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*

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

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

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

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

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*

C-Terminal carboxyl methylation of a human placental 23 kDa protein catalyzed by membrane-associated methyltransferase has been investigated. The 23 kDa protein substrate methylated was partially purified by DEAE-Sephacel, hydroxyapatite and Sephadex G-100 gel filtration chromatographies. The substrate protein was eluted on Sephadex G-100 gel filtration chromatography as a protein of about 29 kDa. In the absence of Mg2+, the methylation was stimulated by guanine nucleotides (GTP, GDP and GTPgammaS), but in the presence of Mg2+, only GTPgammaS stimulated the methylation which was similar to the effect on the G25K/rhoGDI complex. AFC, an inhibitor of C-terminal carboxyl methylation, inhibited the methylation of human placental 23 kDa protein. These results suggests that the substrate is a small G protein different from the G25K and is methylated on C-terminal isoprenylated cysteine residue. This was also confirmed by vapor phase analysis. The methylated substrate protein was redistributed to membrane after in vitro methylation, suggesting that the methylation of this protein is important for the redistribution of the 23 kDa small G protein for its putative role in intracellular signaling.
Cysteine/metabolism* ; Female ; GTP-Binding Proteins/metabolism* ; Guanine Nucleotides/pharmacology ; Human ; Methylation ; Placenta/metabolism* ; Placenta/enzymology ; Pregnancy ; Pregnancy Proteins/metabolism* ; Protein Methyltransferases/metabolism*

OBJECTIVETo observe the expression of protein arginine N-methyltransferase (PRMT) genes in the lung and spleen of E3 rats with acute asthma.

METHODSE3 rats with ovalbumin-induced pulmonary inflammation were divided into two groups (n=10), and the validity of the acute asthma model was evaluated by histological observation with HE and PAS staining and by measurement of NO production. Semi-quantitative RT-PCR was employed to detect the expressions of PRMT1-PRMT6 genes in the lung and spleen tissues of the rats.

RESULTSIn the lung tissue of the asthmatic rats, the gene expressions of PRMT1 (P<0.01), PRMT2 (P<0.01), PRMT3 (P<0.05) and PRMT5 (P<0.05) were significantly increased, but the expression of PRMT4 gene (P<0.05) was significantly decreased as compared with those in the control tissue. In the spleen tissue of the asthmatic rats, the expressions of PRMT2 (P<0.05) and PRMT5 genes (P<0.05) showed a significant increase as compared with those in the control rat tissue.

CONCLUSIONThe gene expressions of PRMTs vary significantly between asthmatic rats and control rats, suggesting that PRMTs play an important role in the post-translational modification process of asthma-related genes.

Acute Disease ; Animals ; Asthma ; enzymology ; Female ; Male ; Protein Processing, Post-Translational ; Protein-Arginine N-Methyltransferases ; classification ; genetics ; metabolism ; Random Allocation ; Rats ; Rats, Inbred Strains

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21(Cip/WAF1) activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21(Cip/WAF1) short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.
Animals ; Arginine ; Cell Dedifferentiation ; Cyclin-Dependent Kinase Inhibitor p21/genetics/metabolism ; Elongation Factor 2 Kinase/*metabolism ; Fibroblast Growth Factor 2/*metabolism ; Fibroblasts/*metabolism/pathology ; Flavonoids/pharmacology ; MAP Kinase Signaling System/drug effects/genetics ; Methylation ; Mice ; Mitogen-Activated Protein Kinases/antagonists & inhibitors ; Myofibroblasts/pathology ; NIH 3T3 Cells ; Protein Methyltransferases/*metabolism ; Protein-Arginine N-Methyltransferases/*metabolism ; RNA, Small Interfering/genetics

Protein arginine methylation is important for a variety of cellular processes including transcriptional regulation, mRNA splicing, DNA repair, nuclear/cytoplasmic shuttling and various signal transduction pathways. However, the role of arginine methylation in protein biosynthesis and the extracellular signals that control arginine methylation are not fully understood. Basic fibroblast growth factor (bFGF) has been identified as a potent stimulator of myofibroblast dedifferentiation into fibroblasts. We demonstrated that symmetric arginine dimethylation of eukaryotic elongation factor 2 (eEF2) is induced by bFGF without the change in the expression level of eEF2 in mouse embryo fibroblast NIH3T3 cells. The eEF2 methylation is preceded by ras-raf-mitogen-activated protein kinase kinase (MEK)-extracellular signal-regulated kinase (ERK1/2)-p21(Cip/WAF1) activation, and suppressed by the mitogen-activated protein kinase (MAPK) inhibitor PD98059 and p21(Cip/WAF1) short interfering RNA (siRNA). We determined that protein arginine methyltransferase 7 (PRMT7) is responsible for the methylation, and that PRMT5 acts as a coordinator. Collectively, we demonstrated that eEF2, a key factor involved in protein translational elongation is symmetrically arginine-methylated in a reversible manner, being regulated by bFGF through MAPK signaling pathway.
Animals ; Arginine ; Cell Dedifferentiation ; Cyclin-Dependent Kinase Inhibitor p21/genetics/metabolism ; Elongation Factor 2 Kinase/*metabolism ; Fibroblast Growth Factor 2/*metabolism ; Fibroblasts/*metabolism/pathology ; Flavonoids/pharmacology ; MAP Kinase Signaling System/drug effects/genetics ; Methylation ; Mice ; Mitogen-Activated Protein Kinases/antagonists & inhibitors ; Myofibroblasts/pathology ; NIH 3T3 Cells ; Protein Methyltransferases/*metabolism ; Protein-Arginine N-Methyltransferases/*metabolism ; RNA, Small Interfering/genetics