METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on stemness maintenance of mouse embryonic stem cell (mESC). While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-independent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification. Mechanistically, METTL14, but not METTL3, binds H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression. The effects of METTL14 on regulation of H3K27me3 is essential for the transition from self-renewal to differentiation of mESCs. This work reveals a regulatory mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance, and differentiation of mESCs.
Animals ; Mice ; Methylation ; Chromatin ; Histones/metabolism* ; RNA, Messenger/genetics* ; Methyltransferases/metabolism* ; RNA/metabolism*

The histone methyltransferase enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2)-mediated trimethylation of histone H3 lysine 27 (H3K27me3) regulates neural stem cell proliferation and fate specificity through silencing different gene sets in the central nervous system. Here, we explored the function of EZH2 in early post-mitotic neurons by generating a neuron-specific Ezh2 conditional knockout mouse line. The results showed that a lack of neuronal EZH2 led to delayed neuronal migration, more complex dendritic arborization, and increased dendritic spine density. Transcriptome analysis revealed that neuronal EZH2-regulated genes are related to neuronal morphogenesis. In particular, the gene encoding p21-activated kinase 3 (Pak3) was identified as a target gene suppressed by EZH2 and H3K27me3, and expression of the dominant negative Pak3 reversed Ezh2 knockout-induced higher dendritic spine density. Finally, the lack of neuronal EZH2 resulted in impaired memory behaviors in adult mice. Our results demonstrated that neuronal EZH2 acts to control multiple steps of neuronal morphogenesis during development, and has long-lasting effects on cognitive function in adult mice.
Animals ; Mice ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Histone Methyltransferases/metabolism* ; Histones/genetics* ; Morphogenesis ; Neuronal Plasticity ; Neurons/metabolism*

Thiopurine S-methyltransferase (TPMT) methylates purine analogues, showing TPMT activity in inverse relation to concentrations of active metabolites such as 6-thioguanine nucleotide (6-TGN). With conventional dosing of thiopurines, patients with homozygous variant TPMT alleles consistently suffer from severe myelosuppression. Here, we report a patient with TPMT*3C/*3C who managed successfully with monitoring of thiopurine metabolites. The patient was an 18-year-old male diagnosed with Crohn's disease. The standard dose of azathioprine (AZA) (1.8 mg/kg/day) with mesalazine (55.6 mg/kg/day) was prescribed. Two weeks after starting AZA treatment, the patient developed leukopenia. The DNA sequence analysis of TPMT identified a homozygous missense variation (NM_000367.2: c.719A>G; p.Tyr240Cys), TPMT*3C/*3C. He was treated with adjusted doses of azathioprine (0.1-0.2 mg/kg/day) and his metabolites were closely monitored. Leukopenia did not reoccur during the follow-up period of 24 months. To our knowledge, this is the first case of a patient homozygous for TPMT*3C successfully treated with azathioprine in Korea. While a TPMT genotyping test may be helpful to determine a safe starting dose, it may not completely prevent myelosuppression. Monitoring metabolites as well as routine laboratory tests can contribute to assessing drug metabolism and optimizing drug dosing with minimized drug-induced toxicity.
Adolescent ; Azathioprine/adverse effects/*therapeutic use ; Homozygote ; Humans ; Inflammatory Bowel Diseases/*drug therapy/*enzymology/*genetics/metabolism ; Male ; Methyltransferases/*genetics

OBJECTIVE: To examine the expression of DNMT1, DNMT3a, and DNMT3b in the eutopic and ectopic endometrium in women with endometriosis. METHODS: RT-PCR and real-time RT-PCR were used to examine the expression of DNMT1, DNMT3a, and DNMT3b in the eutopic and ectopic endometrium in 20 women with endometriosis and the endometrium in 20 women without endometriosis. Immunofluorescene staining was used to detect the expression of DNMT1 in these tissues. RESULTS: The expression levels of DNMT1, DNMT3a, and DNMT3b were significantly lower in the ectopic endometrium and eutopic endometrium than those of the control endometium (P<0.05). The changes in the ectopic endometium compared with the control endometium were 0.44, 0.12, and 0.27 folds for DNMT1, DNMT3a, and DNMT3b, respectively, and these in the eutopic endometrium were 0.27, 0.13, and 0.15 folds for DNMT1,DNMT3a, and DNMT3b, respectively. The expression level of DNMT1, DNMT3a, and DNMT3b between the ectopic endometrium and eutopic endometrium was not significantly different (P>0.05 ). Immunofluorescence staining that DNMT1 protein level significantly decreased in the ectopic endometrium and eutopic endometrium of endometriosis patients. CONCLUSION Decreased expression levels of DNMT1, DNMT3a, and DNMT3b in the ectopic endometrium and eutopic endometrium may play a role in patients with abnormal epigenetics which may lead to endometriosis.
Adult ; DNA (Cytosine-5-)-Methyltransferase 1 ; DNA (Cytosine-5-)-Methyltransferases ; metabolism ; Endometriosis ; enzymology ; genetics ; Endometrium ; enzymology ; Epigenomics ; Female ; Humans

Arabidopsis AtPRMT10 is a plant-specific type I protein arginine methyltransferase that can asymmetrically dimethylate arginine 3 of histone H4 with auto-methylation activity. Mutations of AtPRMT10 derepress FLOWERING LOCUS C (FLC) expression resulting in a late-flowering phenotype. Here, to further investigate the biochemical characteristics of AtPRMT10, we analyzed a series of mutated forms of the AtPRMT10 protein. We demonstrate that the conserved "VLD" residues and "double-E loop" are essential for enzymatic activity of AtPRMT10. In addition, we show that Arg54 and Cys259 of AtPRMT10, two residues unreported in animals, are also important for its enzymatic activity. We find that Arg13 of AtPRMT10 is the auto-methylation site. However, substitution of Arg13 to Lys13 does not affect its enzymatic activity. In vivo complementation assays reveal that plants expressing AtPRMT10 with VLD-AAA, E143Q or E152Q mutations retain high levels of FLC expression and fail to rescue the late-flowering phenotype of atprmt10 plants. Taken together, we conclude that the methyltransferase activity of AtPRMT10 is essential for repressing FLC expression and promoting flowering in Arabidopsis.
Arabidopsis ; enzymology ; Arabidopsis Proteins ; biosynthesis ; genetics ; metabolism ; Enzyme Activation ; Flowers ; genetics ; growth & development ; metabolism ; Genetic Loci ; genetics ; MADS Domain Proteins ; biosynthesis ; genetics ; metabolism ; Methyltransferases ; genetics ; metabolism ; Phenotype ; Recombinant Proteins ; genetics ; metabolism ; Time Factors

Mercaptopurine is a common chemotherapeutic drug and immunosuppressive agent and plays an important role in the treatment of acute lymphoblastic leukemia and inflammatory bowel disease. It may cause severe adverse effects such as myelosuppression, which may result in the interruption of treatment or complications including infection or even threaten patients' lives. However, the adverse effects of mercaptopurine show significant racial and individual differences, which reveal the important role of genetic diversity. Recent research advances in pharmacogenomics have gradually revealed the genetic nature of such differences. This article reviews the recent research advances in the pharmacogenomics and individualized application of mercaptopurine.
Antimetabolites, Antineoplastic ; therapeutic use ; Humans ; Mercaptopurine ; metabolism ; therapeutic use ; Methyltransferases ; genetics ; Pharmacogenetics ; Polymorphism, Genetic ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; drug therapy ; genetics ; Pyrophosphatases ; genetics

BACKGROUND: DNA methylation is involved in numerous biologic events and associates with transcriptional gene silencing, playing an important role in the pathogenesis of endometrial cancer. ESR1/PGR frequently undergoes de novo methylation and loss expression in a wide variety of tumors, including breast, colon, lung, and brain tumors. However, the mechanisms underlying estrogen and progesterone receptors (ER/PR) loss in endometrial cancer have not been studied extensively. The aims of this study were to determine the expression of DNA (cytosine-5)-methyltransferase 3A/3B (DNMT3A/3B) in endometrial cancer to investigate whether the methylation catalyzed by DNMT3A/3B contributes to low ER/PR expression. METHODS: The clinicopathologic information and RNA-Seq expression data of DNMT3A/3B of 544 endometrial cancers were derived from The Cancer Genome Atlas (TCGA) uterine cancer cohort in May 2018. RNA-Seq level of DNMT3A/3B was compared between these clinicopathologic factors with t-test or one-way analysis of variance. RESULTS: DNMT3A/3B was overexpressed in endometrioid carcinoma (EEC) and was even higher in non-endometrioid carcinoma (NEEC) (DNMT3A, EEC vs. NEEC: 37.6% vs. 69.9%, t = -7.440, P < 0.001; DNMT3B, EEC vs. NEEC: 42.4% vs. 72.8%, t = -6.897, P < 0.001). In EEC, DNMT3A overexpression was significantly correlated with the hypermethylation and low expression of the ESR1 and PGR (P < 0.05). The same trend was observed in the DNMT3B overexpression subgroup. In the ESR1/PGR low-expression subgroups, as much as 83.1% of ESR1 and 59.5% of PGR were hypermethylated, which was significantly greater than the ESR1/PGR high-expression subgroups (31.3% and 11.9%, respectively). However, the above phenomena were absent in NEEC, while DNMT3A/3B overexpression, ESR1/PGR hypermethylation, and low ER/PR expression occurred much more often. In univariate analysis, DNMT3A/3B overexpressions were significantly correlated with worse prognosis. In multivariate analysis, only DNMT3A was an independent predictor of disease-free survival (P < 0.05). CONCLUSIONS DNMT3A/3B expression increases progressively from EEC to NEEC and is correlated with poor survival. The mechanisms underlying low ER/PR expression might be distinct in EEC vs. NEEC. In EEC, methylation related to DNMT3A/3B overexpression might play a major role in ER/PR downregulation.
Adult ; Aged ; Aged, 80 and over ; Carcinoma, Endometrioid ; genetics ; metabolism ; pathology ; DNA (Cytosine-5-)-Methyltransferases ; genetics ; metabolism ; DNA Methylation ; genetics ; Endometrial Neoplasms ; genetics ; metabolism ; pathology ; Estrogen Receptor alpha ; genetics ; metabolism ; Female ; Gene Expression Regulation, Neoplastic ; Humans ; Immunohistochemistry ; Male ; Middle Aged ; Prognosis

OBJECTIVETo construct the eukaryotic expression plasmid of mouse histone lysine methyltransferase Setd7 and detect its effect on neuron development.

METHODSThe clone of mouse Setd7 was obtained and inserted into the eukaryotic expression vector pCMV-3tag-6-Flag. The plasmid was transfected into HEK 293T and identified by Western blot. Real-time PCR was used to detect the effect of Setd7 on the neuron differentiation marker gene Ngn 1 mRNA expression. Dual luciferase reporter system was used to detect the effect of Setd7 on Ngn 1 mRNA expression. Real-time PCR was used to detect the effect of Setd 7 siRNA plasmid on Ngn 1 mRNA expression.

RESULTSAn eukaryotic expression plasmid of Setd 7 was successfully constructed. Setd7 induced Ngn 1 mRNA expression and increased Ngn 1 promoter activity. Also, the knockdown of Setd 7 inhibited Ngn 1 mRNA expression.

CONCLUSIONHistone lysine methyltransferase Setd7 can enhance neuron differentiation marker gene Ngn 1 transcription.

Animals ; Basic Helix-Loop-Helix Transcription Factors ; genetics ; metabolism ; Gene Expression Regulation ; Genetic Vectors ; HEK293 Cells ; Histone-Lysine N-Methyltransferase ; genetics ; metabolism ; Humans ; Mice ; Nerve Tissue Proteins ; genetics ; metabolism ; Protein Methyltransferases ; genetics ; metabolism ; RNA, Messenger ; genetics ; Transfection

OBJECTIVETo explore the role of BM2 protein in the life cycle of influenza B virus.

METHODSThe authors screened human kidney MATCHMAKER cDNA library for new binding partners of BM2 of influenza B virus by using the yeast two hybrid system with truncated BM2 (26-109 aa) as the bait.

RESULTSSix positive plasmids encoding N-acetylneuraminate pyruvate lyase, angiopoietin 3, zinc finger protein 251, ribosomal protein S20, protein arginine N-methyltransferase 1 variant 1 (PRMT) and transcription factor-like 1 (TCFL1) were obtained.

CONCLUSIONThe results suggest that BM2 may play an important role in the life cycle of influenza B virus.

Angiopoietin-like Proteins ; Angiopoietins ; genetics ; metabolism ; DNA-Binding Proteins ; genetics ; metabolism ; Gene Library ; Humans ; Influenza B virus ; genetics ; metabolism ; Kidney ; metabolism ; Oxo-Acid-Lyases ; genetics ; metabolism ; Plasmids ; genetics ; Protein Binding ; Protein-Arginine N-Methyltransferases ; genetics ; metabolism ; Repressor Proteins ; genetics ; metabolism ; Ribosomal Proteins ; genetics ; metabolism ; Transcription Factors ; genetics ; metabolism ; Two-Hybrid System Techniques ; Viral Proteins ; genetics ; metabolism ; Zinc Fingers ; genetics

The key challenge to generate engineered cells by synthetic biology for producing 7-dehydrocholesterol (7-DHC) in a high titer is the match between functional module and chassis. Our study focused on solving this problem by combining different promoters and yeast chassis to increase 7-DHC production. To optimize the chassis in order to accumulate zymosterol, the substrate for 7-DHC synthesis, we overexpressed truncated HMG-CoA reductase (tHmglp) and squalene epoxidase (Erglp), both are key genes of yeast endogenous zymosterol biosynthetic pathway. In addition, we knocked out C-24 methyl transferase (Erg6p) and C-22 dehydrogenase (Erg5p) to inhibit the conversion of zymosterol to ergosterol. By introducing heterologous C-24 reductase under three promoters with different strengths, namely TDH3p, PGK1p and TDH1p, we constructed functional modules of diverse activities. Nine engineeredcells were generated based on the combination of these three modules and three chassis. The result shows that the engineered cell composed of functional module regulated by TDH3p and chassis SyBE_000956 had the highest 7-DHC production, indicating a better match than others. This study provides evidences for importance of match and empirical support for rational design of subsequent researches.
Cholesterol ; metabolism ; Cytochrome P-450 Enzyme System ; genetics ; Dehydrocholesterols ; metabolism ; Gene Knockout Techniques ; Hydroxymethylglutaryl CoA Reductases ; metabolism ; Industrial Microbiology ; Methyltransferases ; genetics ; Promoter Regions, Genetic ; Saccharomyces cerevisiae ; genetics ; metabolism ; Saccharomyces cerevisiae Proteins ; genetics ; Synthetic Biology