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1.
Toxicol Lett ; 321: 131-137, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31877331

RESUMO

Prior exposures to chemicals/agents may alter epigenome in such a way that subsequent exposure to the same or different xenobiotic would produce different responses. Understanding the mechanism for this "priming" effect is of clinical significance in avoiding adverse drug-drug interactions. Here we reported a dramatic priming effect of dimethyl sulfoxide (DMSO) on pregnane X receptor (PXR)-mediated gene regulations and analyzed the underpinning epigenetic mechanism. We showed that DMSO (1.25-2.5 %) pretreatment has a profound effect in enhancing the expression of PXR target genes. This priming effect persisted up to 48 h. Mechanistically, DMSO pretreatment reduced H4K12 acetylation and therefore enhanced the subsequent rifampicin stimulated histone H4R3 methylation on the regulatory region of PXR target gene CYP3A4. We showed that protein arginine methyltransferase 1 (PRMT1), which methylates H4R3, was important for priming by DMSO. Inhibition of methyltransferase by the pharmacological inhibitor adenosine dialehyde (AdoX), or RNAi knockdown of PRMT1, abolished the DMSO priming effects. On the other hand, Trichostation A (TSA) pretreatment, which increases histone acetylation and therefore suppresses H4R3 methylation, also abolished the DMSO priming effects. Based on the above observation, we proposed a model of sequential order of histone methylation and acetylation on the transcription "relay".


Assuntos
Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Metilação de DNA/efeitos dos fármacos , Dimetil Sulfóxido/toxicidade , Epigênese Genética/efeitos dos fármacos , Hepatócitos/efeitos dos fármacos , Histonas/metabolismo , Receptor de Pregnano X/agonistas , Acetilação , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Citocromo P-450 CYP3A/genética , Citocromo P-450 CYP3A/metabolismo , Células Hep G2 , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Metilação , Receptor de Pregnano X/genética , Receptor de Pregnano X/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Fatores de Tempo
2.
J Biochem ; 166(6): 517-527, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31778188

RESUMO

Dysregulation of microRNAs (miRNAs) plays a key role during the pathogenesis of chemoresistance in lung cancer (LCa). Previous study suggests that miR-324-5p may serve as a unique miRNA signature for LCa, but its role and the corresponding molecular basis remain largely explored. Herein, we report that miR-324-5p expression was significantly increased in cisplatin (CDDP)-resistant LCa tissues and cells, and this upregulation predicted a poor post-chemotherapy prognosis in LCa patients. miR-324-5p was further shown to impact CDDP response: Ectopic miR-324-5p expression in drug-naïve LCa cells was sufficient to attenuate sensitivity to CDDP and to confer more robust tumour growth in CDDP-challenged nude mice. Conversely, ablation of miR-324-5p expression in resistant cells effectively potentiated CDDP-suppressed cell growth in vitro and in vivo. Using multiple approaches, we further identified the tumour suppressor FBXO11 as the direct down-stream target of miR-324-5p. Stable expression of FBXO11 could abrogate the pro-survival effects of miR-324-5p in CDDP-challenged LCa cells. Together, these findings suggest that miR-324-5p upregulation mediates, at least partially, the CDDP resistance by directly targeting FBXO11 signalling in LCa cells. In-depth elucidation of the molecular basis underpinning miR-324-5p action bears potential implications for mechanism-based strategies to improve CDDP responses in LCa.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Cisplatino/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteínas F-Box/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , MicroRNAs/farmacologia , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Regulação para Cima/efeitos dos fármacos , Células A549 , Animais , Antineoplásicos/farmacologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma Pulmonar de Células não Pequenas/patologia , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Nus , Neoplasias Experimentais/tratamento farmacológico , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/patologia , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Transdução de Sinais/efeitos dos fármacos , Relação Estrutura-Atividade
3.
Nat Commun ; 10(1): 4705, 2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624244

RESUMO

DNA methylation, repressive histone marks, and PIWI-interacting RNA (piRNA) are essential for the control of retrotransposon silencing in the mammalian germline. However, it remains unknown how these repressive epigenetic pathways crosstalk to ensure retrotransposon silencing in the male germline. Here, we show that UHRF1 is responsible for retrotransposon silencing and cooperates with repressive epigenetic pathways in male germ cells. Conditional loss of UHRF1 in postnatal germ cells causes DNA hypomethylation, upregulation of retrotransposons, the activation of a DNA damage response, and switches in the global chromatin status, leading to complete male sterility. Furthermore, we show that UHRF1 interacts with PRMT5, an arginine methyltransferase, to regulate the repressive histone arginine modifications (H4R3me2s and H3R2me2s), and cooperates with the PIWI pathway during spermatogenesis. Collectively, UHRF1 regulates retrotransposon silencing in male germ cells and provides a molecular link between DNA methylation, histone modification, and the PIWI pathway in the germline.


Assuntos
Proteínas Argonauta/genética , Proteínas Estimuladoras de Ligação a CCAAT/genética , Metilação de DNA , Proteína-Arginina N-Metiltransferases/genética , Retroelementos/genética , Espermatozoides/metabolismo , Ubiquitina-Proteína Ligases/genética , Animais , Proteínas Argonauta/metabolismo , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Feminino , Inativação Gênica , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Ligação Proteica , Proteína-Arginina N-Metiltransferases/metabolismo , Espermatogênese/genética , Ubiquitina-Proteína Ligases/metabolismo
4.
Neoplasma ; 66(6): 918-929, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31607134

RESUMO

Protein arginine methyltransferase 1 (PRMT1) is dysregulated in a number of human cancers. Herein, we report that PRMT1 expression is directly associated with epithelial-mesenchymal transition (EMT) in hepatic carcinoma cells. Firstly, we find that PRMT1 expression is higher in hepatic carcinoma tissues than that in normal liver tissues at both mRNA and protein levels, and higher expression of PRMT1 correlates with poor survival in liver tumors. The data in vitro reveals that PRMT1 knockdown inhibits the abilities of proliferation, migration and invasion, while PRMT1 overexpression promotes the above behaviors in hepatic carcinoma cells. Further studies indicate that PRMT1 knockdown remarkably decreases the expression of mesenchymal markers including Vimentin, Snail and N-cadherin, and upregulates expression of epithelial markers E-cadherin. Conversely, PRMT1 overexpression results in the opposite effects. Additionally, we identified that PRMT1 knockdown resulted in downregulation of TGF-ß1, p-Smad2 and p-Smad3, while PRMT1 overexpression activated TGF-ß1, p-Smad2 and p-Smad3. These findings suggest that PRMT1 promotes EMT in hepatic carcinoma cells probably via TGF-ß1/Smad pathway, and might represent a novel anti-liver cancer strategy.


Assuntos
Carcinoma Hepatocelular/metabolismo , Transição Epitelial-Mesenquimal , Neoplasias Hepáticas/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular , Técnicas de Silenciamento de Genes , Humanos , Neoplasias Hepáticas/patologia , Transdução de Sinais , Proteína Smad2/metabolismo , Proteína Smad3/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
5.
Endocrinology ; 160(12): 2773-2786, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31555811

RESUMO

Protein arginine methyltransferases (PRMTs) are enzymes that regulate the evolutionarily conserved process of arginine methylation. It has been reported that PRMTs are involved in many metabolic regulatory pathways. However, until now, their roles in adipocyte function, especially browning and thermogenesis, have not been evaluated. Even though Prmt1 adipocyte-specific-deleted mice (Prmt1fl/flAQcre) appeared normal at basal level, following cold exposure or ß-adrenergic stimulation, impaired induction of the thermogenic program was observed in both the interscapular brown adipose tissue and inguinal white adipose tissue of Prmt1fl/flAQcre mice compared with littermate controls. Different splicing variants of Prmt1 have been reported. Among them, PRMT1 variant 1 and PRMT1 variant 2 (PRMT1V2) are well conserved between humans and mice. Both variants contribute to the activation of thermogenic fat, with PRMT1V2 playing a more dominant role. Mechanistic studies using cultured murine and human adipocytes revealed that PRMT1V2 mediates thermogenic fat activation through PGC1α, a transcriptional coactivator that has been shown to play a key role in mitochondrial biogenesis. To our knowledge, our data are the first to demonstrate that PRMT1 plays a regulatory role in thermogenic fat function. These findings suggest that modulating PRMT1 activity may represent new avenues to regulate thermogenic fat and mediate energy homeostasis. This function is conserved in human primary adipocytes, suggesting that further investigation of this pathway may ultimately lead to therapeutic strategies against human obesity and associated metabolic disorders.


Assuntos
Adipócitos Bege/enzimologia , Adipócitos Marrons/enzimologia , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Termogênese , Aclimatação , Animais , Feminino , Regulação da Expressão Gênica , Humanos , Masculino , Camundongos , Cultura Primária de Células
6.
Nat Commun ; 10(1): 3761, 2019 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-31434880

RESUMO

The mechanisms underlying how cells subjected to genotoxic stress reestablish reduction-oxidation (redox) homeostasis to scavenge genotoxic stress-induced reactive oxygen species (ROS), which maintains the physiological function of cellular processes and cell survival, remain unclear. Herein, we report that, via a TCF-independent mechanism, genotoxic stress induces the enrichment of ß-catenin in chromatin, where it forms a complex with ATM phosphorylated-JDP2 and PRMT5. This elicits histone H3R2me1/H3R2me2s-induced transcriptional activation by the recruitment of the WDR5/MLL methyltransferase complexes and concomitant H3K4 methylation at the promoters of multiple genes in GSH-metabolic cascade. Treatment with OICR-9429, a small-molecule antagonist of the WDR5-MLL interaction, inhibits the ß-catenin/JDP2/PRMT5 complex-reestablished GSH metabolism, leading to a lethal increase in the already-elevated levels of ROS in the genotoxic-agent treated cancer cells. Therefore, our results unveil a plausible role for ß-catenin in reestablishing redox homeostasis upon genotoxic stress and shed light on the mechanisms of inducible chemotherapy resistance in cancer.


Assuntos
Dano ao DNA/fisiologia , Glutationa/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/metabolismo , beta Catenina/metabolismo , Células A549 , Animais , Compostos de Bifenilo/farmacologia , Linhagem Celular Tumoral , Cromatina , Di-Hidropiridinas/farmacologia , Feminino , Glutationa/efeitos dos fármacos , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Homeostase , Humanos , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteína de Leucina Linfoide-Mieloide/metabolismo , Neoplasias/metabolismo , Regiões Promotoras Genéticas , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Ativação Transcricional
7.
EMBO J ; 38(15): e100986, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31267554

RESUMO

Aberrant transcription-associated RNA:DNA hybrid (R-loop) formation often causes catastrophic conflicts during replication, resulting in DNA double-strand breaks and genomic instability. Preventing such conflicts requires hybrid dissolution by helicases and/or RNase H. Little is known about how such helicases are regulated. Herein, we identify DDX5, an RGG/RG motif-containing DEAD-box family RNA helicase, as crucial player in R-loop resolution. In vitro, recombinant DDX5 resolves R-loops in an ATP-dependent manner, leading to R-loop degradation by the XRN2 exoribonuclease. DDX5-deficient cells accumulate R-loops at loci with propensity to form such structures based on RNA:DNA immunoprecipitation (DRIP)-qPCR, causing spontaneous DNA double-strand breaks and hypersensitivity to replication stress. DDX5 associates with XRN2 and resolves R-loops at transcriptional termination regions downstream of poly(A) sites, to facilitate RNA polymerase II release associated with transcriptional termination. Protein arginine methyltransferase 5 (PRMT5) binds and methylates DDX5 at its RGG/RG motif. This motif is required for DDX5 interaction with XRN2 and repression of cellular R-loops, but not essential for DDX5 helicase enzymatic activity. PRMT5-deficient cells accumulate R-loops, resulting in increased formation of γH2AX foci. Our findings exemplify a mechanism by which an RNA helicase is modulated by arginine methylation to resolve R-loops, and its potential role in regulating transcription.


Assuntos
RNA Helicases DEAD-box/química , RNA Helicases DEAD-box/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , RNA/química , Motivos de Aminoácidos , Arginina/metabolismo , Linhagem Celular , DNA/metabolismo , Exorribonucleases/metabolismo , Células HEK293 , Humanos , Metilação , Proteína-Arginina N-Metiltransferases/genética , RNA/metabolismo , RNA Polimerase II/metabolismo
8.
Int J Mol Sci ; 20(13)2019 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-31284549

RESUMO

Protein post-translational modifications (PTMs) in eukaryotic cells play important roles in the regulation of functionalities of the proteome and in the tempo-spatial control of cellular processes. Most PTMs enact their regulatory functions by affecting the biochemical properties of substrate proteins such as altering structural conformation, protein-protein interaction, and protein-nucleic acid interaction. Amid various PTMs, arginine methylation is widespread in all eukaryotic organisms, from yeasts to humans. Arginine methylation in many situations can drastically or subtly affect the interactions of substrate proteins with their partnering proteins or nucleic acids, thus impacting major cellular programs. Recently, arginine methylation has become an important regulator of the formation of membrane-less organelles inside cells, a phenomenon of liquid-liquid phase separation (LLPS), through altering π-cation interactions. Another unique feature of arginine methylation lies in its impact on cellular physiology through its downstream amino acid product, asymmetric dimethylarginine (ADMA). Accumulation of ADMA in cells and in the circulating bloodstream is connected with endothelial dysfunction and a variety of syndromes of cardiovascular diseases. Herein, we review the current knowledge and understanding of protein arginine methylation in regards to its canonical function in direct protein regulation, as well as the biological axis of protein arginine methylation and ADMA biology.


Assuntos
Arginina/análogos & derivados , Arginina/metabolismo , Proteínas/metabolismo , Animais , Arginina/química , Humanos , Metaboloma , Metilação , Proteína-Arginina N-Metiltransferases/metabolismo
9.
Mol Plant Microbe Interact ; 32(10): 1291-1302, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31216220

RESUMO

The genomes of all eukaryotic organisms, from small unicellular yeasts to humans, include members of the protein arginine methyltransferase (PRMT) family. These enzymes affect gene transcription, cellular signaling, and function through the posttranslational methylation of arginine residues. Mis-regulation of PRMTs results in serious developmental defects, disease, or death, illustrating the importance of these enzymes to cellular processes. Plant genomes encode almost the full complement of PRMTs found in other higher organisms, plus an additional PRMT found uniquely in plants, PRMT10. Here, we investigate the role of these highly conserved PRMTs in a process that is unique to perennial plants-the development of symbiosis with ectomycorrhizal fungi. We show that PRMT expression and arginine methylation is altered in the roots of the model tree Eucalyptus grandis by the presence of its ectomycorrhizal fungal symbiont Pisolithus albus. Further, using transgenic modifications, we demonstrate that E. grandis-encoded PRMT1 and PRMT10 have important but opposing effects in promoting this symbiosis. In particular, the plant-specific EgPRMT10 has a potential role in the expression of plant hormone pathways during the colonization process and its overexpression reduces fungal colonization success.


Assuntos
Eucalyptus , Regulação da Expressão Gênica de Plantas , Micorrizas , Proteína-Arginina N-Metiltransferases , Transdução de Sinais , Simbiose , Basidiomycota/fisiologia , Humanos , Micorrizas/fisiologia , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Simbiose/fisiologia
10.
Life Sci Alliance ; 2(3)2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31160378

RESUMO

Protein arginine methylation is an important means by which protein function can be regulated. In the budding yeast, this modification is catalyzed by the major protein arginine methyltransferase Hmt1. Here, we provide evidence that the Hmt1-mediated methylation of Rpc31, a subunit of RNA polymerase III, plays context-dependent roles in tRNA gene transcription: under conditions optimal for growth, it positively regulates tRNA gene transcription, and in the setting of stress, it promotes robust transcriptional repression. In the context of stress, methylation of Rpc31 allows for its optimal interaction with RNA polymerase III global repressor Maf1. Interestingly, mammalian Hmt1 homologue is able to methylate one of Rpc31's human homologue, RPC32ß, but not its paralogue, RPC32α. Our data led us to propose an efficient model whereby protein arginine methylation facilitates metabolic economy and coordinates protein-synthetic capacity.


Assuntos
Arginina/metabolismo , RNA de Transferência , Estresse Fisiológico/genética , Transcrição Genética , Sequência de Aminoácidos , Regulação Fúngica da Expressão Gênica , Metilação , Mutação , Ligação Proteica , Subunidades Proteicas/metabolismo , Proteína-Arginina N-Metiltransferases/química , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , RNA Polimerase III/química , RNA Polimerase III/genética , RNA Polimerase III/metabolismo , Proteínas Repressoras/química , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo
11.
Gastroenterology ; 157(3): 744-759.e4, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31154022

RESUMO

BACKGROUND & AIMS: Many genetic and environmental factors, including family history, dietary fat, and inflammation, increase risk for colon cancer development. Peroxisome proliferator-activated receptor alpha (PPARα) is a nuclear receptor that regulates systemic lipid homeostasis. We explored the role of intestinal PPARα in colon carcinogenesis. METHODS: Colon cancer was induced in mice with intestine-specific disruption of Ppara (PparaΔIE), Pparafl/fl (control), and mice with disruption of Ppara that express human PPARA (human PPARA transgenic mice), by administration of azoxymethane with or without dextran sulfate sodium (DSS). Colons were collected from mice and analyzed by immunoblots, quantitative polymerase chain reaction, and histopathology. Liquid chromatography coupled with mass spectrometry-based metabolomic analyses were performed on urine and colons. We used molecular biology and biochemical approaches to study mechanisms in mouse colons, primary intestinal epithelial cells, and colon cancer cell lines. Gene expression data and clinical features of patients with colorectal tumors were obtained from Oncomine, and human colorectal-tumor specimens and adjacent normal tissues were collected and analyzed by immunohistochemistry. RESULTS: Levels of Ppara messenger RNA were reduced in colon tumors from mice. PparaΔIE mice developed more and larger colon tumors than control mice following administration of azoxymethane, with or without DSS. Metabolomic analyses revealed increases in methylation-related metabolites in urine and colons from PparaΔIE mice, compared with control mice, following administration of azoxymethane, with or without DSS. Levels of DNA methyltransferase 1 (DNMT1) and protein arginine methyltransferase 6 (PRMT6) were increased in colon tumors from PparaΔIE mice, compared with colon tumors from control mice. Depletion of PPARα reduced the expression of retinoblastoma protein, resulting in increased expression of DNMT1 and PRMT6. DNMT1 and PRMT6 decreased expression of the tumor suppressor genes Cdkn1a (P21) and Cdkn1b (p27) via DNA methylation and histone H3R2 dimethylation-mediated repression of transcription, respectively. Fenofibrate protected human PPARA transgenic mice from azoxymethane and DSS-induced colon cancer. Human colon adenocarcinoma specimens had lower levels of PPARA and retinoblastoma protein and higher levels of DNMT1 and PRMT6 than normal colon tissues. CONCLUSIONS: Loss of PPARα from the intestine promotes colon carcinogenesis by increasing DNMT1-mediated methylation of P21 and PRMT6-mediated methylation of p27 in mice. Human colorectal tumors have lower levels of PPARA messenger RNA and protein than nontumor tissues. Agents that activate PPARα might be developed for chemoprevention or treatment of colon cancer.


Assuntos
Adenocarcinoma/prevenção & controle , Colo/enzimologia , Neoplasias do Colo/prevenção & controle , DNA (Citosina-5-)-Metiltransferase 1/metabolismo , Metilação de DNA , Proteínas Nucleares/metabolismo , PPAR alfa/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Adenocarcinoma/enzimologia , Adenocarcinoma/genética , Adenocarcinoma/patologia , Animais , Anticarcinógenos/farmacologia , Estudos de Casos e Controles , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Colo/patologia , Neoplasias do Colo/enzimologia , Neoplasias do Colo/genética , Neoplasias do Colo/patologia , DNA (Citosina-5-)-Metiltransferase 1/genética , Metilação de DNA/efeitos dos fármacos , Bases de Dados Genéticas , Modelos Animais de Doenças , Fenofibrato/farmacologia , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Nucleares/genética , PPAR alfa/agonistas , PPAR alfa/deficiência , PPAR alfa/genética , Proteína-Arginina N-Metiltransferases/genética , Transdução de Sinais
12.
Cell Mol Life Sci ; 76(15): 2871-2872, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31177294

RESUMO

Protein post-translational modifications (PTMs) have long been a topic of intensive investigation. Covalent additions to the 20 genetically encoded amino acids can alter protein interactions and can even change enzymatic function. In eukarya, PTMs can amplify both the complexity and functional paradigms of the cellular environment. Therefore, PTMs have been of substantial research interest, both for understanding fundamental mechanisms and to provide insight into drug design. Indeed, targeting proteins involved in writing, reading, and erasing PTMs important for human pathologies are some of the most fruitful avenues of drug discovery. In this multi-author review, we explore exciting new work on lysine and arginine methylation, molecular and structural understanding of some of the lysine and arginine methyltransferases (KMTs and PRMTs, respectively), novel insights into nucleic acid methylation, and how the enzymes responsible for writing these PTMs and readers responsible for recognizing these PTMs could be drugged. Here, we introduce the background and the topics covered in this issue.


Assuntos
Processamento de Proteína Pós-Traducional , Arginina/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Histonas/metabolismo , Humanos , Lisina/metabolismo , Metilação , Proteína-Arginina N-Metiltransferases/metabolismo
13.
Nat Commun ; 10(1): 2669, 2019 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-31209209

RESUMO

The Mediator complex regulates transcription by connecting enhancers to promoters. High Mediator binding density defines super enhancers, which regulate cell-identity genes and oncogenes. Protein interactions of Mediator may explain its role in these processes but have not been identified comprehensively. Here, we purify Mediator from neural stem cells (NSCs) and identify 75 protein-protein interaction partners. We identify super enhancers in NSCs and show that Mediator-interacting chromatin modifiers colocalize with Mediator at enhancers and super enhancers. Transcription factor families with high affinity for Mediator dominate enhancers and super enhancers and can explain genome-wide Mediator localization. We identify E-box transcription factor Tcf4 as a key regulator of NSCs. Tcf4 interacts with Mediator, colocalizes with Mediator at super enhancers and regulates neurogenic transcription factor genes with super enhancers and broad H3K4me3 domains. Our data suggest that high binding-affinity for Mediator is an important organizing feature in the transcriptional network that determines NSC identity.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento/fisiologia , Redes Reguladoras de Genes/fisiologia , Complexo Mediador/metabolismo , Células-Tronco Neurais/fisiologia , Neurogênese/genética , Fator de Transcrição 4/metabolismo , Linhagem Celular , Elementos Facilitadores Genéticos/genética , Histonas/metabolismo , Humanos , Histona Desmetilases com o Domínio Jumonji/metabolismo , Oxirredutases N-Desmetilantes/metabolismo , Regiões Promotoras Genéticas/genética , Mapeamento de Interação de Proteínas , Mapas de Interação de Proteínas/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Transcrição Genética/fisiologia
14.
Blood ; 134(6): 548-560, 2019 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-31217189

RESUMO

The presence of FMS-like receptor tyrosine kinase-3 internal tandem duplication (FLT3-ITD) mutations in patients with acute myeloid leukemia (AML) is associated with poor clinical outcome. FLT3 tyrosine kinase inhibitors (TKIs), although effective in kinase ablation, do not eliminate primitive FLT3-ITD+ leukemia cells, which are potential sources of relapse. Thus, understanding the mechanisms underlying FLT3-ITD+ AML cell persistence is essential to devise future AML therapies. Here, we show that expression of protein arginine methyltransferase 1 (PRMT1), the primary type I arginine methyltransferase, is increased significantly in AML cells relative to normal hematopoietic cells. Genome-wide analysis, coimmunoprecipitation assay, and PRMT1-knockout mouse studies indicate that PRMT1 preferentially cooperates with FLT3-ITD, contributing to AML maintenance. Genetic or pharmacological inhibition of PRMT1 markedly blocked FLT3-ITD+ AML cell maintenance. Mechanistically, PRMT1 catalyzed FLT3-ITD protein methylation at arginine 972/973, and PRMT1 promoted leukemia cell growth in an FLT3 methylation-dependent manner. Moreover, the effects of FLT3-ITD methylation in AML cells were partially due to cross talk with FLT3-ITD phosphorylation at tyrosine 969. Importantly, FLT3 methylation persisted in FLT3-ITD+ AML cells following kinase inhibition, indicating that methylation occurs independently of kinase activity. Finally, in patient-derived xenograft and murine AML models, combined administration of AC220 with a type I PRMT inhibitor (MS023) enhanced elimination of FLT3-ITD+ AML cells relative to AC220 treatment alone. Our study demonstrates that PRMT1-mediated FLT3 methylation promotes AML maintenance and suggests that combining PRMT1 inhibition with FLT3 TKI treatment could be a promising approach to eliminate FLT3-ITD+ AML cells.


Assuntos
Arginina/metabolismo , Duplicação Gênica , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Proteínas Repressoras/metabolismo , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , Animais , Biomarcadores Tumorais , Catálise , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Humanos , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/patologia , Metilação , Camundongos , Camundongos Knockout , Modelos Moleculares , Prognóstico , Ligação Proteica , Conformação Proteica , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/química , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/química , Ensaios Antitumorais Modelo de Xenoenxerto , Tirosina Quinase 3 Semelhante a fms/química
15.
Int J Mol Sci ; 20(9)2019 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052191

RESUMO

Tubulins and microtubules (MTs) represent targets for taxane-based chemotherapy. To date, several lines of evidence suggest that effectiveness of compounds binding tubulin often relies on different post-translational modifications on tubulins. Among them, methylation was recently associated to drug resistance mechanisms impairing taxanes binding. The sea urchin is recognized as a research model in several fields including fertilization, embryo development and toxicology. To date, some α- and ß-tubulin genes have been identified in P. lividus, while no data are available in echinoderms for arginine methyl transferases (PRMT). To evaluate the exploiting of the sea urchin embryo in the field of antiproliferative drug development, we carried out a survey of the expressed α- and ß-tubulin gene sets, together with a comprehensive analysis of the PRMT gene family and of the methylable arginine residues in P. lividus tubulins. Because of their specificities, the sea urchin embryo may represent an interesting tool for dissecting mechanisms of tubulin targeting drug action. Therefore, results herein reported provide evidences supporting the P. lividus embryo as animal system for testing antiproliferative drugs.


Assuntos
Citostáticos/toxicidade , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Ouriços-do-Mar/efeitos dos fármacos , Testes de Toxicidade/métodos , Moduladores de Tubulina/toxicidade , Tubulina (Proteína)/metabolismo , Animais , Embrião não Mamífero/efeitos dos fármacos , Metilação , Processamento de Proteína Pós-Traducional , Ouriços-do-Mar/embriologia
16.
J Insect Physiol ; 116: 57-69, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31039373

RESUMO

Neural development depends on the controlled proliferation and differentiation of neural precursors. In holometabolous insects, these processes must be coordinated during larval and pupal development. Recently, protein arginine methylation has come into focus as an important mechanism of controlling neural stem cell proliferation and differentiation in mammals. Whether a similar mechanism is at work in insects is unknown. We investigated this possibility by determining the expression pattern of three protein arginine methyltransferase mRNAs (PRMT1, 4 and 5) in the developing brain of bumblebees by in situ hybridisation. We detected expression in neural precursors and neurons in functionally important brain areas throughout development. We found markedly higher expression of PRMT1, but not PRMT4 and PRMT5, in regions of mushroom bodies containing dividing cells during pupal stages at the time of active neurogenesis within this brain area. At later stages of development, PRMT1 expression levels were found to be uniform and did not correlate with actively dividing cells. Our study suggests a role for PRMT1 in regulating neural precursor divisions in the mushroom bodies of bumblebees during the period of neurogenesis.


Assuntos
Abelhas/genética , Expressão Gênica , Proteínas de Insetos/genética , Corpos Pedunculados/crescimento & desenvolvimento , Neurogênese/fisiologia , Proteína-Arginina N-Metiltransferases/genética , Animais , Abelhas/crescimento & desenvolvimento , Abelhas/metabolismo , Encéfalo/crescimento & desenvolvimento , Proteínas de Insetos/metabolismo , Larva/genética , Larva/crescimento & desenvolvimento , Larva/metabolismo , Proteína-Arginina N-Metiltransferases/metabolismo , Pupa/genética , Pupa/crescimento & desenvolvimento , Pupa/metabolismo , RNA Mensageiro/metabolismo , Fatores de Tempo
17.
Parasit Vectors ; 12(1): 221, 2019 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-31068219

RESUMO

BACKGROUND: Protein arginine methylation is a prevalent post-translational modification. The protein arginine methyltransferase family (PRMT) is involved in many cellular processes in eukaryotes, including transcriptional regulation, epigenetic regulation, RNA metabolism, and DNA damage repair. Toxoplasma gondii, an opportunistic protozoan parasite, encodes five conserved PRMTs. PRMT5 is thought to be responsible for substantial PRMT activity in T. gondii; however, it has not yet been characterized. METHODS: We tagged the 3' end of the endogenous TgPRMT5 genomic locus with sequence encoding a 3X hemagglutinin (HA) epitope. IFA and WB were performed to check the expression and subcellular localization of TgPRMT5 in tachyzoites and bradyzoites. In vitro methylation assays were performed to determine whether endogenous TgPRMT5 has arginine methyltransferase activity. RESULTS: IFA and WB results showed that T. gondii PRMT5 (TgPRMT5) was localized in the cytoplasm in the tachyzoite stage; however, it shifts largely to the nuclear compartment in the bradyzoite stage. The in vitro methylation showed that TgPRMT5 has authentic type II PRMT activity and forms monomethylarginines and symmetric dimethylarginines. CONCLUSIONS: We determined the expression and cellular localization of TgPRMT5 in tachyzoites and bradyzoites and confirmed its type II PRMT activity. We demonstrated the major changes in expression and cellular localization of TgPRMT5 during the tachyzoite and bradyzoite stages in T. gondii. Our findings suggest that TgPRMT5 protein may be involved in tachyzoite-bradyzoite transformation.


Assuntos
Proteína-Arginina N-Metiltransferases/genética , Toxoplasma/enzimologia , Toxoplasma/genética , Citoplasma/química , Epigênese Genética , Estágios do Ciclo de Vida , Metilação , Proteína-Arginina N-Metiltransferases/metabolismo
18.
Hum Cell ; 32(3): 390-396, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31079326

RESUMO

Dysregulation of microRNAs (miRNAs) is frequently found in the tumorigenesis of osteosarcoma (OS). miR-376a was found to play tumor suppressive roles in human cancers. However, the role of miR-376a in OS remains unclear. The expression of miR-376a was analyzed by quantitative real-time PCR (qRT-PCR) in OS cell lines. Cell proliferation assay, cell invasion assay, and cell apoptosis assay were performed to detect the biological function of miR-376a after synthetic miRNA transfection. The target of miR-376a was predicted by TargetScan and miRDB, and further validated by luciferase activity reporter assay and western blot. miR-376a expression was revealed to be decreased in OS cell lines. In vitro experiments showed that overexpression of miR-376a inhibits OS cell proliferation and invasion but promotes apoptosis. Luciferase activity reporter assay and western blot assay showed F-box protein 11 (FBXO11) was a direct target of miR-376a. Furthermore, FBXO11 mediated the role of miR-376a on the proliferation, invasion, and apoptosis of OS cells. Collectively, these results revealed miR-376a functions as a tumor suppressor by targeting FBXO11 in OS. It may be developed as a therapeutic target for OS patients.


Assuntos
Proliferação de Células/genética , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , Expressão Gênica , Genes Supressores de Tumor , MicroRNAs/genética , MicroRNAs/metabolismo , Osteossarcoma/genética , Osteossarcoma/patologia , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Apoptose/genética , Células Cultivadas , Humanos , MicroRNAs/fisiologia , Terapia de Alvo Molecular , Invasividade Neoplásica/genética , Osteossarcoma/terapia
19.
Cell Mol Life Sci ; 76(15): 2917-2932, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31123777

RESUMO

Protein arginine methyltransferases (PRMTs) catalyze the methyl transfer to the arginine residues of protein substrates and are classified into three major types based on the final form of the methylated arginine. Recent studies have shown a strong correlation between PRMT expression level and the prognosis of cancer patients. Currently, crystal structures of eight PRMT members have been determined. Kinetic and structural studies have shown that all PRMTs share similar, but unique catalytic and substrate recognition mechanism. In this review, we discuss the structural similarities and differences of different PRMT members, focusing on their overall structure, S-adenosyl-L-methionine-binding pocket, substrate arginine recognition and catalytic mechanisms. Since PRMTs are valuable targets for drug discovery, we also rationally classify the known PRMT inhibitors into five classes and discuss their mechanisms of action at the atomic level.


Assuntos
Proteína-Arginina N-Metiltransferases/metabolismo , Arginina/metabolismo , Sítios de Ligação , Domínio Catalítico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Humanos , Metilação , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/metabolismo , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Especificidade por Substrato
20.
Cell Mol Life Sci ; 76(15): 2967-2985, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31104094

RESUMO

The methylation of proteins is integral to the execution of many important biological functions, including cell signalling and transcriptional regulation. Protein methyltransferases (PMTs) are a large class of enzymes that carry out the addition of methyl marks to a broad range of substrates. PMTs are critical for normal cellular physiology and their dysregulation is frequently observed in human disease. As such, PMTs have emerged as promising therapeutic targets with several inhibitors now in clinical trials for oncology indications. The discovery of chemical inhibitors and antagonists of protein methylation signalling has also profoundly impacted our general understanding of PMT biology and pharmacology. In this review, we present general principles for drugging protein methyltransferases or their downstream effectors containing methyl-binding modules, as well as best-in-class examples of the compounds discovered and their impact both at the bench and in the clinic.


Assuntos
Histona-Lisina N-Metiltransferase/metabolismo , Medicina de Precisão , Regulação Alostérica , Sítios de Ligação , Domínio Catalítico , Inibidores Enzimáticos/química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/uso terapêutico , Histona-Lisina N-Metiltransferase/antagonistas & inibidores , Histona-Lisina N-Metiltransferase/classificação , Humanos , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Neoplasias/patologia , Processamento de Proteína Pós-Traducional , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Proteína-Arginina N-Metiltransferases/classificação , Proteína-Arginina N-Metiltransferases/metabolismo
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