPBP1 acts in homologous recombination (HR) repair, impacts olaparib response, and exhibits aberrant patterns in subsets of human ovarian carcinomas. TOPBP1 depletion abrogated RAD51 loading to chromatin and formation of RAD51 foci, but without affecting the upstream HR steps of DNA end resection and RPA loading. Furthermore, TOPBP1 BRCT domains 7/8 are essential for RAD51 foci formation. Mechanistically, TOPBP1 physically binds PLK1 and promotes PLK1 kinase-mediated phosphorylation of RAD51 at serine 14, a modification required for RAD51 recruitment to chromatin. Overall, our results provide mechanistic insights into TOPBP1's role in HR, with potential clinical implications for cancer treatment.
- MeSH
- časové faktory MeSH
- chromatin metabolismus MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- fosforylace MeSH
- ftalaziny farmakologie MeSH
- HEK293 buňky MeSH
- HeLa buňky MeSH
- homologní rekombinace * MeSH
- interakční proteinové domény a motivy MeSH
- jaderné proteiny genetika metabolismus MeSH
- lidé MeSH
- nádory vaječníků farmakoterapie enzymologie genetika patologie MeSH
- PARP inhibitory farmakologie MeSH
- piperaziny farmakologie MeSH
- protein-serin-threoninkinasy metabolismus MeSH
- proteiny buněčného cyklu metabolismus MeSH
- protoonkogenní proteiny metabolismus MeSH
- rekombinasa Rad51 genetika metabolismus MeSH
- restrukturace chromatinu * MeSH
- RNA interference MeSH
- signální transdukce účinky léků MeSH
- transfekce MeSH
- transportní proteiny genetika metabolismus MeSH
- vazba proteinů MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
