Most cited article - PubMed ID 15671549
PML, a multifunctional protein, is crucial for forming PML-nuclear bodies involved in stress responses. Under specific conditions, PML associates with nucleolar caps formed after RNA polymerase I (RNAPI) inhibition, leading to PML-nucleolar associations (PNAs). This study investigates PNAs-inducing stimuli by exposing cells to various genotoxic stresses. We found that the most potent inducers of PNAs introduced topological stress and inhibited RNAPI. Doxorubicin, the most effective compound, induced double-strand breaks (DSBs) in the rDNA locus. PNAs co-localized with damaged rDNA, segregating it from active nucleoli. Cleaving the rDNA locus with I-PpoI confirmed rDNA damage as a genuine stimulus for PNAs. Inhibition of ATM, ATR kinases, and RAD51 reduced I-PpoI-induced PNAs, highlighting the importance of ATM/ATR-dependent nucleolar cap formation and homologous recombination (HR) in their triggering. I-PpoI-induced PNAs co-localized with rDNA DSBs positive for RPA32-pS33 but deficient in RAD51, indicating resected DNA unable to complete HR repair. Our findings suggest that PNAs form in response to persistent rDNA damage within the nucleolar cap, highlighting the interplay between PML/PNAs and rDNA alterations due to topological stress, RNAPI inhibition, and rDNA DSBs destined for HR. Cells with persistent PNAs undergo senescence, suggesting PNAs help avoid rDNA instability, with implications for tumorigenesis and aging.
- Keywords
- PML, aberrant DNA topology, cancer biology, cell biology, cellular senescence, genome maintenance, human, persistent rDNA damage,
- MeSH
- Cell Nucleolus * metabolism MeSH
- DNA Breaks, Double-Stranded MeSH
- Humans MeSH
- DNA Damage MeSH
- Promyelocytic Leukemia Protein * metabolism genetics MeSH
- DNA, Ribosomal * genetics metabolism MeSH
- RNA Polymerase I metabolism genetics MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Names of Substances
- PML protein, human MeSH Browser
- Promyelocytic Leukemia Protein * MeSH
- DNA, Ribosomal * MeSH
- RNA Polymerase I MeSH
