Ubiquitinated-PCNA protects replication forks from DNA2-mediated degradation by regulating Okazaki fragment maturation and chromatin assembly
| Autor: | Claudia M. Nicolae, Wendy Leung, Tanay Thakar, Binghui Shen, Kristen E. Clements, George Lucian Moldovan, Anja Katrin Bielinsky |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
DNA Replication
0301 basic medicine Genome instability DNA Repair DNA polymerase Science Fluorescent Antibody Technique General Physics and Astronomy Article Genomic Instability General Biochemistry Genetics and Molecular Biology 03 medical and health sciences chemistry.chemical_compound 0302 clinical medicine Ubiquitin Cell Line Tumor Proliferating Cell Nuclear Antigen Humans Nucleosome lcsh:Science Multidisciplinary biology Okazaki fragments DNA damage and repair HEK 293 cells Ubiquitination Stalled forks DNA General Chemistry Chromatin Assembly and Disassembly Cell biology Proliferating cell nuclear antigen HEK293 Cells 030104 developmental biology chemistry biology.protein lcsh:Q Comet Assay 030217 neurology & neurosurgery DNA Damage HeLa Cells Protein Binding |
| Zdroj: | Nature Communications, Vol 11, Iss 1, Pp 1-14 (2020) Nature Communications |
| ISSN: | 2041-1723 |
| DOI: | 10.1038/s41467-020-16096-w |
| Popis: | Upon genotoxic stress, PCNA ubiquitination allows for replication of damaged DNA by recruiting lesion-bypass DNA polymerases. However, PCNA is also ubiquitinated during normal S-phase progression. By employing 293T and RPE1 cells deficient in PCNA ubiquitination, generated through CRISPR/Cas9 gene editing, here, we show that this modification promotes cellular proliferation and suppression of genomic instability under normal growth conditions. Loss of PCNA-ubiquitination results in DNA2-dependent but MRE11-independent nucleolytic degradation of nascent DNA at stalled replication forks. This degradation is linked to defective gap-filling in the wake of the replication fork and incomplete Okazaki fragment maturation, which interferes with efficient PCNA unloading by ATAD5 and subsequent nucleosome deposition by CAF-1. Moreover, concomitant loss of PCNA-ubiquitination and the BRCA pathway results in increased nascent DNA degradation and PARP inhibitor sensitivity. In conclusion, we show that by ensuring efficient Okazaki fragment maturation, PCNA-ubiquitination protects fork integrity and promotes the resistance of BRCA-deficient cells to PARP-inhibitors. PCNA is essential for DNA replication and cellular proliferation. Here, the authors reveal that PCNA ubiquitination protects stalled replication forks from DNA2-mediated degradation via regulation of Okazaki fragment maturation and chromatin assembly. |
| Databáze: | OpenAIRE |
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