RNA methylation, especially 6-methyladenosine (m6A)-modified RNAs, plays a specific role in DNA damage response (DDR). Here, we also observe that RNA modified at 8-methyladenosine (m8A) is recruited to UVA-damaged chromatin immediately after microirradiation. Interestingly, the level of m8A RNA at genomic lesions was reduced after inhibition of histone deacetylases and DNA methyltransferases. It appears in later phases of DNA damage response, accompanied by active DNA demethylation. Also, PARP inhibitor (PARPi), Olaparib, prevented adenosine methylation at microirradiated chromatin. PARPi abrogated not only m6A and m8A RNA positivity at genomic lesions, but also XRCC1, the factor of base excision repair (BER), did not recognize lesions in DNA. To this effect, Olaparib enhanced the genome-wide level of γH2AX. This histone modification interacted with m8A RNAs to a similar extent as m8A RNAs with DNA. Pronounced interaction properties we did not observe for m6A RNAs and DNA; however, m6A RNA interacted with XRCC1 with the highest efficiency, especially in microirradiated cells. Together, we show that the recruitment of m6A RNA and m8A RNA to DNA lesions is PARP dependent. We suggest that modified RNAs likely play a role in the BER mechanism accompanied by active DNA demethylation. In this process, γH2AX stabilizes m6A/m8A-positive RNA-DNA hybrid loops via its interaction with m8A RNAs. R-loops could represent basic three-stranded structures recognized by PARP-dependent non-canonical m6A/m8A-mediated DNA repair pathway.
The DNA damage response is mediated by both DNA repair proteins and epigenetic markers. Here, we observe that N6-methyladenosine (m6A), a mark of the epitranscriptome, was common in RNAs accumulated at UV-damaged chromatin; however, inhibitors of RNA polymerases I and II did not affect the m6A RNA level at the irradiated genomic regions. After genome injury, m6A RNAs either diffused to the damaged chromatin or appeared at the lesions enzymatically. DNA damage did not change the levels of METTL3 and METTL14 methyltransferases. In a subset of irradiated cells, only the METTL16 enzyme, responsible for m6A in non-coding RNAs as well as for splicing regulation, was recruited to microirradiated sites. Importantly, the levels of the studied splicing factors were not changed by UVA light. Overall, if the appearance of m6A RNAs at DNA lesions is regulated enzymatically, this process must be mediated via the coregulatory function of METTL-like enzymes. This event is additionally accompanied by radiation-induced depletion of 2,2,7-methylguanosine (m3G/TMG) in RNA. Moreover, UV-irradiation also decreases the global cellular level of N1-methyladenosine (m1A) in RNAs. Based on these results, we prefer a model in which m6A RNAs rapidly respond to radiation-induced stress and diffuse to the damaged sites. The level of both (m1A) RNAs and m3G/TMG in RNAs is reduced as a consequence of DNA damage, recognized by the nucleotide excision repair mechanism.
- MeSH
- adenosin analogy a deriváty metabolismus MeSH
- chromatin metabolismus MeSH
- demetylace DNA účinky záření MeSH
- fyziologický stres účinky záření MeSH
- guanosin analogy a deriváty metabolismus MeSH
- metylace DNA genetika účinky záření MeSH
- metylace účinky záření MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nekódující RNA metabolismus MeSH
- nestabilita genomu účinky záření MeSH
- poškození DNA MeSH
- RNA metabolismus MeSH
- ultrafialové záření * MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- demetylace DNA MeSH
- embryonální a fetální vývoj genetika MeSH
- enzymy metabolismus MeSH
- epigenomika * MeSH
- exprese genu genetika MeSH
- genom genetika MeSH
- histony genetika MeSH
- kyselina askorbová * genetika metabolismus MeSH
- lidé MeSH
- nádory metabolismus MeSH
- nedostatek vitaminu C metabolismus MeSH
- stárnutí metabolismus MeSH
- vývoj dítěte MeSH
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- lidé MeSH
