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Yuan Y, Imtiaz M, Rizwan M, Dai Z, Hossain MM, Zhang Y, Huang H, Tu S. The role and its transcriptome mechanisms of cell wall polysaccharides in vanadium detoxication of rice. JOURNAL OF HAZARDOUS MATERIALS 2022; 425:127966. [PMID: 34906871 DOI: 10.1016/j.jhazmat.2021.127966] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 11/20/2021] [Accepted: 11/29/2021] [Indexed: 06/14/2023]
Abstract
Cell wall-polysaccharides play a crucial role in heavy metals binding, and hence, contribute to heavy metal detoxication in plants. However, there is no data regarding the molecular mechanisms of vanadium (V) binding to root cell walls in plants, especially in rice (Oryza sativa L.). Taking two rice cultivars with various V tolerance as the research material, the present study investigated the effect of various V concentrations on subcellular distribution of V and revealed the regulatory mechanism of cell wall polysaccharides to V exposure. The results showed that rice roots inhibited the upward movement of V, and root cell walls accumulated 69.85-82.71% of V in roots. Furthermore, hemicellulose-1 (HC-1) in cell walls shared up to 67.72% and 66.95% of the cell-wall-bound V in tolerant and sensitive cultivars, respectively. FTIR spectroscopy demonstrated that V stress induced the remolding of cell wall polysaccharides. Under V stress, V-tolerant rice generated up to 19.3% pectin, 40.9% HC-1, and 49.34% HC-2, which were higher than V-sensitive cultivar. The genes encoding UGDH, UGE, and AXS for polysaccharide biosynthesis were higher expressed in V-tolerant rice than V-sensitive rice when exposed to V. The results could provide novel insight for phytoremediation and food security guarantees.
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Affiliation(s)
- Yuan Yuan
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Muhammad Imtiaz
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Muhammad Rizwan
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Zhihua Dai
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Md Muzammel Hossain
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Yihui Zhang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Hengliang Huang
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China
| | - Shuxin Tu
- College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China; Hubei Research Centre for Environment Pollution and Remediation, Huazhong Agricultural University, Wuhan 430070, PR China.
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2
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Zhang S, Shi Y, Huang L, Wang C, Zhao D, Ma K, Wu J, Peng D. Comparative transcriptomic analysis of rhizomes, stems, and leaves of Polygonatum odoratum (Mill.) Druce reveals candidate genes associated with polysaccharide synthesis. Gene 2020; 744:144626. [PMID: 32224272 DOI: 10.1016/j.gene.2020.144626] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 02/19/2020] [Accepted: 03/24/2020] [Indexed: 02/07/2023]
Abstract
Polygonatum odoratum (Mill.) Druce is a well-known traditional Chinese herb. Polysaccharides are major bioactive components of Polygonatum odoratum, which can improve immunity, and are used to treat rheumatic heart disease, cardiovascular disease, and diabetes. This study identified potential genes and transcription factors (TFs) that regulate polysaccharide synthesis in Polygonatum odoratum (Mill.) Druce using RNA sequencing data from leaf, stem, and rhizome tissues. 76,714 unigenes were annotated in public databases. Analysis of KEGG annotations identified 18 key enzymes responsible for polysaccharide biosynthesis and the most of the upregulated expressed unigenes were enriched in rhizome tissue compared with leaf or stem tissue. 73 TFs involved in polysaccharide synthesis were predicted. In addition, key enzyme genes were verified by quantitative real-time PCR. This study substantially enlarged the public transcriptome datasets of this species, and provided insight into detection of novel genes involved in synthesis of polysaccharides and other secondary metabolites.
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Affiliation(s)
- Shengxiang Zhang
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038
| | - Yuanyuan Shi
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038
| | - Luqi Huang
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; State Key Laboratory Breeding Base of Dao-di Herbs, National Resource Center for Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Chenkai Wang
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038
| | - Derui Zhao
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038
| | - Kelong Ma
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Clinical College of Integrated Traditional Chinese and Western Medicine, Anhui University of Chinese Medicine, China
| | - Jiawen Wu
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Key Laboratory of Xin'an Medicine, Ministry of Education, Anhui University of Chinese Medicine, Hefei 230038; Synergetic Innovation Center of Anhui Authentic Chinese Medicine Quality Improvement, Hefei 230012, China.
| | - Daiyin Peng
- Anhui University of Chinese Medicine and Anhui Academy of Chinese Medicine, Hefei 230038, China; Synergetic Innovation Center of Anhui Authentic Chinese Medicine Quality Improvement, Hefei 230012, China.
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3
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Abstract
Glycosylation is one of the most common and complex forms of posttranslational modifications of proteins in eukaryotes. Seven different protein-carbohydrate linkages have been characterized on nuclear and cytoplasmic glycoproteins, the most widespread of which is the modification of Ser/Thr residues with monosaccharides of O-linked beta-N-acetylglucosamine (O-GlcNAc). O-GlcNAc modification is concentrated in nuclear proteins. O-GlcNAc is thought to regulate protein function in a manner analogous to phosphorylation; and is implicated in the regulation of transcription, the proteasome, insulin and MAP kinase signaling, the cell cycle, and the cellular stress response. In this chapter we focus on methods for the detection of O-GlcNAc-modified proteins and discuss general techniques for the detection and subsequent analysis of other protein-carbohydrate conjugates.
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4
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DNA microarray analysis onSaccharomyces cerevisiae under high carbon dioxide concentration in fermentation process. BIOTECHNOL BIOPROC E 2005. [DOI: 10.1007/bf02989828] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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5
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Csutora P, Strassz A, Boldizsár F, Németh P, Sipos K, Aiello DP, Bedwell DM, Miseta A. Inhibition of phosphoglucomutase activity by lithium alters cellular calcium homeostasis and signaling in Saccharomyces cerevisiae. Am J Physiol Cell Physiol 2005; 289:C58-67. [PMID: 15703203 DOI: 10.1152/ajpcell.00464.2004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Phosphoglucomutase is a key enzyme of glucose metabolism that interconverts glucose-1-phosphate and glucose-6-phosphate. Loss of the major isoform of phosphoglucomutase in Saccharomyces cerevisiae results in a significant increase in the cellular glucose-1-phosphate-to-glucose-6-phosphate ratio when cells are grown in medium containing galactose as carbon source. This imbalance in glucose metabolites was recently shown to also cause a six- to ninefold increase in cellular Ca2+ accumulation. We found that Li+ inhibition of phosphoglucomutase causes a similar elevation of total cellular Ca2+ and an increase in 45Ca2+ uptake in a wild-type yeast strain grown in medium containing galactose, but not glucose, as sole carbon source. Li+ treatment also reduced the transient elevation of cytosolic Ca2+ response that is triggered by exposure to external CaCl2 or by the addition of galactose to yeast cells starved of a carbon source. Finally, we found that the Ca2+ over-accumulation induced by Li+ exposure was significantly reduced in a strain lacking the vacuolar Ca2+-ATPase Pmc1p. These observations suggest that Li+ inhibition of phosphoglucomutase results in an increased glucose-1-phosphate-to-glucose-6-phosphate ratio, which results in an accelerated rate of vacuolar Ca2+ uptake via the Ca2+-ATPase Pmc1p.
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Affiliation(s)
- Péter Csutora
- Department of Laboratory Medicine, Faculty of Medicine, Pécs University, Ifjúság u. 13, 7624 Pécs, Hungary
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6
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Aiello DP, Fu L, Miseta A, Bedwell DM. Intracellular glucose 1-phosphate and glucose 6-phosphate levels modulate Ca2+ homeostasis in Saccharomyces cerevisiae. J Biol Chem 2002; 277:45751-8. [PMID: 12351653 DOI: 10.1074/jbc.m208748200] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzyme phosphoglucomutase plays a key role in cellular metabolism by virtue of its ability to interconvert Glc-1-P and Glc-6-P. It was recently shown that a yeast strain lacking the major isoform of phosphoglucomutase (pgm2Delta) accumulates a high level of Glc-1-P and exhibits several phenotypes related to altered Ca(2+) homeostasis when d-galactose is utilized as the carbon source (Fu, L., Miseta, A., Hunton, D., Marchase, R. B., and Bedwell, D. M. (2000) J. Biol. Chem. 275, 5431-5440). These phenotypes include increased Ca(2+) uptake and accumulation and sensitivity to high environmental Ca(2+) levels. In the present study, we overproduced the enzyme UDP-Glc pyrophosphorylase to test whether the overproduction of a downstream metabolite produced from Glc-1-P can also mediate changes in Ca(2+) homeostasis. We found that overproduction of UDP-Glc did not cause any alterations in Ca(2+) uptake or accumulation. We also examined whether Glc-6-P can influence cellular Ca(2+) homeostasis. A yeast strain lacking the beta-subunit of phosphofructokinase (pfk2Delta) accumulates a high level of Glc-6-P (Huang, D., Wilson, W. A., and Roach, P. J. (1997) J. Biol. Chem. 272, 22495-22501). We found that this increase in Glc-6-P led to a 1.5-2-fold increase in total cellular Ca(2+). We also found that the pgm2Delta/pfk2Delta strain, which accumulated high levels of both Glc-6-P and Glc-1-P, no longer exhibited the Ca(2+)-related phenotypes associated with high Glc-1-P levels in the pgm2Delta mutant. These results provide strong evidence that cellular Ca(2+) homeostasis is coupled to the relative levels of Glc-6-P and Glc-1-P in yeast.
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Affiliation(s)
- David P Aiello
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, Alabama 35294-2170, USA
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7
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West CM, van der Wel H, Gaucher EA. Complex glycosylation of Skp1 in Dictyostelium: implications for the modification of other eukaryotic cytoplasmic and nuclear proteins. Glycobiology 2002; 12:17R-27R. [PMID: 11886837 DOI: 10.1093/glycob/12.2.17r] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Recently, complex O-glycosylation of the cytoplasmic/nuclear protein Skp1 has been characterized in the eukaryotic microorganism Dictyostelium. Skp1's glycosylation is mediated by the sequential action of a prolyl hydroxylase and five conventional sugar nucleotide-dependent glycosyltransferase activities that reside in the cytoplasm rather than the secretory compartment. The Skp1-HyPro GlcNAcTransferase, which adds the first sugar, appears to be related to a lineage of enzymes that originated in the prokaryotic cytoplasm and initiates mucin-type O-linked glycosylation in the lumen of the eukaryotic Golgi apparatus. GlcNAc is extended by a bifunctional glycosyltransferase that mediates the ordered addition of beta1,3-linked Gal and alpha1,2-linked Fuc. The architecture of this enzyme resembles that of certain two-domain prokaryotic glycosyltransferases. The catalytic domains are related to those of a large family of prokaryotic and eukaryotic, cytoplasmic, membrane-bound, inverting glycosyltransferases that modify glycolipids and polysaccharides prior to their translocation across membranes toward the secretory pathway or the cell exterior. The existence of these enzymes in the eukaryotic cytoplasm away from membranes and their ability to modify protein acceptors expose a new set of cytoplasmic and nuclear proteins to potential prolyl hydroxylation and complex O-linked glycosylation.
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Affiliation(s)
- Christopher M West
- Department of Anatomy and Cell Biology, 1600 SW Archer Road, University of Florida College of Medicine, Gainesville, FL 32610-0235, USA
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8
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Wyroba E, Satir BH. A comparative hybridization analysis of yeast DNA with Paramecium parafusin- and different phosphoglucomutase-specific probes. Biochem Cell Biol 2000. [DOI: 10.1139/o00-080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Molecular probes designed for the parafusin (PFUS), the Paramecium exocytic-sensitive phospho glyco protein, gave distinct hybridization patterns in Saccharomyces cerevisiae genomic DNA when compared with different phosphoglucomutase specific probes. These include two probes identical to segments of yeast phosphoglucomutase (PGM) genes 1 and 2. Neither of the PGM probes revealed the 7.4 and 5.9 kb fragments in Bgl II-cut yeast DNA digest detected with the 1.6 kb cloned PFUS cDNA and oligonucleotide constructed to the PFUS region (insertion 3 I-3) not found in other species. PCR amplification with PFUS-specific primers generated yeast DNA-species of the predicted molecular size which hybridized to the I-3 probe. A search of the yeast genome database produced an unassigned nucleotide sequence that showed 55% identity to parafusin gene and 37% identity to PGM2 (the major isoform of yeast phosphoglucomutase) within the amplified region.Key words: parafusin, phosphoglucomutase, yeast, hybridization, PCR.
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9
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Gasch AP, Spellman PT, Kao CM, Carmel-Harel O, Eisen MB, Storz G, Botstein D, Brown PO. Genomic expression programs in the response of yeast cells to environmental changes. Mol Biol Cell 2000; 11:4241-57. [PMID: 11102521 PMCID: PMC15070 DOI: 10.1091/mbc.11.12.4241] [Citation(s) in RCA: 3367] [Impact Index Per Article: 140.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
We explored genomic expression patterns in the yeast Saccharomyces cerevisiae responding to diverse environmental transitions. DNA microarrays were used to measure changes in transcript levels over time for almost every yeast gene, as cells responded to temperature shocks, hydrogen peroxide, the superoxide-generating drug menadione, the sulfhydryl-oxidizing agent diamide, the disulfide-reducing agent dithiothreitol, hyper- and hypo-osmotic shock, amino acid starvation, nitrogen source depletion, and progression into stationary phase. A large set of genes (approximately 900) showed a similar drastic response to almost all of these environmental changes. Additional features of the genomic responses were specialized for specific conditions. Promoter analysis and subsequent characterization of the responses of mutant strains implicated the transcription factors Yap1p, as well as Msn2p and Msn4p, in mediating specific features of the transcriptional response, while the identification of novel sequence elements provided clues to novel regulators. Physiological themes in the genomic responses to specific environmental stresses provided insights into the effects of those stresses on the cell.
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Affiliation(s)
- A P Gasch
- Department of Biochemistry, Stanford University School of Medicine, Stanford, CA 94305-5428, USA
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10
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Teng-umnuay P, Morris HR, Dell A, Panico M, Paxton T, West CM. The cytoplasmic F-box binding protein SKP1 contains a novel pentasaccharide linked to hydroxyproline in Dictyostelium. J Biol Chem 1998; 273:18242-9. [PMID: 9660787 DOI: 10.1074/jbc.273.29.18242] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
SKP1 is involved in the ubiquitination of certain cell cycle and nutritional regulatory proteins for rapid turnover. SKP1 from Dictyostelium has been known to be modified by an oligosaccharide containing Fuc and Gal, which is unusual for a cytoplasmic or nuclear protein. To establish how it is glycosylated, SKP1 labeled with [3H]Fuc was purified to homogeneity and digested with endo-Lys-C. A single radioactive peptide was found after two-dimensional high performance liquid chromatography. Analysis in a quadrupole time-of-flight mass spectrometer revealed a predominant ion with a novel mass. Tandem mass spectrometry analysis yielded a set of daughter ions which identified the peptide and showed that it was modified at Pro-143. A second series of daughter ions showed that Pro-143 was hydroxylated and derivatized with a potentially linear pentasaccharide, Hex-->Hex-->Fuc-->Hex-->HexNAc-->(HyPro). The attachment site was confirmed by Edman degradation. Gas chromatography-mass spectrometry analysis of trimethylsilyl-derivatives of overexpressed SKP1 after methanolysis showed the HexNAc to be GlcNAc. Exoglycosidase digestions of the glycopeptide from normal SKP1 and from a fucosylation mutant, followed by matrix-assisted laser desorption time-of-flight mass spectrometry analysis, showed that the sugar chain consisted of D-Galpalpha1-->6-D-Galpalpha1-->L-Fucpalpha1-->2-D- Galpbeta1--> 3GlcNAc. Matrix-assisted laser-desorption time-of-flight mass spectrometry analysis of all SKP1 peptides resolved by reversed phase-high performance liquid chromatography showed that SKP1 was only partially hydroxylated at Pro-143 and that all hydroxylated SKP1 was completely glycosylated. Thus SKP1 is variably modified by an unusual linear pentasaccharide, suggesting the localization of a novel glycosylation pathway in the cytoplasm.
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Affiliation(s)
- P Teng-umnuay
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville, Florida 32610-0235, USA
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11
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Zwartjes RE, West H, Hattar S, Ren X, Noel F, Nuñez-Regueiro M, MacPhee K, Homayouni R, Crow MT, Byrne JH, Eskin A. Identification of specific mRNAs affected by treatments producing long-term facilitation in Aplysia. Learn Mem 1998; 4:478-95. [PMID: 10701873 DOI: 10.1101/lm.4.6.478] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Neural correlates of long-term sensitization of defensive withdrawal reflexes in Aplysia occur in sensory neurons in the pleural ganglia and can be mimicked by exposure of these neurons to serotonin (5-HT). Studies using inhibitors indicate that transcription is necessary for production of long-term facilitation by 5-HT. Several mRNAs that change in response to 5-HT have been identified, but the molecular events responsible for long-term facilitation have not yet been fully described. To detect additional changes in mRNAs, we investigated the effects of 5-HT (1.5 hr) on levels of mRNA in pleural-pedal ganglia using in vitro translation. Four mRNAs were affected by 5-HT, three of which were identified as calmodulin (CaM), phosphoglycerate kinase (PGK), and a novel gene product (protein 3). Using RNase protection assays, we found that 5-HT increased all three mRNAs in the pleural sensory neurons. CaM and protein 3 mRNAs were also increased in the sensory neurons by sensitization training. Furthermore, stimulation of peripheral nerves of pleural-pedal ganglia, an in vitro analog of sensitization training, increased the incorporation of labeled amino acids into CaM, PGK, and protein 3. These results indicate that increases in CaM, PGK, and protein 3 are part of the early response of sensory neurons to stimuli that produce long-term facilitation, and that CaM and protein 3 could have a role in the generation of long-term sensitization.
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Affiliation(s)
- R E Zwartjes
- Department of Biochemical and Biophysical Sciences, University of Houston, Texas 77204-5934, USA
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12
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Chilcoat ND, Turkewitz AP. In vivo analysis of the major exocytosis-sensitive phosphoprotein in Tetrahymena. J Cell Biol 1997; 139:1197-207. [PMID: 9382866 PMCID: PMC2140215 DOI: 10.1083/jcb.139.5.1197] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/1997] [Revised: 09/22/1997] [Indexed: 02/05/2023] Open
Abstract
Phosphoglucomutase (PGM) is a ubiquitous highly conserved enzyme involved in carbohydrate metabolism. A number of recently discovered PGM-like proteins in a variety of organisms have been proposed to function in processes other than metabolism. In addition, sequence analysis suggests that several of these may lack PGM enzymatic activity. The best studied PGM-like protein is parafusin, a major phosphoprotein in the ciliate Paramecium tetraurelia that undergoes rapid and massive dephosphorylation when cells undergo synchronous exocytosis of their dense-core secretory granules. Indirect genetic and biochemical evidence also supports a role in regulated exocytotic membrane fusion. To examine this matter directly, we have identified and cloned the parafusin homologue in Tetrahymena thermophila, a ciliate in which protein function can be studied in vivo. The unique T. thermophila gene, called PGM1, encodes a protein that is closely related to parafusin by sequence and by characteristic post-translational modifications. Comparison of deduced protein sequences, taking advantage of the known atomic structure of rabbit muscle PGM, suggests that both ciliate enzymes and all other PGM-like proteins have PGM activity. We evaluated the activity and function of PGM1 through gene disruption. Surprisingly, DeltaPGM1 cells displayed no detectable defect in exocytosis, but showed a dramatic decrease in PGM activity. Both our results, and reinterpretation of previous data, suggest that any potential role for PGM-like proteins in regulated exocytosis is unlikely to precede membrane fusion.
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Affiliation(s)
- N D Chilcoat
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois 60637, USA
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13
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Ortner S, Binder M, Scheiner O, Wiedermann G, Duchêne M. Molecular and biochemical characterization of phosphoglucomutases from Entamoeba histolytica and Entamoeba dispar. Mol Biochem Parasitol 1997; 90:121-9. [PMID: 9497037 DOI: 10.1016/s0166-6851(97)00147-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Entamoeba histolytica and Entamoeba dispar have only recently been defined as two separate species. E. histolytica, the pathogenic species, is the microorganism causing invasive intestinal amoebiasis and/or liver abscess, while the morphologically similar E. dispar is nonpathogenic and noninvasive. The gold standard for the distinction of the two species has been the isoenzyme electrophoresis of phosphoglucomutases (EC 5.4.2.2) and hexokinases (EC 2.7.1.1), but there had also been a controversy about the possibility of a conversion of isoenzyme patterns. In this study, we cloned the phosphoglucomutase (PGM) cDNAs from the pathogenic and the nonpathogenic species. The deduced amino acid sequences were only 2.4% different. The cDNAs were expressed in Escherichia coli under the control of a T7 RNA polymerase promoter. The recombinant polypeptides displayed strong phosphoglucomutase activity, each of the recombinant enzymes comigrated with its natural counterpart from E. histolytica and E. dispar in the starch gel electrophoresis. Our results give a biochemical interpretation of the PGM isoenzyme pattern and support the clear distinction between the two species.
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Affiliation(s)
- S Ortner
- Institute for Specific Prophylaxis and Tropical Medicine, University of Vienna, Austria
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14
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Lalioti VS, Ballesta JP, Fragoulis EG. Purification and characterization of a novel poly(U), poly(C) ribonuclease from Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA 1997; 1342:62-72. [PMID: 9366271 DOI: 10.1016/s0167-4838(97)00078-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A new ribonuclease from Saccharomyces cerevisiae, specific for poly(U) and poly(C) substrate, was purified near to homogeneity by successive fractionation with DEAE-Sepharose, Heparin-Sepharose and CM-Sepharose chromatography. The purified molecule detected by SDS/polyacrylimide gel electrophoresis has a molecular mass of 29 kDa. The optimum pH for the enzyme activity is 5.5-7 and its isoelectric point is 7.5. The purified enzyme was able to degrade 26S, 18S and 5S rRNAs as well as mRNA obtained from in vitro transcription. No catalytic activity was observed when the RNase was incubated with tRNA and double stranded substrate. Our findings suggest that this novel RNase may play an important role in the processing of RNA in Saccharomyces cerevisiae.
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Affiliation(s)
- V S Lalioti
- University of Athens, Department of Biochemistry and Molecular Biology, Greece
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15
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Daran JM, Bell W, François J. Physiological and morphological effects of genetic alterations leading to a reduced synthesis of UDP-glucose in Saccharomyces cerevisiae. FEMS Microbiol Lett 1997; 153:89-96. [PMID: 9252577 DOI: 10.1111/j.1574-6968.1997.tb10468.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Yeast cells lacking UDP-Glc pyrophosphorylase (UGPase) encoded by UGPI are not viable. Two strategies were developed to drastically reduce the intracellular concentration of UDP-Glc in order to study the consequences of this metabolic engineering on physiology and morphology. Firstly, UGP1 was placed under the strongly regulatable THI4 promoter. This resulted in a 95% reduction of UGPase activity in the presence of thiamine. The phenotypic effects of this reduction were slightly stronger than those of glucose on the GALI0/CYC1-UGP1 gene fusion [Daran et al. (1995) Eur. J. Biochem. 230, 520-530]. A further reduction of flux towards UDP-Glc was achieved by deletion of the two phosphoglucomutase genes in the ugp1 conditional strain. The growth of this new mutant strain was hardly affected, while it was extremely sensitive to cell wall interfering drugs. Surprisingly, UDP-Glc levels were reduced only by 5-fold, causing a proportional decrease in both glycogen and beta-glucans. Taken altogether, these results indicate that a few percent of enzymatic activities leading to the formation of UDP-Glc appears sufficient to provide the UDP-Glc demands required for cell viability, and that the loss of function of UGP1 is lethal mainly because of the inability of yeast cells to properly form the cell wall.
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Affiliation(s)
- J M Daran
- Centre de Bioingenierie Gilberi Durand, UMR-CNRS 5504, Laboratoire associé INRA, Toulouse, France
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16
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Affiliation(s)
- B G Winchester
- Division of Biochemistry and Genetics, Institute of Child Health, London, United Kingdom
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17
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Fu L, Bounelis P, Dey N, Browne BL, Marchase RB, Bedwell DM. The posttranslational modification of phosphoglucomutase is regulated by galactose induction and glucose repression in Saccharomyces cerevisiae. J Bacteriol 1995; 177:3087-94. [PMID: 7768805 PMCID: PMC176997 DOI: 10.1128/jb.177.11.3087-3094.1995] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The enzyme phosphoglucomutase functions at a key point in carbohydrate metabolism. In this paper, we show that the synthesis of the major isoform of yeast phosphoglucomutase, encoded by the GAL5 (PGM2) gene, is regulated in a manner that is distinct from that previously described for other enzymes involved in galactose metabolism in the yeast Saccharomyces cerevisiae. Accumulation of this isoform increased four- to sixfold when the culture experienced either glucose depletion or heat shock. However, heat shock induction did not occur unless the cells were under glucose repression. This nonadditive increase in expression suggests that the regulatory mechanisms controlling the heat shock induction and glucose repression of the GAL5 gene are functionally related. We previously demonstrated that phosphoglucomutase is modified by a posttranslational Glc-phosphorylation reaction. We now show that this posttranslational modification, like phosphoglucomutase expression itself, is also regulated by galactose induction and glucose repression. Finally, no evidence was found to indicate that the Glc-phosphorylation of phosphoglucomutase alters its enzymatic activity under the conditions examined.
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Affiliation(s)
- L Fu
- Department of Microbiology, University of Alabama at Birmingham 35294, USA
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Kozarov E, van der Wel H, Field M, Gritzali M, Brown RD, West CM. Characterization of FP21, a cytosolic glycoprotein from Dictyostelium. J Biol Chem 1995; 270:3022-30. [PMID: 7852383 DOI: 10.1074/jbc.270.7.3022] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
FP21 is a glycoprotein which, when tracked by radioactivity in its fucosyl moiety, was previously detected in the cytosol of Dictyostelium cells after cell fractionation. This compartmentalization is confirmed by SDS-polyacrylamide gel electrophoresis/Western blotting of cell fractions using three different antibodies. Although a substantial fraction of FP21 is also detected in the particulate fraction using these new antibodies, particulate FP21 is released by disrupting protein-protein interactions, but not membrane disruption. Since purified FP21 is susceptible to aggregation, and purified nuclei do not contain FP21, particulate FP21 is also part of the cytosol. Additional compositional and structural information provides strong evidence that FP21 does not at any time traverse the rough endoplasmic reticulum. First, cDNAs spanning the entire coding region of the FP21 gene predict no hydrophobic motifs expected to promote membrane insertion, but do predict an NH2-terminal coiled coil domain which could explain aggregation. Second, monosaccharide composition analysis of the predominant glycoform of FP21 yields 2 mol of galactose, 1 mol of xylose, and 1 mol of fucose/mol of polypeptide; FP21 from a fucosylation-defective mutant contains 1 additional mol of xylose in place of fucose. Thus the N-glycosylation sequon present in FP21 is not utilized by oligosaccharyl transferase, which resides in the rough endoplasmic reticulum. These findings indicate that nascent FP21 remains in the cytosol after synthesis and is therefore glycosylated by unusual cytosolic xylosyl-, galactosyl-, and fucosyltransferases.
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Affiliation(s)
- E Kozarov
- Department of Anatomy and Cell Biology, College of Medicine, University of Florida, Gainesville 32610-0235
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Dey NB, Bounelis P, Fritz TA, Bedwell DM, Marchase RB. The glycosylation of phosphoglucomutase is modulated by carbon source and heat shock in Saccharomyces cerevisiae. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)47136-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Boles E, Liebetrau W, Hofmann M, Zimmermann FK. A family of hexosephosphate mutases in Saccharomyces cerevisiae. EUROPEAN JOURNAL OF BIOCHEMISTRY 1994; 220:83-96. [PMID: 8119301 DOI: 10.1111/j.1432-1033.1994.tb18601.x] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The Saccharomyces cerevisiae PGM1 and PGM2 genes encoding two phosphoglucomutase isoenzymes have been isolated and sequenced. The derived protein sequences are closely related to one another and show distinct sequence similarities to the human and rabbit phosphoglucomutases, especially in the region supposed to constitute the active site. PGM1 and PGM2 are located on chromosomes XI and XIII, respectively, just upstream of the known genes YPK1 and YKR2 coding for a pair of closely related putative protein kinases. These observations suggest that an extended region of DNA arose by the process of gene duplication. Cells deleted for both, PGM1 and PGM2, could not grow on galactose. No residual phosphoglucomutase activity could be measured in crude extracts or in permeabilized cells of pgm1/2 double mutants. Unexpectedly, growth with glucose was not impaired and the mutant cells were still able to accumulate trehalose and glycogen, although at a reduced level. Two further genes could be isolated and characterized which when over-expressed on a multi-copy plasmid could restore growth on galactose of the pgm1/2 double deletion mutant. Multi-copy complementation was due to a sharply increased level of phosphoglucomutase activity. Partial sequencing and characterization of the two genes revealed one of them to be SEC53 encoding phosphomannomutase. No extended sequence similarities could be found in the databases for the second gene. However, part of the derived amino acid sequence contained a region of high similarity to the active-site consensus sequence of hexosephosphate mutases from different organism. Further investigations suggest that a complex network of mutases exist in yeast which interact and can partially substitute for each other.
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Affiliation(s)
- E Boles
- Institut für Mikrobiologie, Technische Hochschule Darmstadt, Germany
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