BACKGROUND: Polymorphisms in thiopurine methyltransferase (TPMT) are a predominant cause of azathioprine-induced leucopenia in Western countries. The exact role of these polymorphisms in the Indian population with dermatological disorders is uncertain. OBJECTIVES: To evaluate the frequency of genetic polymorphism of TPMT and its impact on the safety of azathioprine in dermatological disorders. METHODS: We included consecutive patients on azathioprine who were initiated for dermatological disorders from South India. Three TPMT polymorphisms (c.238G>C, c.460G>A and c.719A>G) were assessed. The proportions of adverse events to azathioprine, especially myelosuppression, were compared between those with the wildtype genotype and those with TPMT polymorphisms. RESULTS: Of the 123 patients (61 male and 62 female, mean age 46 years), 65% had an autoimmune blistering disorder. Adverse events to azathioprine were noted in 25 (20.3%), of whom 16 (13.0%) had myelosuppression and 4 (3.2%) each had hepatotoxicity and gastrointestinal intolerance. TPMT polymorphisms were detected in 13 (10.6%), of whom 5 had experienced adverse events. The polymorphisms could explain 25% (4 of 16) of the cases of leucopenia. The odds of developing leucopenia in patients with TPMT polymorphism were not significant (odds ratio 3.63, 95% confidence interval 0.96-13.6; P = 0.06). CONCLUSIONS: The tested TPMT polymorphisms could not predict the adverse events of azathioprine, particularly the haematological toxicity, in dermatological use among the South Indian population.
- MeSH
- azathioprin * škodlivé účinky terapeutické užití MeSH
- dospělí MeSH
- genotyp MeSH
- imunosupresiva * škodlivé účinky terapeutické užití MeSH
- klinická relevance MeSH
- kožní nemoci * farmakoterapie genetika MeSH
- leukopenie chemicky indukované genetika MeSH
- lidé středního věku MeSH
- lidé MeSH
- methyltransferasy * genetika MeSH
- mladiství MeSH
- mladý dospělý MeSH
- polymorfismus genetický MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Indie MeSH
OBJECTIVES: To analyse characteristics of Clostridioides difficile PCR ribotype 176 clinical isolates from Poland, the Czech Republic and Slovakia with regard to the differences in its epidemiology. METHODS: Antimicrobial susceptibility testing and whole genome sequencing were performed on a selected group of 22 clonally related isolates as determined by multilocus variable-number tandem repeat analysis (n = 509). Heterologous expression and functional analysis of the newly identified methyltransferase were performed. RESULTS: Core genome multilocus sequence typing found 10-37 allele differences. All isolates were resistant to fluoroquinolones (gyrA_p. T82I), aminoglycosides with aac(6')-Ie-aph(2'')-Ia in six isolates. Erythromycin resistance was detected in 21/22 isolates and 15 were also resistant to clindamycin with ermB gene. Fourteen isolates were resistant to rifampicin with rpoB_p. R505K or p. R505K/H502N, and five to imipenem with pbp1_p. P491L and pbp3_p. N537K. PnimBG together with nimB_p. L155I were detected in all isolates but only five were resistant to metronidazole on chocolate agar. The cfrE, vanZ1 and cat-like genes were not associated with linezolid, teicoplanin and chloramphenicol resistance, respectively. The genome comparison identified six transposons carrying antimicrobial resistance genes. The ermB gene was carried by new Tn7808, Tn6189 and Tn6218-like. The aac(6')-Ie-aph(2'')-Ia were carried by Tn6218-like and new Tn7806 together with cfrE gene. New Tn7807 carried a cat-like gene. Tn6110 and new Tn7806 contained an RlmN-type 23S rRNA methyltransferase, designated MrmA, associated with high-level macrolide resistance in isolates without ermB gene. CONCLUSIONS: Multidrug-resistant C. difficile PCR ribotype 176 isolates carry already described and unique transposons. A novel mechanism for erythromycin resistance in C. difficile was identified.
- MeSH
- antibakteriální látky * farmakologie MeSH
- bakteriální léková rezistence * MeSH
- bakteriální proteiny genetika MeSH
- Clostridioides difficile * genetika účinky léků izolace a purifikace klasifikace MeSH
- genomové ostrovy * MeSH
- klostridiové infekce * mikrobiologie epidemiologie MeSH
- lidé MeSH
- methyltransferasy genetika MeSH
- mikrobiální testy citlivosti MeSH
- mnohočetná bakteriální léková rezistence * genetika MeSH
- multilokusová sekvenční typizace MeSH
- ribotypizace MeSH
- sekvenování celého genomu MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Česká republika MeSH
- Polsko MeSH
Nonalcoholic fatty liver disease (NAFLD) is characterized by elevated hepatic lipids caused by nonalcoholic factors, where histone lactylation is lately discovered as a modification driving disease progression. This research aimed to explore the role of histone 3 lysine 18 lactylation (H3K18lac) in NAFLD progression using a high-fat diet (HFD)-treated mouse model and free fatty acids (FFA)-treated L-02 cell lines. Lipids accumulation was screened via Oil Red O staining, real-time quantitative polymerase chain reaction (RT-qPCR), western blotting, and commercially available kits. Similarly, molecular mechanism was analyzed using immunoprecipitation (IP), dual-luciferase reporter assay, and RNA decay assay. Results indicated that FFA upregulated lactate dehydrogenase A (LDHA) and H3K18lac levels in L-02 cells. Besides, LDHA-mediated H3K18lac was enriched on the proximal promoter of methyltransferase 3 (METTL3), translating into an increased expression. Moreover, METTL3 or LDHA knockdown relieved lipid accumulation, decreased total cholesterol (TC) and triglyceride (TG) levels, and downregulated lipogenesis-related proteins in FFA-treated L-02 cell lines, in addition to enhancing the m6A and mRNA levels of stearoyl-coenzyme A desaturase 1 (SCD1). The m6A modification of SCD1 was recognized by YTH N6-methyladenosine RNA binding protein F1 (YTHDF1), resulting in enhanced mRNA stability. LDHA was found to be highly expressed in HFD-treated mice, where knocking down LDHA attenuated HFD-induced hepatic steatosis. These findings demonstrated that LDHA-induced H3K18lac promoted NAFLD progression, where LDHA-induced H3K18lac in METTL3 promoter elevated METTL3 expression, thereby promoting m6A methylation and stabilizing SCD1 via a YTHDF1-dependent manner. Keywords: Nonalcoholic fatty liver disease, LDHA, METTL3, YTHDF1, Histone lactylation.
- MeSH
- adenosin * metabolismus analogy a deriváty MeSH
- dieta s vysokým obsahem tuků škodlivé účinky MeSH
- histony * metabolismus MeSH
- L-laktátdehydrogenasa metabolismus MeSH
- lidé MeSH
- methyltransferasy * metabolismus genetika MeSH
- myši inbrední C57BL * MeSH
- myši MeSH
- nealkoholová steatóza jater * metabolismus patologie MeSH
- progrese nemoci * MeSH
- proteiny vázající RNA * metabolismus genetika MeSH
- stearyl-CoA-desaturasa * metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Methylation of histone H3 at lysine 36 (H3K36me3) marks active chromatin. The mark is interpreted by epigenetic readers that assist transcription and safeguard the integrity of the chromatin fiber. The chromodomain protein MSL3 binds H3K36me3 to target X-chromosomal genes in male Drosophila for dosage compensation. The PWWP-domain protein JASPer recruits the JIL1 kinase to active chromatin on all chromosomes. Unexpectedly, depletion of K36me3 had variable, locus-specific effects on the interactions of those readers. This observation motivated a systematic and comprehensive study of K36 methylation in a defined cellular model. Contrasting prevailing models, we found that K36me1, K36me2 and K36me3 each contribute to distinct chromatin states. A gene-centric view of the changing K36 methylation landscape upon depletion of the three methyltransferases Set2, NSD and Ash1 revealed local, context-specific methylation signatures. Set2 catalyzes K36me3 predominantly at transcriptionally active euchromatin. NSD places K36me2/3 at defined loci within pericentric heterochromatin and on weakly transcribed euchromatic genes. Ash1 deposits K36me1 at regions with enhancer signatures. The genome-wide mapping of MSL3 and JASPer suggested that they bind K36me2 in addition to K36me3, which was confirmed by direct affinity measurement. This dual specificity attracts the readers to a broader range of chromosomal locations and increases the robustness of their actions.
- MeSH
- chromatin * metabolismus MeSH
- DNA vazebné proteiny metabolismus genetika MeSH
- Drosophila melanogaster genetika metabolismus MeSH
- heterochromatin metabolismus genetika MeSH
- histonlysin-N-methyltransferasa * metabolismus genetika MeSH
- histony * metabolismus MeSH
- lysin metabolismus MeSH
- methyltransferasy metabolismus genetika MeSH
- metylace MeSH
- protein-serin-threoninkinasy MeSH
- proteiny Drosophily * metabolismus genetika MeSH
- transkripční faktory metabolismus genetika MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Frequent truncation mutations of the histone lysine N-methyltransferase KMT2C have been detected by whole exome sequencing studies in various cancers, including malignancies of the prostate. However, the biological consequences of these alterations in prostate cancer have not yet been elucidated. METHODS: To investigate the functional effects of these mutations, we deleted the C-terminal catalytic core motif of Kmt2c specifically in mouse prostate epithelium. We analysed the effect of Kmt2c SET domain deletion in a Pten-deficient PCa mouse model in vivo and of truncation mutations of KMT2C in a large number of prostate cancer patients. RESULTS: We show here for the first time that impaired KMT2C methyltransferase activity drives proliferation and PIN formation and, when combined with loss of the tumour suppressor PTEN, triggers loss of senescence, metastatic dissemination and dramatically reduces life expectancy. In Kmt2c-mutated tumours we show enrichment of proliferative MYC gene signatures and loss of expression of the cell cycle repressor p16INK4A. In addition, we observe a striking reduction in disease-free survival of patients with KMT2C-mutated prostate cancer. CONCLUSIONS: We identified truncating events of KMT2C as drivers of proliferation and PIN formation. Loss of PTEN and KMT2C in prostate cancer results in loss of senescence, metastatic dissemination and reduced life expectancy. Our data demonstrate the prognostic significance of KMT2C mutation status in prostate cancer patients. Inhibition of the MYC signalling axis may be a viable treatment option for patients with KMT2C truncations and therefore poor prognosis.
- MeSH
- DNA vazebné proteiny fyziologie MeSH
- inhibitor p16 cyklin-dependentní kinasy genetika metabolismus MeSH
- lidé MeSH
- methyltransferasy * genetika MeSH
- mutace MeSH
- myši MeSH
- nádory prostaty * metabolismus MeSH
- sekvenování exomu MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
N6-methyladenosine (m6A) and N6,2'-O-dimethyladenosine (m6Am) are two abundant modifications found in mRNAs and ncRNAs that can regulate multiple aspects of RNA biology. They function mainly by regulating interactions with specific RNA-binding proteins. Both modifications are linked to development, disease and stress response. To date, three methyltransferases and two demethylases have been identified that modify adenosines in mammalian mRNAs. Here, we present a comprehensive analysis of the interactomes of these enzymes. PCIF1 protein network comprises mostly factors involved in nascent RNA synthesis by RNA polymerase II, whereas ALKBH5 is closely linked with most aspects of pre-mRNA processing and mRNA export to the cytoplasm. METTL16 resides in subcellular compartments co-inhabited by several other RNA modifiers and processing factors. FTO interactome positions this demethylase at a crossroad between RNA transcription, RNA processing and DNA replication and repair. Altogether, these enzymes share limited spatial interactomes, pointing to specific molecular mechanisms of their regulation.
- MeSH
- adaptorové proteiny signální transdukční genetika metabolismus MeSH
- adenosin analogy a deriváty metabolismus MeSH
- alfa-ketoglutarát-dependentní dioxygenasa, AlkB homolog 5 genetika metabolismus MeSH
- anotace sekvence MeSH
- gen pro FTO genetika metabolismus MeSH
- genetická transkripce MeSH
- genová ontologie MeSH
- HEK293 buňky MeSH
- jaderné proteiny genetika metabolismus MeSH
- lidé MeSH
- mapování interakce mezi proteiny MeSH
- messenger RNA genetika metabolismus MeSH
- methyltransferasy genetika metabolismus MeSH
- N-demethylasy genetika metabolismus MeSH
- nekódující RNA genetika metabolismus MeSH
- oprava DNA MeSH
- protein - isoformy genetika metabolismus MeSH
- replikace DNA MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The ongoing COVID-19 pandemic exemplifies the general need to better understand viral infections. The positive single-strand RNA genome of its causative agent, the SARS coronavirus 2 (SARS-CoV-2), encodes all viral enzymes. In this work, we focused on one particular methyltransferase (MTase), nsp16, which, in complex with nsp10, is capable of methylating the first nucleotide of a capped RNA strand at the 2'-O position. This process is part of a viral capping system and is crucial for viral evasion of the innate immune reaction. In light of recently discovered non-canonical RNA caps, we tested various dinucleoside polyphosphate-capped RNAs as substrates for nsp10-nsp16 MTase. We developed an LC-MS-based method and discovered four types of capped RNA (m7Gp3A(G)- and Gp3A(G)-RNA) that are substrates of the nsp10-nsp16 MTase. Our technique is an alternative to the classical isotope labelling approach for the measurement of 2'-O-MTase activity. Further, we determined the IC50 value of sinefungin to illustrate the use of our approach for inhibitor screening. In the future, this approach may be an alternative technique to the radioactive labelling method for screening inhibitors of any type of 2'-O-MTase.
- MeSH
- chromatografie kapalinová MeSH
- COVID-19 virologie MeSH
- hmotnostní spektrometrie MeSH
- lidé MeSH
- methyltransferasy genetika metabolismus MeSH
- metylace MeSH
- regulace exprese virových genů MeSH
- RNA čepičky MeSH
- RNA virová genetika MeSH
- SARS-CoV-2 enzymologie genetika MeSH
- substrátová specifita MeSH
- virové nestrukturální proteiny genetika metabolismus MeSH
- virové regulační a přídatné proteiny genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of the coronavirus disease-19 pandemic. One of the key components of the coronavirus replication complex are the RNA methyltransferases (MTases), RNA-modifying enzymes crucial for RNA cap formation. Recently, the structure of the 2'-O MTase has become available; however, its biological characterization within the infected cells remains largely elusive. Here, we report a novel monoclonal antibody directed against the SARS-CoV-2 non-structural protein nsp10, a subunit of both the 2'-O RNA and N7 MTase protein complexes. Using this antibody, we investigated the subcellular localization of the SARS-CoV-2 MTases in cells infected with the SARS-CoV-2.
- MeSH
- COVID-19 virologie MeSH
- lidé MeSH
- methyltransferasy analýza genetika metabolismus MeSH
- monoklonální protilátky analýza MeSH
- RNA čepičky genetika metabolismus MeSH
- RNA virová genetika metabolismus MeSH
- SARS-CoV-2 chemie enzymologie genetika MeSH
- transport proteinů MeSH
- virové nestrukturální proteiny analýza genetika metabolismus MeSH
- virové regulační a přídatné proteiny analýza genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The OC43 coronavirus is a human pathogen that usually causes only the common cold. One of its key enzymes, similar to other coronaviruses, is the 2'-O-RNA methyltransferase (MTase), which is essential for viral RNA stability and expression. Here, we report the crystal structure of the 2'-O-RNA MTase in a complex with the pan-methyltransferase inhibitor sinefungin solved at 2.2-Å resolution. The structure reveals an overall fold consistent with the fold observed in other coronaviral MTases. The major differences are in the conformation of the C terminus of the nsp16 subunit and an additional helix in the N terminus of the nsp10 subunits. The structural analysis also revealed very high conservation of the S-adenosyl methionine (SAM) binding pocket, suggesting that the SAM pocket is a suitable spot for the design of antivirals effective against all human coronaviruses. IMPORTANCE Some coronaviruses are dangerous pathogens, while some cause only common colds. The reasons are not understood, although the spike proteins probably play an important role. However, to understand the coronaviral biology in sufficient detail, we need to compare the key enzymes from different coronaviruses. We solved the crystal structure of 2'-O-RNA methyltransferase of the OC43 coronavirus, a virus that usually causes mild colds. The structure revealed some differences in the overall fold but also revealed that the SAM binding site is conserved, suggesting that development of antivirals against multiple coronaviruses is feasible.
In this study, we have focused on the structure-based design of the inhibitors of one of the two SARS-CoV-2 methyltransferases (MTases), nsp14. This MTase catalyzes the transfer of the methyl group from S-adenosyl-l-methionine (SAM) to cap the guanosine triphosphate moiety of the newly synthesized viral RNA, yielding the methylated capped RNA and S-adenosyl-l-homocysteine (SAH). As the crystal structure of SARS-CoV-2 nsp14 is unknown, we have taken advantage of its high homology to SARS-CoV nsp14 and prepared its homology model, which has allowed us to identify novel SAH derivatives modified at the adenine nucleobase as inhibitors of this important viral target. We have synthesized and tested the designed compounds in vitro and shown that these derivatives exert unprecedented inhibitory activity against this crucial enzyme. The docking studies nicely explain the contribution of an aromatic part attached by a linker to the position 7 of the 7-deaza analogues of SAH.
- MeSH
- COVID-19 * MeSH
- exoribonukleasy MeSH
- lidé MeSH
- ligandy MeSH
- methyltransferasy * genetika MeSH
- SARS-CoV-2 MeSH
- virové nestrukturální proteiny MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
