Extravasation of monocytes into tissue and to the site of injury is a fundamental immunological process, which requires rapid responses via post translational modifications (PTM) of proteins. Protein arginine methyltransferase 7 (PRMT7) is an epigenetic factor that has the capacity to mono-methylate histones on arginine residues. Here we show that in chronic obstructive pulmonary disease (COPD) patients, PRMT7 expression is elevated in the lung tissue and localized to the macrophages. In mouse models of COPD, lung fibrosis and skin injury, reduced expression of PRMT7 associates with decreased recruitment of monocytes to the site of injury and hence less severe symptoms. Mechanistically, activation of NF-κB/RelA in monocytes induces PRMT7 transcription and consequential mono-methylation of histones at the regulatory elements of RAP1A, which leads to increased transcription of this gene that is responsible for adhesion and migration of monocytes. Persistent monocyte-derived macrophage accumulation leads to ALOX5 over-expression and accumulation of its metabolite LTB4, which triggers expression of ACSL4 a ferroptosis promoting gene in lung epithelial cells. Conclusively, inhibition of arginine mono-methylation might offer targeted intervention in monocyte-driven inflammatory conditions that lead to extensive tissue damage if left untreated.
- MeSH
- arginin metabolismus MeSH
- chronická obstrukční plicní nemoc * genetika MeSH
- histony metabolismus MeSH
- intracelulární signální peptidy a proteiny MeSH
- lidé MeSH
- monocyty metabolismus MeSH
- myši MeSH
- proteinarginin-N-methyltransferasy * metabolismus MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
The oncogenic Epstein-Barr virus (EBV) evades the immune system but has an Achilles heel: its genome maintenance protein EBNA1. Indeed, EBNA1 is essential for viral genome maintenance but is also highly antigenic. Hence, EBV seemingly evolved a system in which the glycine-alanine repeat (GAr) of EBNA1 limits the translation of its own mRNA to the minimal level to ensure its essential function, thereby, at the same time, minimizing immune recognition. Therefore, defining intervention points at which to interfere with GAr-based inhibition of translation is an important step to trigger an immune response against EBV-carrying cancers. The host protein nucleolin (NCL) plays a critical role in this process via a direct interaction with G-quadruplexes (G4) formed in the GAr-encoding sequence of the viral EBNA1 mRNA. Here we show that the C-terminal arginine-glycine-rich (RGG) motif of NCL is crucial for its role in GAr-based inhibition of translation by mediating interaction of NCL with G4 of EBNA1 mRNA. We also show that this interaction depends on the type I arginine methyltransferase family, notably PRMT1 and PRMT3: drugs or small interfering RNA that target these enzymes prevent efficient binding of NCL on G4 of EBNA1 mRNA and relieve GAr-based inhibition of translation and of antigen presentation. Hence, this work defines type I arginine methyltransferases as therapeutic targets to interfere with EBNA1 and EBV immune evasion.
- MeSH
- imunitní systém metabolismus MeSH
- infekce onkogenními viry * farmakoterapie metabolismus MeSH
- infekce virem Epsteina-Barrové * genetika MeSH
- lidé MeSH
- messenger RNA metabolismus MeSH
- onkogenní viry genetika metabolismus MeSH
- proteinarginin-N-methyltransferasy MeSH
- represorové proteiny MeSH
- virus Epsteinův-Barrové - jaderné antigeny genetika metabolismus MeSH
- virus Epsteinův-Barrové * genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Infection with hepatitis B virus (HBV) often leads to development of chronic liver disease. In fact, 10% of infected adults and almost 90% of infected infants develop chronic hepatitis B associated with severe liver diseases, including acute liver failure, liver cirrhosis or hepatocellular carcinoma. At present there is no effective cure for chronic hepatitis B. The current treatment of chronically infected patients is long-term, expensive and relies on treatment with nucleos(t)ide analogs in combination with immune therapies, that frequently lead to adverse side effects. Recently, the National Institute of Health proposed strategic plan for Trans-NIH research to cure hepatitis B. The key priority is better understanding of HBV life cycle and its interactions with host cell. Due to the fact that HBV is a small double stranded DNA virus encoding only a limited number of proteins, HBV replication widely relies on host cell pathways and proteins. As demonstrated by numerous reports, HBV core protein (HBc) which is the main component of viral nucleocapsid, plays multiple roles in HBV life cycle and is engaged in many protein interaction networks of the host cell. Several recent studies have shown that HBV proteins can be modified by different types of posttranslational modifications (PTMs) that affect their protein-protein interactions, subcellular localization and function. In this review, we discuss diverse PTMs of HBc and their role in regulation of HBc function in the context of HBV replication and pathogenesis.
In mammals, protein arginine methyltransferase 5, PRMT5, is the main type II enzyme responsible for the majority of symmetric dimethylarginine formation in polypeptides. Recent study reported that PRMT5 restricts Hepatitis B virus (HBV) replication through epigenetic repression of HBV DNA transcription and interference with encapsidation of pregenomic RNA. Here we demonstrate that PRMT5 interacts with the HBV core (HBc) protein and dimethylates arginine residues within the arginine-rich domain (ARD) of the carboxyl-terminus. ARD consists of four arginine rich subdomains, ARDI, ARDII, ARDIII and ARDIV. Mutation analysis of ARDs revealed that arginine methylation of HBc required the wild-type status of both ARDI and ARDII. Mass spectrometry analysis of HBc identified multiple potential ubiquitination, methylation and phosphorylation sites, out of which lysine K7 and arginines R150 (within ARDI) and R156 (outside ARDs) were shown to be modified by ubiquitination and methylation, respectively. The HBc symmetric dimethylation appeared to be linked to serine phosphorylation and nuclear import of HBc protein. Conversely, the monomethylated HBc retained in the cytoplasm. Thus, overexpression of PRMT5 led to increased nuclear accumulation of HBc, and vice versa, down-regulation of PRMT5 resulted in reduced levels of HBc in nuclei of transfected cells. In summary, we identified PRMT5 as a potent controller of HBc cell trafficking and function and described two novel types of HBc post-translational modifications (PTMs), arginine methylation and ubiquitination.
- MeSH
- fosforylace MeSH
- hmotnostní spektrometrie MeSH
- lidé MeSH
- metylace MeSH
- proteinarginin-N-methyltransferasy metabolismus fyziologie MeSH
- replikace viru fyziologie MeSH
- subcelulární frakce metabolismus MeSH
- ubikvitinace MeSH
- virus hepatitidy B enzymologie fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
DNA damage response (DDR) in ribosomal genes and mechanisms of DNA repair in embryonic stem cells (ESCs) are less explored nuclear events. DDR in ESCs should be unique due to their high proliferation rate, expression of pluripotency factors, and specific chromatin signature. Given short population doubling time and fast progress through G1 phase, ESCs require a sustained production of rRNA, which leads to the formation of large and prominent nucleoli. Although transcription of rRNA in the nucleolus is relatively well understood, little is known about DDR in this nuclear compartment. Here, we directed formation of double-strand breaks in rRNA genes with I- PpoI endonuclease, and we studied nucleolar morphology, DDR, and chromatin modifications. We observed a pronounced formation of I- PpoI-induced nucleolar caps, positive on BRCA1, NBS1, MDC1, γH2AX, and UBF1 proteins. We showed interaction of nucleolar protein TCOF1 with HDAC1 and TCOF1 with CARM1 after DNA injury. Moreover, H3R17me2a modification mediated by CARM1 was found in I- PpoI-induced nucleolar caps. Finally, we report that heterochromatin protein 1 is not involved in DNA repair of nucleolar caps.
- MeSH
- acetylace MeSH
- arginin metabolismus MeSH
- buněčné jadérko genetika ultrastruktura MeSH
- buněčné linie MeSH
- dvouřetězcové zlomy DNA * MeSH
- embryonální kmenové buňky metabolismus ultrastruktura MeSH
- fosfoproteiny metabolismus MeSH
- geny rRNA MeSH
- histondeacetylasa 1 metabolismus MeSH
- histony metabolismus MeSH
- jaderné proteiny metabolismus MeSH
- metylace MeSH
- myši MeSH
- oprava DNA MeSH
- proteinarginin-N-methyltransferasy metabolismus MeSH
- RNA ribozomální genetika metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
CARM1 interacts with numerous transcription factors to mediate cellular processes, especially gene expression. This is important for the maintenance of ESC pluripotency or intervention to tumorigenesis. Here, we studied epigenomic effects of two potential CARM1 modulators: an activator (EML159) and an inhibitor (ellagic acid dihydrate, EA). We examined nuclear morphology in human and mouse embryonic stem cells (hESCs, mESCs), as well as in iPS cells. The CARM1 modulators did not function similarly in all cell types. EA decreased the levels of the pluripotency markers, OCT4 and NANOG, particularly in iPSCs, whereas the levels of these proteins increased after EML159 treatment. EML159 treatment of mouse ESCs led to decreased levels of OCT4 and NANOG, which was accompanied by an increased level of Endo-A. The same trend was observed for NANOG and Endo-A in hESCs affected by EML159. Interestingly, EA mainly changed epigenetic features of nucleoli because a high level of arginine asymmetric di-methylation in the nucleoli of hESCs was reduced after EA treatment. ChIP-PCR of ribosomal genes confirmed significantly reduced levels of H3R17me2a, in both the promoter region of ribosomal genes and rDNA encoding 28S rRNA, after EA addition. Moreover, EA treatment changed the nuclear pattern of AgNORs (silver-stained nucleolus organizer regions) in all cell types studied. In EA-treated ESCs, AgNOR pattern was similar to the pattern of AgNORs after inhibition of RNA pol I by actinomycin D. Together, inhibitory effect of EA on arginine methylation and effect on related morphological parameters was especially observed in compartment of nucleoli.
- MeSH
- buněčné jadérko účinky léků fyziologie ultrastruktura MeSH
- buněčné linie MeSH
- embryonální kmenové buňky účinky léků fyziologie ultrastruktura MeSH
- epigeneze genetická účinky léků fyziologie MeSH
- kyselina ellagová farmakologie MeSH
- lidé MeSH
- myši MeSH
- proteinarginin-N-methyltransferasy antagonisté a inhibitory fyziologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Protein arginine methyltransferases (PRMTs) are responsible for symmetric and asymmetric methylation of arginine residues of nuclear and cytoplasmic proteins. In the nucleus, PRMTs belong to important chromatin modifying enzymes of immense functional significance that affect gene expression, splicing and DNA repair. By time-lapse microscopy we have studied the sub-cellular localization and kinetics of PRMT1 after inhibition of PRMT1 and after irradiation. Both transiently expressed and endogenous PRMT1 accumulated in cytoplasmic bodies that were located in the proximity of the cell nucleus. The shape and number of these bodies were stable in untreated cells. However, when cell nuclei were microirradiated by UV-A, the mobility of PRMT1 cytoplasmic bodies increased, size was reduced, and disappeared within approximately 20 min. The same response occurred after γ-irradiation of the whole cell population, but with delayed kinetics. Treatment with PRMT1 inhibitors induced disintegration of these PRMT1 cytoplasmic bodies and prevented formation of 53BP1 nuclear bodies (NBs) that play a role during DNA damage repair. The formation of 53BP1 NBs was not influenced by PRMT1 overexpression. Taken together, we show that PRMT1 concentrates in cytoplasmic bodies, which respond to DNA injury in the cell nucleus, and to treatment with various PRMT1 inhibitors.
- MeSH
- chromozomální proteiny, nehistonové genetika metabolismus MeSH
- cytoplazma enzymologie MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- HeLa buňky MeSH
- intracelulární signální peptidy a proteiny genetika metabolismus MeSH
- lidé MeSH
- myši MeSH
- poškození DNA * MeSH
- proteinarginin-N-methyltransferasy antagonisté a inhibitory genetika metabolismus MeSH
- represorové proteiny antagonisté a inhibitory genetika metabolismus MeSH
- ultrafialové záření * MeSH
- záření gama * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Protein arginine methyltransferase 3 (PRMT3) is a cytosolic enzyme that catalyzes the formation of mono- and asymmetric dimethyl arginines, with ribosomal protein (RP) S2 as its main in vivo substrate. The interplay of PRMT3-RPS2 homologs in yeast is important for regulating the ribosomal subunit ratio and assembly. Prmt3-null mice display slower embryonic growth and development, although this phenotype is milder than in mouse RP gene knockouts. Defects in ribosome maturation are the hallmark of Diamond-Blackfan anemia (DBA). Sequencing of the PRMT3 gene in patients from the Czech DBA registry revealed a heterozygous mutation encoding the Tyr87Cys substitution. Although later analysis excluded this mutation as the cause of disease, we anticipated that this substitution might be important for PRMT3 function and decided to study it in detail. Tyr87 resides in a highly conserved substrate binding domain and has been predicted to be phosphorylated. To address the impact of putative Tyr87 phosphorylation on PRMT3 properties, we constructed two additional PRMT3 variants, Tyr87Phe and Tyr87Glu PRMT3, mimicking non-phosphorylated and phosphorylated Tyr87, respectively. The Tyr87Cys and Tyr87Glu-PRMT3 variants had markedly decreased affinity to RPS2 and, consequently, reduced enzymatic activity compared to the wild-type enzyme. The activity of the Tyr87Phe-PRMT3 mutant remained unaffected. No evidence of Tyr87 phosphorylation was found using mass spectrometric analysis of purified PRMT3, although phosphorylation of serines 25 and 27 was observed. In conclusion, Tyr87 is important for the interaction between PRMT3 and RPS2 and for its full enzymatic activity.
- MeSH
- Diamondova-Blackfanova anemie enzymologie genetika MeSH
- HeLa buňky MeSH
- interakční proteinové domény a motivy MeSH
- kinetika MeSH
- lidé MeSH
- metylace MeSH
- missense mutace MeSH
- molekulární sekvence - údaje MeSH
- mutageneze cílená MeSH
- myši MeSH
- proteinarginin-N-methyltransferasy chemie genetika metabolismus MeSH
- rekombinantní proteiny chemie genetika metabolismus MeSH
- ribozomální proteiny metabolismus MeSH
- sekvence aminokyselin MeSH
- substituce aminokyselin MeSH
- tyrosin chemie genetika MeSH
- vazba proteinů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- arginin * analogy a deriváty metabolismus MeSH
- dialýza ledvin metody využití MeSH
- financování organizované MeSH
- homocystein metabolismus MeSH
- hyperhomocysteinemie * etiologie komplikace metabolismus MeSH
- kardiorenální syndrom metabolismus MeSH
- kreatinin izolace a purifikace metabolismus MeSH
- lidé MeSH
- nemoci ledvin * etiologie metabolismus MeSH
- proteinarginin-N-methyltransferasy izolace a purifikace metabolismus MeSH
- statistika jako téma MeSH
- studie případů a kontrol MeSH
- věkové faktory MeSH
- vyšetření funkce ledvin metody využití MeSH
- Check Tag
- lidé MeSH
