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
Establishment of the early genetic code likely required strategies to ensure translational accuracy and inevitably involved tRNA post-transcriptional modifications. One such modification, wybutosine/wyosine is crucial for translational fidelity in Archaea and Eukarya; yet it does not occur in Bacteria and has never been described in mitochondria. Here, we present genetic, molecular and mass spectromery data demonstrating the first example of wyosine in mitochondria, a situation thus far unique to kinetoplastids. We also show that these modifications are important for mitochondrial function, underscoring their biological significance. This work focuses on TyW1, the enzyme required for the most critical step of wyosine biosynthesis. Based on molecular phylogeny, we suggest that the kinetoplastids pathways evolved via gene duplication and acquisition of an FMN-binding domain now prevalent in TyW1 of most eukaryotes. These findings are discussed in the context of the extensive U-insertion RNA editing in trypanosome mitochondria, which may have provided selective pressure for maintenance of mitochondrial wyosine in this lineage.
- MeSH
- guanosin analogy a deriváty biosyntéza chemie metabolismus MeSH
- mitochondrie enzymologie MeSH
- posttranskripční úpravy RNA MeSH
- protozoální proteiny genetika metabolismus MeSH
- RNA transferová chemie metabolismus MeSH
- Trypanosoma brucei brucei enzymologie genetika MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Aging is a complex process of organism decline in physiological functions. There is no clear theory explaining this phenomenon, but the most accepted one is the oxidative stress theory of aging. Biomarkers of oxidative stress, substances, which are formed during oxidative damage of phospholipids, proteins, and nucleic acids, are present in body fluids of diseased people as well as the healthy ones (in a physiological concentration). 8-iso prostaglandin F2α is the most prominent biomarker of phospholipid oxidative damage, o-tyrosine, 3-chlorotyrosine, and 3-nitrotyrosine are biomarkers of protein oxidative damage, and 8-hydroxy-2(')-deoxyguanosine and 8-hydroxyguanosine are biomarkers of oxidative damage of nucleic acids. It is thought that the concentration of biomarkers increases as the age of people increases. However, the concentration of biomarkers in body fluids is very low and, therefore, it is necessary to use a sensitive analytical method. A combination of HPLC and MS was chosen to determine biomarker concentration in three groups of healthy people of a different age (twenty, forty, and sixty years) in order to find a difference among the groups.
- MeSH
- biologické markery metabolismus MeSH
- dinoprost analogy a deriváty metabolismus MeSH
- guanosin analogy a deriváty metabolismus MeSH
- lidé MeSH
- oxidační stres * MeSH
- poškození DNA MeSH
- proteiny chemie metabolismus MeSH
- stárnutí * MeSH
- tyrosin analogy a deriváty metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- MeSH
- biomedicínský výzkum MeSH
- časové faktory MeSH
- diagnostické techniky a postupy MeSH
- diferenciální diagnóza MeSH
- dnavá artritida * etiologie metabolismus MeSH
- guanosin * metabolismus MeSH
- kyselina močová krev metabolismus MeSH
- lidé MeSH
- metabolismus * MeSH
- puriny krev metabolismus škodlivé účinky MeSH
- statistika jako téma MeSH
- Check Tag
- lidé MeSH
