Humans ; Cardiovascular Diseases ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Histones ; Methyltransferases

Humans ; Cardiovascular Diseases ; Enhancer of Zeste Homolog 2 Protein/metabolism* ; Histones ; Methyltransferases

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*

Animals ; Carrier Proteins/metabolism* ; Histidine/metabolism* ; Humans ; Methylation ; Methyltransferases/metabolism* ; Neoplasm Proteins/metabolism* ; Neoplasms/metabolism* ; Protein Processing, Post-Translational

Protein lysine methylation is a prevalent post-translational modification (PTM) and plays critical roles in all domains of life. However, its extent and function in photosynthetic organisms are still largely unknown. Cyanobacteria are a large group of prokaryotes that carry out oxygenic photosynthesis and are applied extensively in studies of photosynthetic mechanisms and environmental adaptation. Here we integrated propionylation of monomethylated proteins, enrichment of the modified peptides, and mass spectrometry (MS) analysis to identify monomethylated proteins in Synechocystis sp. PCC 6803 (Synechocystis). Overall, we identified 376 monomethylation sites in 270 proteins, with numerous monomethylated proteins participating in photosynthesis and carbon metabolism. We subsequently demonstrated that CpcM, a previously identified asparagine methyltransferase in Synechocystis, could catalyze lysine monomethylation of the potential aspartate aminotransferase Sll0480 both in vivo and in vitro and regulate the enzyme activity of Sll0480. The loss of CpcM led to decreases in the maximum quantum yield in primary photosystem II (PSII) and the efficiency of energy transfer during the photosynthetic reaction in Synechocystis. We report the first lysine monomethylome in a photosynthetic organism and present a critical database for functional analyses of monomethylation in cyanobacteria. The large number of monomethylated proteins and the identification of CpcM as the lysine methyltransferase in cyanobacteria suggest that reversible methylation may influence the metabolic process and photosynthesis in both cyanobacteria and plants.
Bacterial Proteins/metabolism* ; Lysine/metabolism* ; Methyltransferases/metabolism* ; Photosynthesis ; Protein Processing, Post-Translational ; Synechocystis/growth & development*

N-methyladenosine (mA), catalyzed by the methyltransferase complex consisting of Mettl3 and Mettl14, is the most abundant RNA modification in mRNAs and participates in diverse biological processes. However, the roles and precise mechanisms of mA modification in regulating neuronal development and adult neurogenesis remain unclear. Here, we examined the function of Mettl3, the key component of the complex, in neuronal development and adult neurogenesis of mice. We found that the depletion of Mettl3 significantly reduced mA levels in adult neural stem cells (aNSCs) and inhibited the proliferation of aNSCs. Mettl3 depletion not only inhibited neuronal development and skewed the differentiation of aNSCs more toward glial lineage, but also affected the morphological maturation of newborn neurons in the adult brain. mA immunoprecipitation combined with deep sequencing (MeRIP-seq) revealed that mA was predominantly enriched in transcripts related to neurogenesis and neuronal development. Mechanistically, mA was present on the transcripts of histone methyltransferase Ezh2, and its reduction upon Mettl3 knockdown decreased both Ezh2 protein expression and consequent H3K27me3 levels. The defects of neurogenesis and neuronal development induced by Mettl3 depletion could be rescued by Ezh2 overexpression. Collectively, our results uncover a crosstalk between RNA and histone modifications and indicate that Mettl3-mediated mA modification plays an important role in regulating neurogenesis and neuronal development through modulating Ezh2.
Adenosine ; analogs & derivatives ; metabolism ; Adult Stem Cells ; cytology ; metabolism ; Animals ; Brain ; metabolism ; Cell Differentiation ; genetics ; Cell Proliferation ; Enhancer of Zeste Homolog 2 Protein ; metabolism ; Gene Expression Regulation ; Methyltransferases ; metabolism ; Mice, Inbred C57BL ; Neural Stem Cells ; cytology ; metabolism ; Neurogenesis ; genetics ; Neurons ; cytology ; metabolism ; RNA, Messenger ; genetics ; metabolism

BACKGROUNDProtein arginine methyltransferases 1 (PRMT1) is over-expressed in a variety of cancers, including lung cancer, and is correlated with a poor prognosis of tumor development. This study aimed to investigate the role of PRMT1 in nonsmall cell lung cancer (NSCLC) migration in vitro.

METHODSIn this study, PRMT1 expression in the NSCLC cell line A549 was silenced using lentiviral vector-mediated short hairpin RNAs. Cell migration was measured using both scratch wound healing and transwell cell migration assays. The mRNA expression levels of matrix metalloproteinase 2 (MMP-2) and tissue inhibitor of metalloproteinase 1, 2 (TIMP1, 2) were measured using quantitative real-time reverse transcription-polymerase chain reaction. The expression levels of protein markers for epithelial-mesenchymal transition (EMT) (E-cadherin, N-cadherin), focal adhesion kinase (FAK), Src, AKT, and their corresponding phosphorylated states were detected by Western blot.

RESULTSCell migration was significantly inhibited in the PRMT1 silenced group compared to the control group. The mRNA expression of MMP-2 decreased while TIMP1 and TIMP2 increased significantly. E-cadherin mRNA expression also increased while N-cadherin decreased. Only phosphorylated Src levels decreased in the silenced group while FAK or AKT remained unchanged.

CONCLUSIONSPRMT1-small hairpin RNA inhibits the migration abilities of NSCLC A549 cells by inhibiting EMT, extracellular matrix degradation, and Src phosphorylation in vitro.

Blotting, Western ; Carcinoma, Non-Small-Cell Lung ; enzymology ; genetics ; Cell Line ; Cell Movement ; genetics ; physiology ; Epithelial-Mesenchymal Transition ; genetics ; physiology ; Extracellular Matrix Proteins ; metabolism ; Humans ; Protein-Arginine N-Methyltransferases ; genetics ; metabolism ; RNA, Small Interfering ; genetics ; physiology

The aim of the present study was to investigate the regulatory effects of histone methylation modifications on the expression of miR-200c, as well as invasion and migration of gastric carcinoma cells. Gastric carcinoma cell line, MGC-803, were treated by 2.5 μmol/L histone methyltransferase inhibitor, DZNep. The expression of miR-200c was detected by real-time quantitative PCR (qRT-PCR). The epithelial-mesenchymal transition (EMT) indicators (ZEB1/2 and E/N-cadherin), EZH2, EED, SUZ12 and H3K27me3 expressions were detected by Western blot. Cell migration and invasion abilities were detected by Transwell and scratch tests. The result showed that, compared with DMSO (control) group, DZNep significantly increased the expression of miR-200c to about 2.1 times, inhibited ZEB1, ZEB2, and N-cadherin expressions, and activated E-cadherin expression; Also, DZNep decreased the protein expressions of EZH2, EED, SUZ12 and H3K27me3; Moreover, DZNep could inhibit MGC-803 cell invasive and migrative abilities, as well as MMP9 expression. These results suggest DZNep raises miR-200c expression to delay the invasion and migration of gastric carcinoma cells, and the underlying mechanisms involve the regulations of EMT-related proteins and polycomb repressive complex 2.
Adenosine ; analogs & derivatives ; pharmacology ; Cadherins ; metabolism ; Cell Line, Tumor ; drug effects ; Cell Movement ; drug effects ; Epithelial-Mesenchymal Transition ; Gene Expression Regulation, Neoplastic ; Homeodomain Proteins ; metabolism ; Humans ; MicroRNAs ; metabolism ; Protein Methyltransferases ; antagonists & inhibitors ; Repressor Proteins ; metabolism ; Transcription Factors ; metabolism ; Zinc Finger E-box Binding Homeobox 2 ; Zinc Finger E-box-Binding Homeobox 1

Glucose homeostasis is tightly controlled by the regulation of glucose production in the liver and glucose uptake into peripheral tissues, such as skeletal muscle and adipose tissue. Under prolonged fasting, hepatic gluconeogenesis is mainly responsible for glucose production in the liver, which is essential for tissues, organs, and cells, such as skeletal muscle, the brain, and red blood cells. Hepatic gluconeogenesis is controlled in part by the concerted actions of transcriptional regulators. Fasting signals are relayed by various intracellular enzymes, such as kinases, phosphatases, acetyltransferases, and deacetylases, which affect the transcriptional activity of transcription factors and transcriptional coactivators for gluconeogenic genes. Protein arginine methyltransferases (PRMTs) were recently added to the list of enzymes that are critical for regulating transcription in hepatic gluconeogenesis. In this review, we briefly discuss general aspects of PRMTs in the control of transcription. More specifically, we summarize the roles of four PRMTs: PRMT1, PRMT 4, PRMT 5, and PRMT 6, in the control of hepatic gluconeogenesis through specific regulation of FoxO1- and CREB-dependent transcriptional events.
Acetyltransferases ; Adipose Tissue ; Arginine* ; Brain ; Erythrocytes ; Fasting ; Gluconeogenesis ; Glucose* ; Homeostasis ; Liver ; Metabolism* ; Methyltransferases* ; Muscle, Skeletal ; Phosphoric Monoester Hydrolases ; Phosphotransferases ; Protein-Arginine N-Methyltransferases ; Transcription Factors

OBJECTIVETo discuss the effect of matrine on nitric oxide (NO) and asymmetric methylarginine (ADMA) metabolism pathways in serum and tissues of mice with lipopolysaccharide (LPS) -induced intestine tissue inflammation.

METHODKunming mice were randomly divided into five groups: the normal control group, the LPS group and matrine (80, 40, 20 mg x kg(-1) x d(-1)) groups. The mice were intragastrically administered with drugs for 3 d (distilled water of the same volume for the normal control group and the LPS group). One hour after the last intragastrical administration, normal saline or LPS (1 mg x kg(-1)) were intraperitoneally injected. Twelve hours later, serum and tissues were collected to determine NO and ADMA levels and observe the pathological changes of intestinal tissues. The Western blot method was adopted to detect the protein expressions of arginine methyltransferases 1 (PRMT1) and dimethylarginine dimethylaminohydrolase 2 (DDAH2) in intestinal tissues.

RESULTCompared with the model group, matrine (80, 40, 20 mg x kg(-1) x d(-1)) groups showed lower NO content in serum and tissues, higher ADMA level in serum and increased PRMT1 expression in intestinal tissues, but without effect on DDAH2 expression.

CONCLUSIONMatrine could inhibit LPS-induced intestine tissue inflammation in mice. Its action mechanism is related to the decreased NO content in serum and tissues and increased ADMA level in serum and PRMT1 expression in intestinal tissues.

Alkaloids ; administration & dosage ; Animals ; Arginine ; analogs & derivatives ; blood ; metabolism ; Humans ; Inflammation ; Intestinal Diseases ; drug therapy ; enzymology ; immunology ; metabolism ; Intestines ; drug effects ; enzymology ; immunology ; metabolism ; Lipopolysaccharides ; adverse effects ; Male ; Mice ; Nitric Oxide ; blood ; metabolism ; Protein-Arginine N-Methyltransferases ; genetics ; metabolism ; Quinolizines ; administration & dosage