RNA methyltransferase Dotaz Zobrazit nápovědu
Mpox is a zoonotic disease caused by the mpox virus (MPXV), which has gained attention due to its rapid and widespread transmission, with reports from more than 100 countries. The virus belongs to the Orthopoxvirus genus, which also includes variola virus and vaccinia virus. In poxviruses, the RNA cap is crucial for the translation and stability of viral mRNAs and also for immune evasion. This study presents the crystal structure of the mpox 2'-O-methyltransfarase VP39 in complex with a short cap-0 RNA. The RNA substrate binds to the protein without causing any significant changes to its overall fold and is held in place by a combination of electrostatic interactions, π-π stacking and hydrogen bonding. The structure also explains the mpox VP39 preference for a guanine base at the first position; it reveals that guanine forms a hydrogen bond that an adenine would not be able to form.
- MeSH
- lidé MeSH
- methyltransferasy chemie MeSH
- metylace MeSH
- opičí neštovice * MeSH
- RNA čepičky * metabolismus MeSH
- vazebná místa MeSH
- virové proteiny genetika 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 cause of the COVID-19 pandemic. 2'-O-RNA methyltransferase (MTase) is one of the enzymes of this virus that is a potential target for antiviral therapy as it is crucial for RNA cap formation; an essential process for viral RNA stability. This MTase function is associated with the nsp16 protein, which requires a cofactor, nsp10, for its proper activity. Here we show the crystal structure of the nsp10-nsp16 complex bound to the pan-MTase inhibitor sinefungin in the active site. Our structural comparisons reveal low conservation of the MTase catalytic site between Zika and SARS-CoV-2 viruses, but high conservation of the MTase active site between SARS-CoV-2 and SARS-CoV viruses; these data suggest that the preparation of MTase inhibitors targeting several coronaviruses - but not flaviviruses - should be feasible. Together, our data add to important information for structure-based drug discovery.
- MeSH
- adenosin analogy a deriváty metabolismus farmakologie MeSH
- Betacoronavirus enzymologie MeSH
- chemické modely MeSH
- inhibitory enzymů metabolismus farmakologie MeSH
- katalytická doména MeSH
- koronavirové infekce virologie MeSH
- krystalografie rentgenová MeSH
- lidé MeSH
- methyltransferasy chemie metabolismus MeSH
- molekulární modely MeSH
- pandemie MeSH
- RNA čepičky MeSH
- RNA virová metabolismus MeSH
- stabilita RNA MeSH
- virová pneumonie virologie MeSH
- virové nestrukturální proteiny chemie metabolismus MeSH
- virové regulační a přídatné proteiny chemie 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.
Epigenetika se zabývá tím, jak zevní i vnitřní faktory ovlivňují funkci DNA daného organizmu, aniž by se přitom měnila její sekvence. Epigenetické vlivy jsou významné jak v buňkách stávajících, tak dceřiných, a to v rámci jedince i mezigeneračního přenosu získaných znaků. Za nejvýznamnější epigenetické mechanizmy bývají považovány acetylace histonů a metylace DNA, k nim však přistupuje řada dalších molekulárních procesů. Vedle epigenetiky je dalším odvětvím molekulární biologie výzkum nekódující RNA, který se začíná uplatňovat také ve studiu psychických poruch. Nekódující RNA, vznikající především z tzv. nesmyslné DNA, ovlivňuje genovou expresi. I Epigenetické výzkumy doposud byly prováděny jen na tkáních in vitro, pokusných zvířatech a zemřelých nemocných. Chybí epigenetické klinické studie. Do budoucna se jako nadějná jeví epigenetická terapie kognitivních poruch, schizofrenie a poruch nálady. Přitom je možno využívat jak léků stávajících (např. valproát, klozapin, sulpirid, escitalopram, lithium), tak látek nově syntetizovaných. Problémem je, že epigenetické účinky uvedených látek nejsou topicky, tkáňově, enzymaticky či genově specifické. To může vést k závažným nežádoucím účinkům. V budoucnu je zapotřebí vyrábět substrátově specifická farmaka s epigenetickými účinky a začít jejich testování na lidech. Epigenetika nám může napomoci při překonávání farmakorezistence duševních poruch, případně v jejich časné detekci a prevenci.
Epigenetics deals with the influence of external as well as intrinsic factors on the DNA function in a given organism without t he chan- ge of DNA sequence. Epigenetic effects are significant in both currently existing cells and their daughter cells. This holds tr ue for an individual organism as well as intergenerational transmission of acquired signs. Histone acetylation and DNA methylat ion are considered as the most important epigenetic mechanisms. In addition to this, other molecular procedures have already been recognized, including non-coding RNA molecules which influence gene expression. Non-coding RNA is mostly synthesized based on so called nonsense DNA. Epigenetic research has only been performed on in vitro tissues, experimental animals and brain tissue of decea- sed psychiatric patients so far. Clinical epigenetic studies in the treatment of mental disorders are lacking. Epigenetic thera py of cognitive disorders, schizophrenia, and mood disorders seems to be promising for the future. In this effort, both existing medi caments (valproate, clozapine, sulpiride, escitalopram, lithium) and newly synthesized chemical substances can be utilized. The problem is that epigenetic effects of currently known substances are not specific for individual parts of the brain, brain cells, enzymes or ge nes. This may induce serious adverse effects. In the future, it is necessary to produce substrate-specific epigenetic medicaments, and start epigenetic cli- nical studies. Epigenetics can help us to overcome treatment resistance of mental disorders, and possibly detect and prevent th em early.
- Klíčová slova
- léčba, epigenetika, farmakorezistence,
- MeSH
- Alzheimerova nemoc genetika patologie terapie MeSH
- cytosin biosyntéza MeSH
- DNA modifikační methylasy MeSH
- duševní poruchy * diagnóza farmakoterapie prevence a kontrola MeSH
- epigenomika * metody trendy MeSH
- exozómy MeSH
- exprese genu MeSH
- histony biosyntéza MeSH
- klinické zkoušky jako téma MeSH
- krysa rodu rattus MeSH
- kyselina valproová terapeutické užití MeSH
- léková rezistence MeSH
- lidé MeSH
- psychofarmakologie trendy MeSH
- RNA dlouhá nekódující dějiny genetika MeSH
- schizofrenie genetika patologie terapie MeSH
- synapse fyziologie účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- lidé MeSH
- zvířata MeSH
Monkeypox is a disease with pandemic potential. It is caused by the monkeypox virus (MPXV), a double-stranded DNA virus from the Poxviridae family, that replicates in the cytoplasm and must encode for its own RNA processing machinery including the capping machinery. Here, we present crystal structures of its 2'-O-RNA methyltransferase (MTase) VP39 in complex with the pan-MTase inhibitor sinefungin and a series of inhibitors that were discovered based on it. A comparison of this 2'-O-RNA MTase with enzymes from unrelated single-stranded RNA viruses (SARS-CoV-2 and Zika) reveals a conserved sinefungin binding mode, implicating that a single inhibitor could be used against unrelated viral families. Indeed, several of our inhibitors such as TO507 also inhibit the coronaviral nsp14 MTase.
- MeSH
- COVID-19 * MeSH
- infekce virem zika * MeSH
- lidé MeSH
- methyltransferasy metabolismus MeSH
- RNA virová genetika MeSH
- RNA MeSH
- SARS-CoV-2 genetika MeSH
- virové nestrukturální proteiny chemie MeSH
- virus opičích neštovic genetika metabolismus MeSH
- virus zika * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Radiation exposure can evoke cellular stress responses. Emerging recognition that long non-coding RNAs (lncRNAs) act as regulators of gene expression has broadened the spectra of molecules controlling the genomic landscape upon alterations in environmental conditions. Knowledge of the mechanisms responding to low dose irradiation (LDR) exposure is very limited yet most likely involve subtle ancillary molecular pathways other than those protecting the cell from direct cellular damage. The discovery that transcription of the lncRNA PARTICLE (promoter of MAT2A- antisense radiation-induced circulating lncRNA; PARTICL) becomes dramatically instigated within a day after LDR exposure introduced a new gene regulator onto the biological landscape. PARTICLE affords an RNA binding platform for genomic silencers such as DNA methyltransferase 1 and histone tri-methyltransferases to reign in the expression of tumor suppressors such as its neighboring MAT2A in cis as well as WWOX in trans. In silico evidence offers scope to speculate that PARTICLE exploits the abundance of Hoogsten bonds that exist throughout mammalian genomes for triplex formation, presumably a vital feature within this RNA silencer. PARTICLE may provide a buffering riboswitch platform for S-adenosylmethionine. The correlation of PARTICLE triplex formation sites within tumor suppressor genes and their abundance throughout the genome at cancer-related hotspots offers an insight into potential avenues worth exploring in future therapeutic endeavors.
- MeSH
- dávka záření MeSH
- DNA-(cytosin-5)-methyltransferasa 1 genetika MeSH
- genom lidský účinky záření MeSH
- genomika MeSH
- histonové methyltransferasy genetika MeSH
- lidé MeSH
- methioninadenosyltransferasa genetika MeSH
- nádorové supresorové proteiny genetika MeSH
- nádory genetika radioterapie MeSH
- oxidoreduktasa obsahující WW doménu genetika MeSH
- promotorové oblasti (genetika) genetika MeSH
- radiační expozice škodlivé účinky MeSH
- regulace genové exprese u nádorů účinky záření MeSH
- RNA dlouhá nekódující genetika MeSH
- RNA interference účinky záření 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
Coronaviral methyltransferases (MTases), nsp10/16 and nsp14, catalyze the last two steps of viral RNA-cap creation that takes place in cytoplasm. This cap is essential for the stability of viral RNA and, most importantly, for the evasion of innate immune system. Non-capped RNA is recognized by innate immunity which leads to its degradation and the activation of antiviral immunity. As a result, both coronaviral MTases are in the center of scientific scrutiny. Recently, X-ray and cryo-EM structures of both enzymes were solved even in complex with other parts of the viral replication complex. High-throughput screening as well as structure-guided inhibitor design have led to the discovery of their potent inhibitors. Here, we critically summarize the tremendous advancement of the coronaviral MTase field since the beginning of COVID pandemic.
- MeSH
- aminokyseliny chemie MeSH
- antivirové látky chemie farmakologie MeSH
- Coronavirus účinky léků enzymologie genetika MeSH
- lidé MeSH
- methyltransferasy antagonisté a inhibitory chemie metabolismus MeSH
- metylace MeSH
- molekulární konformace MeSH
- molekulární modely MeSH
- molekulární struktura MeSH
- objevování léků MeSH
- RNA virová chemie genetika metabolismus MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- vazebná místa MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
RNA polymerase II (RNA pol II) is not only the fundamental enzyme for gene expression but also the central coordinator of co-transcriptional processing. RNA pol II associates with a large number of enzymes and protein/RNA-binding factors through its C-terminal domain (CTD) that consists of tandem repeats of the heptapeptide consensus Y(1)S(2)P(3) T(4)S(5)P(6)S(7). The CTD is posttranslationally modified, yielding specific patterns (often called the CTD code) that are recognized by appropriate factors in coordination with the transcription cycle. Serine phosphorylations are currently the best characterized elements of the CTD code; however, the roles of the proline isomerization and other modifications of the CTD remain poorly understood. The dynamic remodeling of the CTD modifications by kinases, phosphatases, isomerases, and other enzymes introduce changes in the CTD structure and dynamics. These changes serve as structural switches that spatially and temporally regulate the binding of processing factors. Recent structural studies of the CTD bound to various proteins have revealed the basic rules that govern the recognition of these switches and shed light on the roles of these protein factors in the assemblies of the processing machineries.
- MeSH
- genetická transkripce MeSH
- methyltransferasy metabolismus MeSH
- peptidylprolylisomerasa metabolismus MeSH
- posttranslační úpravy proteinů * MeSH
- prolin metabolismus MeSH
- proteiny vázající RNA genetika metabolismus MeSH
- RNA-polymerasa II * chemie genetika metabolismus MeSH
- Saccharomyces cerevisiae enzymologie genetika MeSH
- sekvence aminokyselin MeSH
- terciární struktura proteinů MeSH
- transportní proteiny metabolismus MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
