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Scientific Reports Jun 2020In solid tumors, hypoxia can trigger aberrant expression of transcription factors and genes, resulting in abnormal biological functions such as altered energetic...
In solid tumors, hypoxia can trigger aberrant expression of transcription factors and genes, resulting in abnormal biological functions such as altered energetic pathways in cancer cells. Glucose metabolism is an important part of this phenomenon, which is associated with changes in the functional expression of transporters and enzymes involved in the glycolysis pathway. The latter phenomenon can finally lead to the lactate accumulation and pH dysregulation in the tumor microenvironment and subsequently further invasion and metastasis of cancer cells. Having capitalized on the computational modeling, in this study, for the first time, we aimed to investigate the effects of hypoxia-induced factor-1 (HIF-1) mediated hypoxia on the magnitude of functional expression of all the enzymes and transporters involved in the glycolysis process. The main objective was to establish a quantitative relationship between the hypoxia intensity and the intracellular lactate levels and determine the key regulators of the glycolysis pathway. This model clearly showed an increase in the lactate concentration during the oxygen depletion. The proposed model also predicted that the phosphofructokinase-1 and phosphoglucomutase enzymes might play the most important roles in the regulation of the lactate production.
Topics: Gene Expression; Glycolysis; Humans; Hypoxia; Hypoxia-Inducible Factor 1, alpha Subunit; Lactic Acid; Models, Theoretical; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasms; Phosphofructokinase-1; Phosphoglucomutase; Signal Transduction; Tumor Microenvironment
PubMed: 32514127
DOI: 10.1038/s41598-020-66059-w -
Annals of Botany Nov 2023Crassulacean acid metabolism (CAM) is a specialized type of photosynthesis characterized by a diel pattern of stomatal opening at night and closure during the day, which...
The starch-deficient plastidic PHOSPHOGLUCOMUTASE mutant of the constitutive crassulacean acid metabolism (CAM) species Kalanchoë fedtschenkoi impacts diel regulation and timing of stomatal CO2 responsiveness.
BACKGROUND AND AIMS
Crassulacean acid metabolism (CAM) is a specialized type of photosynthesis characterized by a diel pattern of stomatal opening at night and closure during the day, which increases water-use efficiency. Starch degradation is a key regulator of CAM, providing phosphoenolpyruvate as a substrate in the mesophyll for nocturnal assimilation of CO2. Growing recognition of a key role for starch degradation in C3 photosynthesis guard cells for mediating daytime stomatal opening presents the possibility that starch degradation might also impact CAM by regulating the provision of energy and osmolytes to increase guard cell turgor and drive stomatal opening at night. In this study, we tested the hypothesis that the timing of diel starch turnover in CAM guard cells has been reprogrammed during evolution to enable nocturnal stomatal opening and daytime closure.
METHODS
Biochemical and genetic characterization of wild-type and starch-deficient RNAi lines of Kalanchoë fedtschenkoi with reduced activity of plastidic phosphoglucomutase (PGM) constituted a preliminary approach for the understanding of starch metabolism and its implications for stomatal regulation in CAM plants.
KEY RESULTS
Starch deficiency reduced nocturnal net CO2 uptake but had negligible impact on nocturnal stomatal opening. In contrast, daytime stomatal closure was reduced in magnitude and duration in the starch-deficient rPGM RNAi lines, and their stomata were unable to remain closed in response to elevated concentrations of atmospheric CO2 administered during the day. Curtailed daytime stomatal closure was linked to higher soluble sugar contents in the epidermis and mesophyll.
CONCLUSIONS
Nocturnal stomatal opening is not reliant upon starch degradation, but starch biosynthesis is an important sink for carbohydrates, ensuring daytime stomatal closure in this CAM species.
Topics: Crassulacean Acid Metabolism; Kalanchoe; Phosphoglucomutase; Carbon Dioxide; Starch; Photosynthesis
PubMed: 36661206
DOI: 10.1093/aob/mcad017 -
International Journal of Peptide... 2021infection is a leading cause of mortality and morbidity in community, hospital and live-stock sectors, especially with the widespread emergence of...
Integrated Multi-omics, Virtual Screening and Molecular Docking Analysis of Methicillin-Resistant USA300 for the Identification of Potential Therapeutic Targets: An In-Silico Approach.
UNLABELLED
infection is a leading cause of mortality and morbidity in community, hospital and live-stock sectors, especially with the widespread emergence of methicillin-resistant . (MRSA) strains. To identify new drug molecules to treat MRSA patients, we have undertaken to search essential proteins that are indispensable for their survival but non-homologous to human host proteins. The current study utilizes a subtractive genome and proteome approach to screen the possible therapeutic targets against . USA300. Bacterial essential genes are obtained from the DEG database and are compared to avoid cross-reactivity with human host genes. In silico analysis shows 198 proteins that may be considered as therapeutic candidates. Depending on their sub-cellular localization, proteins are grouped as either vaccine or drug targets or both. Extracellular proteins such as cell division proteins (Q2FZ91, Q2FZ95), penicillin-binding proteins (Q2FZ94, Q2FYI0) of the bacterial cell wall, phosphoglucomutase (Q2FE11) and lipoteichoic acid synthase (Q2FIS2) are considered as vaccine targets, and their epitopes have been mapped. Altogether, 53 drug targets are identified, which have shown similarity with the drug targets available in the DrugBank database. Predicted drug targets belong to the common metabolic pathways of MRSA, such as fatty acid biosynthesis, folate biosynthesis, peptidoglycan biosynthesis, ribosome, etc. Protein-protein interaction analysis emphasizing peptidoglycan biosynthesis reveals the connection between penicillin-binding proteins, mur-family proteins and FemXAB proteins. In this study, staphylococcal FemA protein (P0A0A5) is subjected to structure-based virtual screening for the drug repurposing approach. There are 20 residues missing in the crystal structure of FemA, and 12 of these residues are located at the catalytic site. The missing residues are modelled, and stereochemistry is checked. FDA approved drugs available in the DrugBank database have been used in virtual screening with FemA in search of potential repurposed molecules. This approach provides us with 10 drugs that may be used in the treatment of methicillin-resistant staphylococcal mediated diseases. AutoDock 4.2 is used for in silico screening and shows a comparable inhibition constant (Ki) for all 10 FDA-approved drugs towards FemA. Most of these drugs are used in the treatment of various cancers, migraines and leukaemia. Protein-drug interaction analysis shows that the drugs mostly interact with hydrophobic residues of FemA. Moreover, Tyr328 and Lys383 contribute largely to hydrogen bondings during interactions. All interacting amino acids that bind to the drugs are part of the active site cavity of FemA.
SUPPLEMENTARY INFORMATION
The online version contains supplementary material available at 10.1007/s10989-021-10287-9.
PubMed: 34548853
DOI: 10.1007/s10989-021-10287-9 -
The Journal of Biological Chemistry Nov 2021Cyclic-di-adenosine monophosphate (c-di-AMP) is an important nucleotide signaling molecule that plays a key role in osmotic regulation in bacteria. c-di-AMP is produced...
Cyclic-di-adenosine monophosphate (c-di-AMP) is an important nucleotide signaling molecule that plays a key role in osmotic regulation in bacteria. c-di-AMP is produced from two molecules of ATP by proteins containing a diadenylate cyclase (DAC) domain. In Bacillus subtilis, the main c-di-AMP cyclase, CdaA, is a membrane-linked cyclase with an N-terminal transmembrane domain followed by the cytoplasmic DAC domain. As both high and low levels of c-di-AMP have a negative impact on bacterial growth, the cellular levels of this signaling nucleotide are tightly regulated. Here we investigated how the activity of the B. subtilis CdaA is regulated by the phosphoglucomutase GlmM, which has been shown to interact with the c-di-AMP cyclase. Using the soluble B. subtilis CdaA catalytic domain and purified full-length GlmM or the GlmM variant lacking the C-terminal flexible domain 4, we show that the cyclase and phosphoglucomutase form a stable complex in vitro and that GlmM is a potent cyclase inhibitor. We determined the crystal structure of the individual B. subtilis CdaA and GlmM homodimers and of the CdaA:GlmM complex. In the complex structure, a CdaA dimer is bound to a GlmM dimer in such a manner that GlmM blocks the oligomerization of CdaA and formation of active head-to-head cyclase oligomers, thus suggesting a mechanism by which GlmM acts as a cyclase inhibitor. As the amino acids at the CdaA:GlmM interphase are conserved, we propose that the observed mechanism of inhibition of CdaA by GlmM may also be conserved among Firmicutes.
Topics: Bacillus subtilis; Bacterial Proteins; Crystallography, X-Ray; Multienzyme Complexes; Phosphoglucomutase; Phosphorus-Oxygen Lyases; Protein Domains; Protein Multimerization; Protein Structure, Quaternary
PubMed: 34678313
DOI: 10.1016/j.jbc.2021.101317 -
Turkish Journal of Biology = Turk... 2022Diabetes resulting from insufficient insulin secretion or insulin resistance (IR) is a highly prevalent metabolic disease. Since microRNAs have been linked with elevated...
Palmitic acid declines glucose uptake in HepG2 cells via modulating phosphoglucomutase 1 to repress phosphatidylinositol 3 kinase/protein kinase B and JNK pathways via inducing microRNA-124-3p.
Diabetes resulting from insufficient insulin secretion or insulin resistance (IR) is a highly prevalent metabolic disease. Since microRNAs have been linked with elevated IR, the current research hypothesized that miR-124-3p has a role in IR and the establishment of IR and type 2 diabetes (T2DM). The study aimed to explore the molecular mechanisms of miR-124-3p which influence IR leading to T2DM establishment. HepG2 cells were cultured in vitro, and palmitic acid (PA) was used to construct the IR cell model. In the IR model, transfection of miR-124-3p or phosphoglucomutase 1 (PGM1) linked plasmids were transfected into HepG2 cells. RT-qPCR was used to determine the miR-124-3p and PGM1 expressions in the cells. Cell viability was assessed through CCK-8 assays, while glucose consumption was studied using a glucose uptake test. Interaction between miR-124-3p and PGM1 was examined using a dual-luciferase reporter assay. Autophagy, phosphatidylinositol 3 kinases (PI3K)/protein kinase B (AKT) and JNK pathways-linked factors, glucose transporter 4 (GLUT4), and c-Jun were determined through western blotting assays. MiR-124-3p expression was elevated, but PGM1 was reduced in the IR model. Glucose uptake was reduced posttreatment with 0.8 mM PA. There was a significantly increased PI3K, p-PI3K, AKT, p-AKT, GLUT4, LC3I/II, Beclin-1, p-JNK1/2, and c-Jun, but reduced p62 expressions were presented in the PA + miR-124-3p inhibitor compared to the PA and PA + inhibitor NC groups. PGM1 binds directly to miR-124-3p through the 3' UTR region target. Overall, miR-124-3p downregulates glucose consumption via targeting PGM1 to repress PI3K/AKT and JNK pathways. Silencing PGM1 inhibited the suppressor role of miR-124-3p on glucose uptake, cell proliferation, and inflammation. In conclusion, miR-124-3p reduces glucose uptake in HepG2 cells via PGM1/PI3K/AKT modulation. MiR-124-3p targets PGM1 in IR and may provide an effective therapeutic alternative for T2DM.
PubMed: 37529096
DOI: 10.55730/1300-0152.2618 -
Journal of Bacteriology Jun 2021
Topics: Bacterial Capsules; Biosynthetic Pathways; Phosphoglucomutase; Streptococcus pneumoniae
PubMed: 34100630
DOI: 10.1128/JB.00220-21 -
JIMD Reports Mar 2023We report successful heart transplantation in a phosphoglucomutase 1 deficient (PGM1-CDG) patient. She presented with facial dysmorphism, bifid uvula and structural...
We report successful heart transplantation in a phosphoglucomutase 1 deficient (PGM1-CDG) patient. She presented with facial dysmorphism, bifid uvula and structural heart defects. Newborn screening was positive for classic galactosemia. The patient was on a galactose-free diet for 8 months. Eventually, whole exome sequencing excluded the galactosemia and revealed PGM1-CDG. Oral D-galactose therapy was started. Rapid deterioration of the progressive dilated cardiomyopathy prompted heart transplantation at the age of 12 months. Cardiac function was stable in the first 18 months of follow-up, and hematologic, hepatic, and endocrine laboratory findings improved during D-galactose therapy. The latter therapy improves several systemic symptoms and biochemical abnormalities in PGM1-CDG but does not correct the heart failure related to cardiomyopathy. Heart transplantation has so far only been described in DOLK-CDG.
PubMed: 36873091
DOI: 10.1002/jmd2.12350 -
Carbohydrate Research Feb 2020Trehalose 6-phosphate (Tre6P) is an important intermediate for trehalose biosynthesis. Recent researches have revealed that Tre6P is an endogenous signaling molecule...
Trehalose 6-phosphate (Tre6P) is an important intermediate for trehalose biosynthesis. Recent researches have revealed that Tre6P is an endogenous signaling molecule that regulates plant development and stress responses. The necessity of Tre6P in physiological studies is expected to be increasing. To achieve the cost-effective production of Tre6P, a novel approach is required. In this study, we utilized trehalose 6-phosphate phosphorylase (TrePP) from Lactococcus lactis to produce Tre6P. In the reverse phosphorolysis by the TrePP, 91.9 mM Tre6P was produced from 100 mM β-glucose 1-phosphate (β-Glc1P) and 100 mM glucose 6-phosphate (Glc6P). The one-pot reaction of TrePP and maltose phosphorylase (MP) enabled production of 65 mM Tre6P from 100 mM maltose, 100 mM Glc6P, and 20 mM inorganic phosphate. Addition of β-phosphoglucomutase to this reaction produced Glc6P from β-Glc1P and thus reduced requirement of Glc6P as a starting material. Within the range of 20-469 mM inorganic phosphate tested, the 54 mM concentration yielded the highest amount of Tre6P (33 mM). Addition of yeast increased the yield because of its glucose consumption. Finally, from 100 mmol maltose and 60 mmol inorganic phosphate, we successfully achieved production of 37.5 mmol Tre6P in a one-pot reaction (100 mL), and 9.4 g Tre6P dipotassium salt was obtained.
Topics: Bacterial Proteins; Carbohydrate Metabolism; Cloning, Molecular; Glucose-6-Phosphatase; Glucosephosphates; Glucosyltransferases; Lactococcus lactis; Phosphates; Sugar Phosphates; Trehalose; Yeasts
PubMed: 31911362
DOI: 10.1016/j.carres.2019.107902 -
Kidney International Apr 2020Hypoxia-inducible factor (HIF) mediates protection via hypoxic preconditioning in both, in vitro and in vivo ischemia models. However, the underlying mechanism remains...
Hypoxia-inducible factor (HIF) mediates protection via hypoxic preconditioning in both, in vitro and in vivo ischemia models. However, the underlying mechanism remains largely unknown. Prolyl hydroxylase domain proteins serve as the main HIF regulator via hydroxylation of HIFα leading to its degradation. At present, prolyl hydroxylase inhibitors including enarodustat are under clinical trials for the treatment of renal anemia. In an in vitro model of ischemia produced by oxygen-glucose deprivation of renal proximal tubule cells in culture, enarodustat treatment and siRNA knockdown of prolyl hydroxylase 2, but not of prolyl hydroxylase 1 or prolyl hydroxylase 3, significantly increased the cell viability and reduced the levels of reactive oxygen species. These effects were offset by the simultaneous knockdown of HIF1α. In another in vitro ischemia model induced by the blockade of oxidative phosphorylation with rotenone/antimycin A, enarodustat-enhanced glycogen storage prolonged glycolysis and delayed ATP depletion. Although autophagy is another possible mechanism of prolyl hydroxylase inhibition-induced cytoprotection, gene knockout of a key autophagy associated protein, Atg5, did not affect the protection. Enarodustat increased the expression of several enzymes involved in glycogen synthesis, including phosphoglucomutase 1, glycogen synthase 1, and 1,4-α glucan branching enzyme. Increased glycogen served as substrate for ATP and NADP production and augmented reduction of glutathione. Inhibition of glycogen synthase 1 and glutathione reductase nullified enarodustat's protective effect. Enarodustat also protected the kidneys in a rat ischemia reperfusion injury model and the protection was partially abrogated by inhibiting glycogenolysis. Thus, prolyl hydroxylase inhibition protects the kidney from ischemia via upregulation of glycogen synthesis.
Topics: Animals; Glycogen; Hypoxia-Inducible Factor 1, alpha Subunit; Ischemia; Kidney; N-substituted Glycines; Prolyl Hydroxylases; Pyridines; Rats; Triazoles; Up-Regulation
PubMed: 32033782
DOI: 10.1016/j.kint.2019.10.020 -
Nature Communications Nov 2020Enzyme regulation is vital for metabolic adaptability in living systems. Fine control of enzyme activity is often delivered through post-translational mechanisms, such...
Enzyme regulation is vital for metabolic adaptability in living systems. Fine control of enzyme activity is often delivered through post-translational mechanisms, such as allostery or allokairy. β-phosphoglucomutase (βPGM) from Lactococcus lactis is a phosphoryl transfer enzyme required for complete catabolism of trehalose and maltose, through the isomerisation of β-glucose 1-phosphate to glucose 6-phosphate via β-glucose 1,6-bisphosphate. Surprisingly for a gatekeeper of glycolysis, no fine control mechanism of βPGM has yet been reported. Herein, we describe allomorphy, a post-translational control mechanism of enzyme activity. In βPGM, isomerisation of the K145-P146 peptide bond results in the population of two conformers that have different activities owing to repositioning of the K145 sidechain. In vivo phosphorylating agents, such as fructose 1,6-bisphosphate, generate phosphorylated forms of both conformers, leading to a lag phase in activity until the more active phosphorylated conformer dominates. In contrast, the reaction intermediate β-glucose 1,6-bisphosphate, whose concentration depends on the β-glucose 1-phosphate concentration, couples the conformational switch and the phosphorylation step, resulting in the rapid generation of the more active phosphorylated conformer. In enabling different behaviours for different allomorphic activators, allomorphy allows an organism to maximise its responsiveness to environmental changes while minimising the diversion of valuable metabolites.
Topics: Allosteric Regulation; Allosteric Site; Crystallography, X-Ray; Enzyme Assays; Glucose-6-Phosphate; Glucosephosphates; Glycolysis; Isomerism; Kinetics; Molecular Conformation; Phosphorylation; Phosphotransferases (Phosphomutases); Proline; Protein Domains; Protein Processing, Post-Translational; Proton Magnetic Resonance Spectroscopy; Recombinant Proteins
PubMed: 33139716
DOI: 10.1038/s41467-020-19215-9