S-adenosylmethionine Synthase Research Articles

Decreasing in Lysine Reflect Lysosomal Dysfunction and Accumulated Phenylalanine which Connected to WMH and CVD and Both of Phenylketonuria and Calcifications where N-Acetylcysteine Prevent Organs Failure

Phenylalanine function stabilized by lysine which found on lysosomal surface, that Phe necessary to regulate the synthesis or secretion of α-amylase, trypsin and lipase, where the Severe acute pancreatitis in a child with phenylketonuria. The phenylketonuria due to decreased lysine followed by lysosomal dysfunction that will be result of deficiency in phenylalanine function that will not form pancreatic enzymes and stomach enzyme and will be accumulated. The Lysosomal dysfunction will be result of accumulation of undigested polymer including inflammation which play important roles in pathophysiology, that reflect reduction in lysine acylation followed by reduction in aminoacyl tRNAs which promote Phe and E coli functions for activating protein and mRNAs synthesis, that will be followed by increasing in TNf-a synthesis (and reduction in VEGF-As ) which activate NK (not beings related to human immune proper function ) which regulated by the undigested polymers in random pathways stimulated by TNf-a functional pathway (activated by NLRP3 inflammasome. Retinoic acid is necessary to promote lysine acylation which regulate aminoacyl-tRNAs production regulated by mitochondrial enzymes, which regulate mRNA production by E coli (regulated by phenylalanine) that necessary to run antioxidant functions and cellular biosynthesis. Lysine acetylation so important to regulates the activity of Escherichia coli Sadenosylmethionine synthase. RNA (produced by E coli) is 2′-O-methylated demonstrated higher stability that can improve immune by promoting anti-inflammatory processes and improve myocardial functions, and adopt heart constriction by activating NR4As pathway. The antihypertensive pathway mechanism is: the Lysine ¬¬>activate ATPase (stimulate retinoic acid “RA” ) ¬¬>Lysine acetylation ¬¬> promote Phe/ hydroxylase ¬¬> followed by ¬>activate Tyr/ hydroxylase ¬>activate dopamine ¬> activate NR4As pathway ¬>GC-beta ¬>activate both of Oxytocin and Nrf2 ¬> Ang2-AT2 and VEGF-A productive functions ¬>heme oxygenase ¬>anti-inflammatory growth and processes. Lysine Methylation has important role in adopt hypertension through activating pervious Antihypertensive pathway mediated by Phe hydroxylase synthesis and Tyr hydroxylase production followed by activating both of dopamine and NR4As pathway. The oxidation of phenylalanyl-tRNA synthetase positively regulates translational quality control, and regulates the initiation of digestive enzyme mRNA translation, where consecutive AAA-lysines is paused for encoding Phe followed by ribosome sliding on homopolymeric A sequence. That lysine activates mitochondria function followed by promoting Phenylalanine and phenylalanine-tRNAs productions by translations within E coli, followed by Phe/ hydroxylase activate Tyr hydroxylase production which activate dopamine synthesis. And positively, Lysine is the most effective amino acid for activating all of ATPase, GTPase, and lysosomes, and E coli functions, where ATPase necessary for activating lysine Phosphorylation for activating lysosome digestion, followed by activating E coli through activating Phe hydroxylase production, while GTPase necessary for activating mitochondrial repairs, which act on pro-inflammation and cholesterol for activating estrogen production and activating the NR4As pathway which activate all of Oxytocin, Nrf2 followed by Ang2-AT2 and VEGF-A production and then followed by activating heme oxygenase and anti-inflammatory growth and processes that prevent LV-hypertrophy, and prevent coronary calcification.

Molecular mechanism of somatic embryogenesis in paeonia ostii ‘Fengdan’ based on transcriptome analysis combined histomorphological observation and metabolite determination

BackgroundTree peony (Paeonia sect. Moutan DC.) is a famous flower native to China with high ornamental, medicinal, and oil value. However, the low regeneration rate of callus is one of the main constraints for the establishment of a genetic transformation system in tree peony. By histomorphological observation, transcriptomic analysis and metabolite determination, we investigated the molecular mechanism of somatic embryogenesis after the establishment of a culture system and the induction of somatic embryo(SE) formation.ResultsWe found that SE formation was successfully induced when cotyledons were used as explants. A total of 3185 differentially expressed genes were screened by comparative transcriptomic analysis of embryogenic callus (EC), SE, and non-embryogenic callus (NEC). Compared to NEC, the auxin synthesis-related genes GH3.6 and PCO2 were up-regulated, whereas cytokinin dehydrogenase (CKX6) and CYP450 family genes were down-regulated in somatic embryogenesis. In SE, the auxin content was significantly higher than the cytokinin content. The methyltransferase-related gene S-adenosylmethionine synthase (SAMS) and the flavonoid biosynthesis-related gene (ANS and F3’5’H) were down-regulated in somatic embryogenesis. The determination of flavonoids showed that rhoifolin and hyperoside had the highest content in SE. The results of transcriptome analysis were consistent with the relative expression of 8 candidate genes by quantitative polymerase chain reaction analysis.ConclusionThe results revealed that auxin and cytokinin may play a key role in ‘Fengdan’ somatic embryogenesis. The genes related to somatic embryogenesis were revealed, which has partly elucidated the molecular mechanism of somatic embryogenesis in ‘Fengdan’.

Formaldehyde regulates S-adenosylmethionine biosynthesis and one-carbon metabolism.

One-carbon metabolism is an essential branch of cellular metabolism that intersects with epigenetic regulation. In this work, we show how formaldehyde (FA), a one-carbon unit derived from both endogenous sources and environmental exposure, regulates one-carbon metabolism by inhibiting the biosynthesis of S-adenosylmethionine (SAM), the major methyl donor in cells. FA reacts with privileged, hyperreactive cysteine sites in the proteome, including Cys120 in S-adenosylmethionine synthase isoform type-1 (MAT1A). FA exposure inhibited MAT1A activity and decreased SAM production with MAT-isoform specificity. A genetic mouse model of chronic FA overload showed a decrease n SAM and in methylation on selected histones and genes. Epigenetic and transcriptional regulation of Mat1a and related genes function as compensatory mechanisms for FA-dependent SAM depletion, revealing a biochemical feedback cycle between FA and SAM one-carbon units.

Proteome insights of citric acid-mediated cadmium toxicity tolerance in Brassica napus L.

Cadmium (Cd) is a toxic substance that is uptake by plants from soils, Cd easily transfers into the food chain. Considering global food security, eco-friendly, cost-effective, and metal detoxification strategies are highly demandable for sustainable food crop production. The purpose of this study was to investigate how citric acid (CA) alleviates or tolerates Cd toxicity in Brassica using a proteome approach. In this study, the global proteome level was significantly altered under Cd toxicity with or without CA supplementation in Brassica. A total of 4947 proteins were identified using the gel-free proteome approach. Out of these, 476 proteins showed differential abundance between the treatment groups, wherein 316 were upregulated and 160 were downregulated. The gene ontology analysis reveals that differentially abundant proteins were involved in different biological processes including energy and carbohydrate metabolism, CO2 assimilation and photosynthesis, signal transduction and protein metabolism, antioxidant defense, heavy metal detoxification, plant development, and cytoskeleton and cell wall structure in Brassica leaves. Interestingly, several candidate proteins such as superoxide dismutase (A0A078GZ68) L-ascorbate peroxidase 3 (A0A078HSG4), glutamine synthetase (A0A078HLB2), glutathione S-transferase DHAR1 (A0A078HPN8), glutamine synthetase (A0A078HLB2), cysteine synthase (A0A078GAD3), S-adenosylmethionine synthase 2 (A0A078JDL6), and thiosulfate/3-mercaptopyruvate sulfur transferase 2 (A0A078H905) were involved in antioxidant defense system and sulfur assimilation-involving Cd-detoxification process in Brassica. These findings provide new proteome insights into CA-mediated Cd-toxicity alleviation in Brassica, which might be useful to oilseed crop breeders for enhancing heavy metal tolerance in Brassica using the breeding program, with sustainable and smart Brassica production in a metal-toxic environment.

The miRNA-mRNA Regulatory Modules of Pinus massoniana Lamb. in Response to Drought Stress.

Masson pine (Pinus massoniana Lamb.) is a major fast-growing woody tree species and pioneer species for afforestation in barren sites in southern China. However, the regulatory mechanism of gene expression in P. massoniana under drought remains unclear. To uncover candidate microRNAs, their expression profiles, and microRNA-mRNA interactions, small RNA-seq was used to investigate the transcriptome from seedling roots under drought and rewatering in P. massoniana. A total of 421 plant microRNAs were identified. Pairwise differential expression analysis between treatment and control groups unveiled 134, 156, and 96 differential expressed microRNAs at three stages. These constitute 248 unique microRNAs, which were subsequently categorized into six clusters based on their expression profiles. Degradome sequencing revealed that these 248 differentially expressed microRNAs targeted 2069 genes. Gene Ontology enrichment analysis suggested that these target genes were related to translational and posttranslational regulation, cell wall modification, and reactive oxygen species scavenging. miRNAs such as miR482, miR398, miR11571, miR396, miR166, miRN88, and miRN74, along with their target genes annotated as F-box/kelch-repeat protein, 60S ribosomal protein, copper-zinc superoxide dismutase, luminal-binding protein, S-adenosylmethionine synthase, and Early Responsive to Dehydration Stress may play critical roles in drought response. This study provides insights into microRNA responsive to drought and rewatering in Masson pine and advances the understanding of drought tolerance mechanisms in Pinus.

Phage T3 overcomes the BREX defense through SAM cleavage and inhibition of SAM synthesis by SAM lyase

Bacteriophage T3 encodes a SAMase that, through cleavage of S-adenosyl methionine (SAM), circumvents the SAM-dependent type I restriction-modification (R-M) defense. We show that SAMase also allows T3 to evade the BREX defense. Although SAM depletion weakly affects BREX methylation, it completely inhibits the defensive function of BREX, suggesting that SAM could be a co-factor for BREX-mediated exclusion of phage DNA, similar to its anti-defense role in type I R-M. The anti-BREX activity of T3 SAMase is mediated not just by enzymatic degradation of SAM but also by direct inhibition of MetK, the host SAM synthase. We present a 2.8Å cryoelectron microscopy (cryo-EM) structure of the eight-subunit T3 SAMase-MetK complex. Structure-guided mutagenesis reveals that this interaction stabilizes T3 SAMase invivo, further stimulating its anti-BREX activity. This work provides insights in the versatility of bacteriophage counterdefense mechanisms and highlights the role of SAM as a co-factor of diverse bacterial immunity systems.

AtSAMS regulates floral organ development by DNA methylation and ethylene signaling pathway

S-adenosylmethionine synthase is the key enzyme involved in the biosynthesis of S-adenosylmethionine, which serves as the universal methyl group donor and a common precursor for the biosynthesis of ethylene and polyamines. However, little is known about how SAMS controls plant development. Here, we report that the abnormal floral organ development in the AtSAMS-overexpressing plants is caused by DNA demethylation and ethylene signaling. The whole-genome DNA methylation level decreased, and ethylene content increased in SAMOE. Wild-type plants treated with DNA methylation inhibitor mimicked the phenotypes and the ethylene levels in SAMOE, suggesting that DNA demethylation enhanced ethylene biosynthesis, which led to abnormal floral organ development. DNA demethylation and elevated ethylene resulted in changes in the expression of ABCE genes, which is essential for floral organ development. Furthermore, the transcript levels of ACE genes were highly correlated to their methylation levels, except for the down-regulation of the B gene, which might have resulted from demethylation-independent ethylene signaling. SAMS-mediated methylation and ethylene signaling might create crosstalk in the process of floral organ development. Together, we provide evidence that AtSAMS regulates floral organ development by DNA methylation and ethylene signaling pathway.

Physiological and proteomic analyses reveal the important role of arbuscular mycorrhizal fungi on enhancing photosynthesis in wheat under cadmium stress

Arbuscular mycorrhizal fungi (AMF) are important in the phytoremediation of cadmium (Cd). Improving photosynthesis under Cd stress helps to increase crop yields. However, the molecular regulatory mechanisms of AMF on photosynthetic processes in wheat (Triticum aestivum) under Cd stress remain unclear. This study utilized physiological and proteomic analyses to reveal the key processes and related genes of AMF that regulate photosynthesis under Cd stress. The results showed that AMF promoted the accumulation of Cd in the roots of wheat but significantly reduced the content of Cd in the shoots and grains. The photosynthetic rates, stomatal conductance, transpiration rates, chlorophyll content, and accumulation of carbohydrates under Cd stress were increased by AMF symbiosis. Proteomic analysis showed that AMF significantly induced the expression of two enzymes involved in the chlorophyll biosynthetic pathway (coproporphyrinogen oxidase and Mg-protoporphyrin IX chelatase), improved the expression of two proteins related to CO2 assimilation (ribulose-1,5-bisphosphate carboxylase and malic enzyme), and increased the expression of S-adenosylmethionine synthase, which positively regulates abiotic stress. Therefore, AMF may regulate photosynthesis under Cd stress by promoting chlorophyll biosynthesis, carbon assimilation, and S-adenosylmethionine metabolism.

Chromosomal Instability Causes Sensitivity to Polyamines and One-Carbon Metabolism

Aneuploidy, or having a disrupted genome, is an aberration commonly found in tumours but rare in normal tissues. It gives rise to proteotoxic stress as well as a stereotypical oxidative shift, which makes these cells sensitive to internal and environmental stresses. Using Drosophila as a model, we investigated the changes in transcription in response to ongoing changes to ploidy (chromosomal instability, CIN). We noticed changes in genes affecting one-carbon metabolism, specifically those affecting the production and use of s-adenosyl methionine (SAM). The depletion of several of these genes has led to cell death by apoptosis in CIN cells but not in normal proliferating cells. We found that CIN cells are particularly sensitive to SAM metabolism at least partly because of its role in generating polyamines. Feeding animals spermine was seen to rescue the cell death caused by the loss of SAM synthase in CIN tissues. The loss of polyamines led to decreased rates of autophagy and sensitivity to reactive oxygen species (ROS), which we have shown to contribute significantly to cell death in CIN cells. These findings suggest that a well-tolerated metabolic intervention such as polyamine inhibition has the potential to target CIN tumours via a relatively well-characterised mechanism.

Nitric oxide modulates folate-mediated one-carbon metabolism and mitochondrial energy levels of peaches during cold storage.

Folate-mediated one-carbon metabolism (FOCM) is closely associated with postharvest preservation. This study investigated the effects of exogenous nitric oxide (NO) on FOCM, storage quality, energy metabolism, and mitochondrial membrane integrity in cold-storage peach fruit. In this experiment, peaches were soaked with 1.5 mmol L-1S-nitrosoglutathione (GSNO) as NO donor, and the negative treatment (NT) solution containing 5 μmol L-1 carboxy-PTIO (c-PTIO, NO scavenger), 200 μmol L-1 NG-Nitro-L-arginine methyl ester (L-NAME, NO synthase-like enzyme inhibitor), and 200 μmol L-1 sodium tungstate dihydrate (nitrate reductase inhibitor) and stored at 0°C. The results showed that NO decreased the activity of S-adenosylmethionine synthase and S-adenosylhomocysteine hydrolase and increased the activity of methionine sulfoxide reductase A, as well as the content of N5-methyl-THF, the ratio of tetrahydrofolate (THF), homocysteine, methionine, S-adenosylmethionine (SAM), and SAM to S-adenosylhomocysteine compared with the control, indicating that NO effectively increased FOCM flux by affecting the activity of FOCM enzymes. Meanwhile, NO increased the activities of H+-ATPase, Ca2+-ATPase, cytochrome c oxidase, succinate dehydrogenase, and the contents of adenosine triphosphate and adenosine diphosphate, and maintained high energy charge in peaches during storage. NO retarded the increase in mitochondrial permeability transition, reactive oxygen species content, and the decrease in mitochondrial membrane fluidity, membrane potential, and swelling. NT treatment exhibited the opposite results. In conclusion, these results suggested that NO could induce the accumulation of folate and FOCM flux and maintain mitochondrial energy levels, which might be responsible for maintaining the quality of peaches during cold storage.

METTL16, an evolutionarily conserved m6A methyltransferase member, inhibits the antiviral immune response of miiuy croaker (Miichthys miiuy)

Methyltransferase like-16 (METTL16) is an m6A RNA methylation transferase that is known to methylate U6 snRNA and pre-mRNA of S-adenosylmethionine synthase but has been poorly studied in fish. In this study, METTL16 was identified in miiuy croaker (Miichthys miiuy). We first performed bioinformatics analysis of the miiuy croaker METTL16 (mmiMETTL16). MmiMETTL16 and other vertebrates METTL16 have a relatively conserved MTD structural domain and gene structure, suggesting that their methylase activity may also be conservative. In healthy miiuy croaker, mmiMETTL16 was commonly expressed in the tested tissues. Expression of mmiMETTL16 in kidney, liver, and spleen tissues was significantly increased after poly(I:C) stimulation. Consistently, mmiMETTL16 was sensitive to poly(I:C) stimulation in miiuy croaker kidney cell (MKC), suggesting that METTL16 might participate in antiviral immunity. For further functional experiments, immunofluorescence of mmiMETTL16 presents in the nucleus in kidney cells. In addition, the overexpression of mmiMETTL16 could significantly increase the overall m6A level of MKC cells, which shows that the function of METTL16 as methyltransferase is conservative in miiuy croaker. Last, mmiMETTL16 can inhibit the expression of TNF-α, IFN-1, Mx1, and ISG15, suggesting that mmiMETTL16 can suppress the immune response caused by viral stimulation. In summary, studies on mmiMETTL16 will contribute to future studies on the role of METTL16 and potential mechanisms of the m6A regulation network in the teleost immune system.

Elevated methylglyoxal levels inhibit tomato fruit ripening by preventing ethylene biosynthesis.

Methylglyoxal (MG), a toxic compound produced as a by-product of several cellular processes, such as respiration and photosynthesis, is well known for its deleterious effects, mainly through glycation of proteins during plant stress responses. However, very little is known about its impact on fruit ripening. Here, we found that MG levels are maintained at high levels in green tomato (Solanum lycopersicum L.) fruits and decline during fruit ripening despite a respiratory burst during this transition. We demonstrate that this decline is mainly mediated through a glutathione-dependent MG detoxification pathway and primarily catalyzed by a Glyoxalase I enzyme encoded by the SlGLYI4 gene. SlGLYI4 is a direct target of the MADS-box transcription factor RIPENING INHIBITOR (RIN), and its expression is induced during fruit ripening. Silencing of SlGLYI4 leads to drastic MG overaccumulation at ripening stages of transgenic fruits and interferes with the ripening process. MG most likely glycates and inhibits key enzymes such as methionine synthase and S-adenosyl methionine synthase in the ethylene biosynthesis pathway, thereby indirectly affecting fruit pigmentation and cell wall metabolism. MG overaccumulation in fruits of several nonripening or ripening-inhibited tomato mutants suggests that the tightly regulated MG detoxification process is crucial for normal ripening progression. Our results underpin a SlGLYI4-mediated regulatory mechanism by which MG detoxification controls fruit ripening in tomato.

Combined nitrogen and drought stress leads to overlapping and unique proteomic responses in potato

Main conclusionNitrogen deficient and drought-tolerant or sensitive potatoes differ in proteomic responses under combined (NWD) and individual stresses. The sensitive genotype ‘Kiebitz’ exhibits a higher abundance of proteases under NWD.Abiotic stresses such as N deficiency and drought affect the yield of Solanum tuberosum L. tremendously. Therefore, it is of importance to improve potato genotypes in terms of stress tolerance. In this study, we identified differentially abundant proteins (DAPs) in four starch potato genotypes under N deficiency (ND), drought stress (WD), or combined stress (NWD) in two rain-out shelter experiments. The gel-free LC–MS analysis generated a set of 1177 identified and quantified proteins. The incidence of common DAPs in tolerant and sensitive genotypes under NWD indicates general responses to this stress combination. Most of these proteins were part of the amino acid metabolism (13.9%). Three isoforms of S-adenosyl methionine synthase (SAMS) were found to be lower abundant in all genotypes. As SAMS were found upon application of single stresses as well, these proteins appear to be part of the general stress response in potato. Interestingly, the sensitive genotype ‘Kiebitz’ showed a higher abundance of three proteases (subtilase, carboxypeptidase, subtilase family protein) and a lower abundance of a protease inhibitor (stigma expressed protein) under NWD stress compared to control plants. The comparably tolerant genotype ‘Tomba’, however, displayed lower abundances of proteases. This indicates a better coping strategy for the tolerant genotype and a quicker reaction to WD when previously stressed with ND.

Utilization of high-K+-cane molasses for enhanced S-Adenosylmethionine production by manipulation of a K+ transport channel in Saccharomyces cerevisiae

S-Adenosylmethionine (SAM) is a valuable compound extensively used in depression treatment and biological methyl donor, which is biosynthesized from ATP and L-methionine with SAM synthase (SAM-s) as a catalyst. In this research, the weak SAM-s activity was a key factor and led to low SAM titer in Saccharomyces cerevisiae. Then, a novel K+ uptake channel was introduced to the SAM production pathway of Saccharomyces cerevisiae, activated by K+ in molasses to enhance the SAM synthase (SAM-s) activity and thereby improve the production efficiency of SAM. As a result, the intracellular K+ concentration and SAM-s activity were 1.23- and 1.31-fold higher than the control leading to a 24 % increase to 0.93 ± 0.04 g/L in SAM titer. In combination with bioprocess optimization resulted in a final yield of 2.22 ± 0.01 g/L in shake flasks and 15.37 ± 0.89 g/L in a 5-L bioreactor from pretreated molasses. This work provides a practical and cost-effective strategy for the large-scale biosynthesis of SAM from cane molasses.

Proteoform Identification in 2D Electrophoresis Maps by Using Isoelectric Point Prediction

The possibility of identifying specific protein proteoforms with post-translational modifications (PTM) by analyzing two-dimensional (2D) gel electrophoresis maps and using the prediction of the isoelectric point of proteins (pI) has been investigated. The pI values were predicted using the pIPredict 3 program, supporting a wide range of chemical and post-translational modifications. Eleven 11 proteins (albumin, alpha-1-microglobulin, annexin A2, apolipoprotein E, gastric triacylglycerol lipase, mitochondrial isocitrate dehydrogenase, clusterin, plasmin, prothrombin, endoplasmic reticulum chaperone, S-adenosylmethionine synthase type 1) identified on six 2D electrophoresis maps were used as examples. Various options for selecting hypotheses are considered. These take into consideration the following available information about a particular protein: possible modification sites, processing features, variability of the amino acid composition. The obtained results indicate that the use of predicting the pI value for proteins with hypothetical PTMs can form a set of hypotheses about specific proteoform occurrence on 2D electrophoresis maps.

Decipher the molecular evolution and expression patterns of Cupin family genes in oilseed rape

Cupin proteins are involved in plant growth and development as well as in response to various stresses. Here, a total of 173 Cupin genes were identified in Brassica napus, and their molecular evolution and expression patterns were analyzed. These genes were classified into ten groups. Motif and exon-intron structure indicated a high degree of conservation within each group during evolution. BnaCupins were distributed on 19 chromosomes and their expansion is mainly contributed by whole-genome duplication (WGD) and segmental duplication events. BnaCupins have undergone severe purifying selection during a long evolutionary process. Meanwhile, some positive selection sites were identified. Expression patterns and cis-element analysis indicated that BnaCupins play significant roles in plant growth and stress responses. In addition, the expression levels of some BnCupins were significantly altered when treated with different conditions (cold, salt, drought, IAA, ABA, and 6-BA). Some BnaCupin interacting proteins, such as glycosyl hydrolase5 (GHs5), carbohydrate kinase (CHKs), ATP-dependent 6-phosphofructokinase (ATP-PFK), S-adenosylmethionine synthase (S-MAT), and aldolase class II (ALD II), were identified by the protein-protein interaction network. It will contribute to enriching our knowledge of the Cupin gene family in B. napus and provide a basis for further studies of their functions.

Expression of PmACRE1 in Arabidopsis thaliana enables host defence against Bursaphelenchus xylophilus infection

BackgroundPine wilt disease (PWD) is a destructive disease that endangers pine trees, resulting in the wilting, with yellowing and browning of the needles, and eventually the death of the trees. Previous studies showed that the Avr9/Cf-9 rapidly elicited (PmACRE1) gene was downregulated by Bursaphelenchus xylophilus infection, suggesting a correlation between PmACRE1 expression and pine tolerance. Here, we used the expression of PmACRE1 in Arabidopsis thaliana to evaluate the role of PmACRE1 in the regulation of host defence against B. xylophilus infection.ResultsOur results showed that the transformation of PmACRE1 into A. thaliana enhanced plant resistance to the pine wood nematode (PWN); that is, the leaves of the transgenic line remained healthy for a longer period than those of the blank vector group. Ascorbate peroxidase (APX) activity and total phenolic acid and total flavonoid contents were higher in the transgenic line than in the control line. Widely targeted metabolomics analysis of the global secondary metabolites in the transgenic line and the vector control line showed that the contents of 30 compounds were significantly different between these two lines; specifically, the levels of crotaline, neohesperidin, nobiletin, vestitol, and 11 other compounds were significantly increased in the transgenic line. The studies also showed that the ACRE1 protein interacted with serine hydroxymethyltransferase, catalase domain-containing protein, myrosinase, dihydrolipoyl dehydrogenase, ketol-acid reductoisomerase, geranylgeranyl diphosphate reductase, S-adenosylmethionine synthase, glutamine synthetase, and others to comprehensively regulate plant resistance.ConclusionsTaken together, these results indicate that PmACRE1 has a potential role in the regulation of plant defence against PWNs.

Bioengineering of Escherichia coli Nissle 1917 for Production and Excretion of Spermidine, a Key Metabolite in Human Health.

Microbiota-derived metabolites have biological importance for their host. Spermidine, a metabolite described for its protective effect in age-related diseases, is now studied for its role in the resolution of inflammation and gut homeostasis. Strategies to modulate its production in the gastrointestinal tract are of interest to increase host spermidine intakes. Here, we show that metabolic engineering can be used to increase spermidine production by the probiotic Escherichia coli Nissle 1917 (EcN), used in humans. First, we found that increasing the expression of genes involved in polyamine biosynthesis, namely the S-adenosylmethionine synthase speD and the spermidine synthase speE, resulted in an increase in spermidine produced and excreted by our engineered bacteria. The major drawback of this first attempt was the production of acetylated forms of spermidine. Next, we propose to solve this problem by increasing the expression of the spermidine exporter system MdtI/MdtJ. This second strategy had a major impact on the spermidine profile found in the culture supernatant. Our results demonstrate, for the first time, the feasibility of rationally engineering bacterial probiotic strains to increase their ability to deliver the microbiota-derived metabolite, spermidine. This work illustrates how metabolomic and synthetic biology can be used to design and improve engineered Live Biotherapeutic Products that have the potential to be used in personalized medicine.

S-adenosylmethionine synthase-derived GR15 peptide suppresses proliferation of breast cancer cells by upregulating the caspase-mediated apoptotic pathway: In vitro and in silico analyses

IntroductionGR15 peptide is a potential antioxidant peptide which reduces intercellular ROS levels in zebrafish larvae stressed with H2O2. Cancer is a condition which develops during oxidative stress due to various reasons. Antioxidant molecules promote apoptosis or inhibit cancer cell proliferation by regulating the ROS level in cancer cells. This study identifies the anti-cancer potency of GR15 peptide derived from S-adenosylmethionine synthase of spirulina, Arthrospira platensis. We examined the anti-cancer property of this antioxidant peptide against breast cancer cells, MCF-7. MethodsAn in-vitro anticancer activity of GR15 peptide was investigated by performing the following assays: MTT, Trypan blue assay, LDH assay and IC50 value calculation. Moreover, we examined the morphology of cancer cells under inverted microscope due to apoptosis staining AO/PI. The inter-cellular cancer level was measured by DCFDA staining, and the mitochondrial membrane potential was determined by Rhodamine 123. Further, the FACS analysis was performed to identify the changes in the cell cycle phases. Altered mRNA expressions of anti-cancer genes including Bcl-2, BAX, Caspase 3 and Caspase 9 were also addressed. ResultsThe GR15 peptide exhibit dose-dependent activity on MCF-7 cells. The MTT assay revealed that the GR15 peptide treatment at 45 µM showed 57 % inhibition of cancer cell proliferation. Also, the peptide significantly affects the cellular morphology and promotes apoptosis. GR15 treatment reduces the ROS level in a dose-dependent manner. The peptide is also exhibited mitochondrial membrane potential activity. As GR15 significantly upregulated the anti-cancer gene expression, an in-silico analysis was carried out to validate the anti-cancer activity. The molecular docking of GR15 showed good binding scores and significant amino acid interaction with the respective receptors. ConclusionThis study suggested that GR15 potentiates anticancer activity. It reduces ROS and subsequently regulates caspase-mediated apoptosis. Overall, the observations suggested that GR15 could be an anti-cancer peptide; however, further studies on in-vivo mammalian model or clinical trials need to be performed to prove the claims.

Label-Free Quantitative Proteomics Reveal the Involvement of PRT6 in Arabidopsis thaliana Seed Responsiveness to Ethylene

In Arabidopsis thaliana, the breaking of seed dormancy in wild type (Col-0) by ethylene at 100 μL L−1 required at least 30 h application. A mutant of the proteolytic N-degron pathway, lacking the E3 ligase PROTEOLYSIS 6 (PRT6), was investigated for its role in ethylene-triggered changes in proteomes during seed germination. Label-free quantitative proteomics was carried out on dormant wild type Col-0 and prt6 seeds treated with (+) or without (−) ethylene. After 16 h, 1737 proteins were identified, but none was significantly different in protein levels in response to ethylene. After longer ethylene treatment (30 h), 2552 proteins were identified, and 619 Differentially Expressed Proteins (DEPs) had significant differences in protein abundances between ethylene treatments and genotypes. In Col, 587 DEPs were enriched for those involved in signal perception and transduction, reserve mobilization and new material generation, which potentially contributed to seed germination. DEPs up-regulated by ethylene in Col included S-adenosylmethionine synthase 1, methionine adenosyltransferase 3 and ACC oxidase involved in ethylene synthesis and of Pyrabactin Resistance1 acting as an ABA receptor, while DEPs down-regulated by ethylene in Col included aldehyde oxidase 4 involved in ABA synthesis. In contrast, in prt6 seeds, ethylene did not result in strong proteomic changes with only 30 DEPs. Taken together, the present work demonstrates that the proteolytic N-degron pathway is essential for ethylene-mediated reprogramming of seed proteomes during germination.