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Experimental Biology and Medicine... Sep 2022The hexosamine biosynthetic pathway (HBP) is connected to abnormal N- and O-linked protein glycosylation in cancer, which performs critical roles in tumorigenesis....
The hexosamine biosynthetic pathway (HBP) is connected to abnormal N- and O-linked protein glycosylation in cancer, which performs critical roles in tumorigenesis. However, the regulation mechanisms of HBP and its role in colorectal cancer (CRC) progression remain unexplained. This study analyzed the expression level of phosphoglucomutase 3 (PGM3), a key enzyme in HBP, and identified its function in CRC cell lines. Analysis of publicly available CRC microarray data determined that PGM3 is upregulated in CRC tumor tissues. Furthermore, functional experiments emphasized the significant roles of PGM3 in facilitating CRC cell proliferation and migration. Mechanistically, we demonstrated that the activity of β-catenin in CRC was maintained by PGM3-mediated O-GlcNAcylation. PGM3 knockdown or inhibition of O-GlcNAc transferase decreased β-catenin activity and the expression levels of its downstream targets. Collectively, our findings indicate that PGM3 exhibits tumor-promoting roles by elevating O-GlcNAcylation level and maintaining β-catenin activity, and might serve as a prognostic biomarker and treatment target in CRC.
Topics: Biomarkers; Cell Line, Tumor; Cell Movement; Cell Proliferation; Cell Transformation, Neoplastic; Colorectal Neoplasms; Gene Expression Regulation, Neoplastic; Hexosamines; Humans; Phosphoglucomutase; Wnt Signaling Pathway; beta Catenin
PubMed: 35723049
DOI: 10.1177/15353702221101810 -
Journal of Applied Microbiology Oct 2018The aim of this study was to screen vaccine candidates from virulence factors of Streptococcus iniae in flounder model.
Recombinant phosphoglucomutase and CAMP factor as potential subunit vaccine antigens induced high protection against Streptococcus iniae infection in flounder (Paralichthys olivaceus).
AIMS
The aim of this study was to screen vaccine candidates from virulence factors of Streptococcus iniae in flounder model.
METHODS AND RESULTS
The immunogenicity of recombinant phosphoglucomutase (rPGM) and rCAMP factor was confirmed by Western blot. The percentage of surface membrane immunoglobulin-positive (sIg ) lymphocytes in peripheral blood leucocytes, the specific and total serum IgM and the activity of acid phosphatase (ACP) and peroxidase (POD) in flounder were determined with flow cytometry, ELISA and commercial enzyme activity kits, respectively, after intraperitoneal immunization with rPGM and rCAMP factor. The results showed that rPGM and rCAMP factor could induce significant rise in sIg lymphocytes, specific serum IgM and activities of ACP and POD. Additionally, the relative percent survival rate of the vaccinated flounder was 64 and 54% in challenge experiment using S. iniae, respectively. These results indicated that rPGM and rCAMP factor could evoke humoural and innate immune response in flounder and provide high-efficiency immunoprotection against S. iniae infection.
CONCLUSIONS
Phosphoglucomutase (PGM) and CAMP factor were promising vaccine candidates against S. iniae in flounder.
SIGNIFICANCE AND IMPACT OF THE STUDY
Phosphoglucomutase and CAMP factor have the potential to be vaccine candidates, which provide important information for us to develop the effective subunit vaccines, especially the multivaccine, against S .iniae in aquaculture.
Topics: Animals; Bacterial Proteins; Bacterial Vaccines; Fish Diseases; Flounder; Hemolysin Proteins; Immunity, Innate; Phosphoglucomutase; Streptococcal Infections; Streptococcus iniae; Vaccination; Vaccines, Subunit
PubMed: 29877008
DOI: 10.1111/jam.13948 -
BMC Research Notes May 2022Toxoplasma gondii is a ubiquitous parasite of medical and veterinary importance; however, there exists no cure for chronic toxoplasmosis. Metabolic enzymes required for...
OBJECTIVE
Toxoplasma gondii is a ubiquitous parasite of medical and veterinary importance; however, there exists no cure for chronic toxoplasmosis. Metabolic enzymes required for the production and maintenance of tissue cysts represent promising targets for novel therapies. Here, we use reverse genetics to investigate the role of Toxoplasma phosphoglucomutase 1, PGM1, in Toxoplasma growth and cystogenesis.
RESULTS
We found that disruption of pgm1 did not significantly affect Toxoplasma intracellular growth and the lytic cycle. pgm1-defective parasites could differentiate into bradyzoites and produced cysts containing amylopectin in vitro. However, cysts produced in the absence of pgm1 were significantly smaller than wildtype. Together, our findings suggest that PGM1 is dispensable for in vitro growth but contributes to optimal Toxoplasma cyst development in vitro, thereby necessitating further investigation into the function of this enzyme in Toxoplasma persistence in its host.
Topics: Humans; Phosphoglucomutase; Toxoplasma; Toxoplasmosis
PubMed: 35597992
DOI: 10.1186/s13104-022-06073-5 -
The Journal of Biological Chemistry Aug 1987The enzyme phosphoglucomutase can be used as a metal ion indicator to measure the concentrations of free Mg2+ and free Zn2+ in physiological fluids. In horse plasma, the...
The enzyme phosphoglucomutase can be used as a metal ion indicator to measure the concentrations of free Mg2+ and free Zn2+ in physiological fluids. In horse plasma, the concentration of free Mg2+ is close to 0.5 mM, whereas that of free Zn2+ is about 2 X 10(-10) M, although numerous physiological roles for Zn2+ have been postulated that would require free Zn2+ concentration orders of magnitude higher than this. A titration of plasma with Zn2+ shows that the fractional increase in free Zn2+ is essentially the same as the fractional increase in total exchangeable Zn2+, and the results are consistent with a model in which essentially all of the Zn2+ in plasma is bound to albumin. Regardless of the model, the buffering capacity of plasma for free Zn2+ is intrinsically low; however, its capacity relative to the total (exchangeable) Zn2+ present is maximal. The implications of this type of buffering for homeostasis of plasma Zn2+ are considered. Treatment of plasma with a strong reducing agent such as dithiothreitol (0.1 mM) substantially increases the apparent binding of Zn2+ and thus reduces the free Zn2+ concentration. However, the concentration of free Zn2+ appears to be insensitive to decreases in the physiological concentrations of reduced glutathione and cysteine. The concentrations of free Zn2+ and free Mg2+ in plasma are similar to those that have been reported for muscle tissue (rabbit). Their ratio is about 4 X 10(-7). The physiological implications of these concentrations are considered. In some cases, if the Zn2+ and Mg2+ complexes of an uncharacterized vertebrate protein exhibit significantly different properties, their relative importance under physiological conditions can be approximated by evaluating those of the mixed complexes present in a solution that contains the physiological concentration of free Mg2+, plus Zn2+ buffered with histidine, at the appropriate pH and ionic strength. Other metal ion/chelon systems that come close to reproducing the concentrations of free Mg2+ and free Zn2+ in horse plasma also are considered.
Topics: Animals; Binding, Competitive; Cations, Divalent; Dithiothreitol; Horses; Hydrogen-Ion Concentration; Magnesium; Muscles; Phosphoglucomutase; Plasma; Protein Binding; Serum Albumin; Spectrophotometry, Atomic; Zinc
PubMed: 2956262
DOI: No ID Found -
Journal of Bacteriology Jun 2021Capsular polysaccharide (CPS) is a major virulence determinant for many human-pathogenic bacteria. Although the essential functional roles for CPS in bacterial virulence...
Capsular polysaccharide (CPS) is a major virulence determinant for many human-pathogenic bacteria. Although the essential functional roles for CPS in bacterial virulence have been established, knowledge of how CPS production is regulated remains limited. Streptococcus pneumoniae (pneumococcus) CPS expression levels and overall thickness change in response to available oxygen and carbohydrate. These nutrients in addition to transition metal ions can vary significantly between host environmental niches and infection stage. Since the pneumococcus must modulate CPS expression among various host niches during disease progression, we examined the impact of the nutritional transition metal availability of manganese (Mn) and zinc (Zn) on CPS production. We demonstrate that increased Mn/Zn ratios increase CPS production via Mn-dependent activation of the phosphoglucomutase Pgm, an enzyme that functions at the branch point between glycolysis and the CPS biosynthetic pathway in a transcription-independent manner. Furthermore, we find that the downstream CPS protein CpsB, an Mn-dependent phosphatase, does not promote aberrant dephosphorylation of its target capsule-tyrosine kinase CpsD during Mn stress. Together, these data reveal a direct role for cellular Mn/Zn ratios in the regulation of CPS biosynthesis via the direct activation of Pgm. We propose a multilayer mechanism used by the pneumococcus in regulating CPS levels across various host niches. Evolving evidence strongly indicates that maintenance of metal homeostasis is essential for establishing colonization and continued growth of bacterial pathogens in the vertebrate host. In this study, we demonstrate the impact of cellular manganese/zinc (Mn/Zn) ratios on bacterial capsular polysaccharide (CPS) production, an important virulence determinant of many human-pathogenic bacteria, including Streptococcus pneumoniae. We show that higher Mn/Zn ratios increase CPS production via the Mn-dependent activation of the phosphoglucomutase Pgm, an enzyme that functions at the branch point between glycolysis and the CPS biosynthetic pathway. The findings provide a direct role for Mn/Zn homeostasis in the regulation of CPS expression levels and further support the ability of metal cations to act as important cellular signaling mediators in bacteria.
Topics: Bacterial Capsules; Gene Expression Regulation, Bacterial; Glycolysis; Homeostasis; Humans; Ions; Manganese; Mutation; Phosphoglucomutase; Phosphorylation; Pneumococcal Infections; Polysaccharides, Bacterial; Streptococcus pneumoniae; Virulence Factors; Zinc
PubMed: 33875543
DOI: 10.1128/JB.00602-20 -
American Journal of Human Genetics May 2019Phosphoglucomutase 1 (PGM1) encodes the metabolic enzyme that interconverts glucose-6-P and glucose-1-P. Mutations in PGM1 cause impairment in glycogen metabolism and...
Phosphoglucomutase 1 (PGM1) encodes the metabolic enzyme that interconverts glucose-6-P and glucose-1-P. Mutations in PGM1 cause impairment in glycogen metabolism and glycosylation, the latter manifesting as a congenital disorder of glycosylation (CDG). This unique metabolic defect leads to abnormal N-glycan synthesis in the endoplasmic reticulum (ER) and the Golgi apparatus (GA). On the basis of the decreased galactosylation in glycan chains, galactose was administered to individuals with PGM1-CDG and was shown to markedly reverse most disease-related laboratory abnormalities. The disease and treatment mechanisms, however, have remained largely elusive. Here, we confirm the clinical benefit of galactose supplementation in PGM1-CDG-affected individuals and obtain significant insights into the functional and biochemical regulation of glycosylation. We report here that, by using tracer-based metabolomics, we found that galactose treatment of PGM1-CDG fibroblasts metabolically re-wires their sugar metabolism, and as such replenishes the depleted levels of galactose-1-P, as well as the levels of UDP-glucose and UDP-galactose, the nucleotide sugars that are required for ER- and GA-linked glycosylation, respectively. To this end, we further show that the galactose in UDP-galactose is incorporated into mature, de novo glycans. Our results also allude to the potential of monosaccharide therapy for several other CDG.
Topics: Cells, Cultured; Cohort Studies; Congenital Disorders of Glycosylation; Fibroblasts; Galactose; Glycosylation; Humans; Phosphoglucomutase; Uridine Diphosphate Galactose; Uridine Diphosphate Glucose
PubMed: 30982613
DOI: 10.1016/j.ajhg.2019.03.003 -
Microbial Cell Factories Mar 2014Fusarium oxysporum is among the few filamentous fungi that have been reported of being able to directly ferment biomass to ethanol in a consolidated bioprocess....
BACKGROUND
Fusarium oxysporum is among the few filamentous fungi that have been reported of being able to directly ferment biomass to ethanol in a consolidated bioprocess. Understanding its metabolic pathways and their limitations can provide some insights on the genetic modifications required to enhance its growth and subsequent fermentation capability. In this study, we investigated the hypothesis reported previously that phosphoglucomutase and transaldolase are metabolic bottlenecks in the glycolysis and pentose phosphate pathway of the F. oxysporum metabolism.
RESULTS
Both enzymes were homologously overexpressed in F. oxysporum F3 using the gpdA promoter of Aspergillus nidulans for constitutive expression. Transformants were screened for their phosphoglucomutase and transaldolase genes expression levels with northern blot. The selected transformant exhibited high mRNA levels for both genes, as well as higher specific activities of the corresponding enzymes, compared to the wild type. It also displayed more than 20 and 15% higher specific growth rate upon aerobic growth on glucose and xylose, respectively, as carbon sources and 30% higher biomass to xylose yield. The determination of the relative intracellular amino and non-amino organic acid concentrations at the end of growth on glucose revealed higher abundance of most determined metabolites between 1.5- and 3-times in the recombinant strain compared to the wild type. Lower abundance of the determined metabolites of the Krebs cycle and an 68-fold more glutamate were observed at the end of the cultivation, when xylose was used as carbon source.
CONCLUSIONS
Homologous overexpression of phosphoglucomutase and transaldolase in F. oxysporum was shown to enhance the growth characteristics of the strain in both xylose and glucose in aerobic conditions. The intracellular metabolites profile indicated how the changes in the metabolome could have resulted in the observed growth characteristics.
Topics: Aspergillus nidulans; Bacterial Proteins; Biomass; Fungal Proteins; Fusarium; Glucose; Metabolic Engineering; Phosphoglucomutase; Promoter Regions, Genetic; RNA, Messenger; Transaldolase; Xylose
PubMed: 24649884
DOI: 10.1186/1475-2859-13-43 -
Molecular Genetics and Metabolism 2020Phosphoglucomutase 1 deficiency is a congenital disorder of glycosylation (CDG) with multiorgan involvement affecting carbohydrate metabolism, N-glycosylation and energy...
Phosphoglucomutase 1 deficiency is a congenital disorder of glycosylation (CDG) with multiorgan involvement affecting carbohydrate metabolism, N-glycosylation and energy production. The metabolic management consists of dietary D-galactose supplementation that ameliorates hypoglycemia, hepatic dysfunction, endocrine anomalies and growth delay. Previous studies suggest that D-galactose administration in juvenile patients leads to more significant and long-lasting effects, stressing the urge of neonatal diagnosis (0-6 months of age). Here, we detail the early clinical presentation of PGM1-CDG in eleven infantile patients, and applied the modified Beutler test for screening of PGM1-CDG in neonatal dried blood spots (DBSs). All eleven infants presented episodic hypoglycemia and elevated transaminases, along with cleft palate and growth delay (10/11), muscle involvement (8/11), neurologic involvement (5/11), cardiac defects (2/11). Standard dietary measures for suspected lactose intolerance in four patients prior to diagnosis led to worsening of hypoglycemia, hepatic failure and recurrent diarrhea, which resolved upon D-galactose supplementation. To investigate possible differences in early vs. late clinical presentation, we performed the first systematic literature review for PGM1-CDG, which highlighted respiratory and gastrointestinal symptoms as significantly more diagnosed in neonatal age. The modified Butler-test successfully identified PGM1-CDG in DBSs from seven patients, including for the first time Guthrie cards from newborn screening, confirming the possibility of future inclusion of PGM1-CDG in neonatal screening programs. In conclusion, severe infantile morbidity of PGM1-CDG due to delayed diagnosis could be prevented by raising awareness on its early presentation and by inclusion in newborn screening programs, enabling early treatments and galactose-based metabolic management.
Topics: Cleft Palate; Congenital Disorders of Glycosylation; Dried Blood Spot Testing; Female; Glycogen Storage Disease; Humans; Hypoglycemia; Infant; Infant, Newborn; Male; Neonatal Screening; Phenotype; Phosphoglucomutase
PubMed: 33342467
DOI: 10.1016/j.ymgme.2020.08.003 -
Journal of Experimental Botany Oct 2016To elucidate the starch synthesis pathway and the role of this reserve in rice pollen, we characterized mutations in the plastidic phosphoglucomutase, OspPGM, and the...
To elucidate the starch synthesis pathway and the role of this reserve in rice pollen, we characterized mutations in the plastidic phosphoglucomutase, OspPGM, and the plastidic large subunit of ADP-glucose (ADP-Glc) pyrophosphorylase, OsAGPL4 Both genes were up-regulated in maturing pollen, a stage when starch begins to accumulate. Progeny analysis of self-pollinated heterozygous lines carrying the OspPGM mutant alleles, osppgm-1 and osppgm-2, or the OsAGPL4 mutant allele, osagpl4-1, as well as reciprocal crosses between the wild type (WT) and heterozygotes revealed that loss of OspPGM or OsAGPL4 caused male sterility, with the former condition rescued by the introduction of the WT OspPGM gene. While iodine staining and transmission electron microscopy analyses of pollen grains from homozygous osppgm-1 lines produced by anther culture confirmed the starch null phenotype, pollen from homozygous osagpl4 mutant lines, osagpl4-2 and osagpl4-3, generated by the CRISPR/Cas system, accumulated small amounts of starch which were sufficient to produce viable seed. Such osagpl4 mutant pollen, however, was unable to compete against WT pollen successfully, validating the important role of this reserve in fertilization. Our results demonstrate that starch is mainly polymerized from ADP-Glc synthesized from plastidic hexose phosphates in rice pollen and that starch is an essential requirement for successful fertilization in rice.
Topics: Fertility; Glucose-1-Phosphate Adenylyltransferase; Microscopy; Mutation; Oryza; Phosphoglucomutase; Pollen; Reverse Transcriptase Polymerase Chain Reaction; Starch
PubMed: 27588462
DOI: 10.1093/jxb/erw324 -
Scientific Reports Mar 2020Human phosphoglucomutase 1 (PGM1) is an evolutionary conserved enzyme that belongs to the ubiquitous and ancient α-D-phosphohexomutases, a large enzyme superfamily with...
Human phosphoglucomutase 1 (PGM1) is an evolutionary conserved enzyme that belongs to the ubiquitous and ancient α-D-phosphohexomutases, a large enzyme superfamily with members in all three domains of life. PGM1 catalyzes the bi-directional interconversion between α-D-glucose 1-phosphate (G1P) and α-D-glucose 6-phosphate (G6P), a reaction that is essential for normal carbohydrate metabolism and also important in the cytoplasmic biosynthesis of nucleotide sugars needed for glycan biosynthesis. Clinical studies have shown that mutations in the PGM1 gene may cause PGM1 deficiency, an inborn error of metabolism previously classified as a glycogen storage disease, and PGM1 deficiency was recently also shown to be a congenital disorder of glycosylation. Here we present three crystal structures of the isoform 2 variant of PGM1, both as a free enzyme and in complex with its substrate and product. The structures show the longer N-terminal of this PGM1 variant, and the ligand complex structures reveal for the first time the detailed structural basis for both G1P substrate and G6P product recognition by human PGM1. We also show that PGM1 and the paralogous gene PGM5 are the results of a gene duplication event in a common ancestor of jawed vertebrates, and, importantly, that both PGM1 isoforms are conserved and of functional significance in all vertebrates. Our finding that PGM1 encodes two equally conserved and functionally important isoforms in the human organism should be taken into account in the evaluation of disease-related missense mutations in patients in the future.
Topics: Animals; Catalytic Domain; Cytoplasm; Glucose-6-Phosphate; Glucosephosphates; Glycogen Storage Disease; Glycosylation; Humans; Ligands; Mutation, Missense; Phosphoglucomutase; Phosphotransferases (Phosphomutases); Protein Isoforms; Vertebrates
PubMed: 32221390
DOI: 10.1038/s41598-020-62548-0