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Phosphoglycerate Kinase (phosphoglycerate + kinase)

Distribution by Scientific Domains

Medical Sciences	42%
Life Sciences	42%

Selected Abstracts

Phosphoglycerate kinase deficiency in two brothers with McArdle-like clinical symptoms

EUROPEAN JOURNAL OF NEUROLOGY, Issue 1 2000
J. Aasly
Phosphoglycerate kinase (PGK) catalyses the transfer of the acylphosphate group of 1,3-diphosphoglycerate to ADP with formation of 3-phosphoglycerate and ATP in the terminal stage of the glycolytic pathway. Two young brothers are presented who both experienced muscle pain, cramps and stiffness shortly after beginning heavy exercise. After these episodes they noticed that the urine was dark brown, indicating rhabdomyolysis and myoglobinuria. The neurological examinations were without remarks. There was no lactate increase in the ischaemic forearm exercise test. Both had very low PGK levels in muscle, erythrocytes, leukocytes and fibroblasts. This is the first family with more than one affected case of PGK deficiency and exercise-induced stiffness, myalgia and rhabdomyolysis. The clinical manifestations may resemble myophosphorylase deficiency (McArdle's disease: glycogenosis Type V) and muscle phosphofructokinase deficiency (Tarui's disease: glycogenosis Type VII). PGK deficiency is inherited as an X-linked trait and may show other features such as mental retardation and/or haemolytic anaemia. [source]

Phosphoglycerate kinase 1 a promoting enzyme for peritoneal dissemination in gastric cancer,

INTERNATIONAL JOURNAL OF CANCER, Issue 6 2010
Derek Zieker
Abstract Peritoneal carcinomatosis is a frequent finding in gastric cancer associated with a poor prognosis. The features that enable gastric tumors to disseminate are poorly understood until now. Previously, we showed elevated mRNA levels of phosphoglycerate kinase 1 (PGK1), an adenosine triphosphate-generating enzyme in the glycolytic pathway, the chemokine receptor 4 (CXCR4), the corresponding chemokine ligand 12 (CXCL12) and ,-catenin in specimens from gastric cancer patients with peritoneal carcinomatosis. In this study, the influence of PGK1 on CXCR4 and ,-catenin was assessed as well as the invasiveness of PGK1 overexpressing cancer cells. In this current study, we found that PGK1 regulates the expression of CXCR4 and ,-catenin at the mRNA and protein levels. On the other hand, CXCR4 regulates the expression of PGK1. Plasmid-mediated overexpression of PGK1 dramatically increased the invasiveness of gastric cancer cells. Interestingly, inhibition of CXCR4 in cells overexpressing PGK1 produced only a moderate reduction of invasiveness suggesting that, PGK1 itself has a critical role in tumor invasiveness. Immunohistochemistry in specimens from diffuse gastric cancer patients also revealed an overexpression of PGK1 in patients with development of peritoneal carcinomatosis. Therefore, PGK1 may be a crucial enzyme in peritoneal dissemination. Together these findings suggest that the enhanced expression of PGK1 and its signaling targets CXCR4 and ,-catenin in gastric cancer cells promote peritoneal carcinomatosis. Thus, PGK1 may serve as prognostic marker and/or be a potential therapeutic target to prevent dissemination of gastric carcinoma cells into the peritoneum. [source]

Heterologous expression of a Clostridium minicellulosome in Saccharomyces cerevisiae

FEMS YEAST RESEARCH, Issue 8 2009
Mariska Lilly
Abstract The yeast Saccharomyces cerevisiae was genetically modified to assemble a minicellulosome on its cell surface by heterologous expression of a chimeric scaffoldin protein from Clostridium cellulolyticum under the regulation of the phosphoglycerate kinase 1 (PGK1) promoter and terminator regulatory elements, together with the ,-xylanase 2 secretion signal of Trichoderma reesei and cell wall protein 2 (Cwp2) of S. cerevisiae. Fluorescent microscopy and Far Western blot analysis confirmed that the Scaf3p is targeted to the yeast cell surface and that the Clostridium thermocellum cohesin domain is functional in yeast. Similarly, functionality of the C. thermocellum dockerin domain in yeast is shown by binding to the Scaf3 protein in Far Western blot analysis. Phenotypic evidence for cohesin,dockerin interaction was also established with the detection of a twofold increase in tethered endoglucanase enzyme activity in S. cerevisiae cells expressing the Scaf3 protein compared with the parent strain. This study highlights the feasibility to future design of enhanced cellulolytic strains of S. cerevisiae through emulation of the cellulosome concept. Potentially, Scaf3p-armed yeast could also be developed into an alternative cell surface display strategy with various tailor-made applications. [source]

The epigenetic calnexin-independent state is induced in response to environmental changes

FEMS YEAST RESEARCH, Issue 8 2009
Renée Guérin
Abstract Yeasts have evolved numerous responsive pathways to survive in fluctuating and stressful environments. The endoplasmic reticulum (ER) is sensitive to adverse conditions, which are detected by response pathways to ensure correct protein folding. Calnexin is an ER transmembrane chaperone acting in both quality control of folding and response to persistent stress. Calnexin is a key protein required for viability in certain organisms such as mammals and the fission yeast Schizosaccharomyces pombe. Nevertheless, S. pombe calnexin-independent (Cin) cells were obtained after transient expression of a particular calnexin mutant. The Cin state is dominant, is stably propagated by an epigenetic mechanism and segregates in a non-Mendelian fashion to the meiotic progeny. The nucleolar protein Cif1p was identified as an inducer of the Cin state in a previous genetic screen. Here, we report the identification of novel inducers isolated in an overexpression genetic screen: pyruvate kinase (Pyk1p) and phosphoglycerate kinase (Pgk1p). Addition of pyruvate, the end product of pyruvate kinase and glycolysis, also induced calnexin independence in a dose-dependent manner. Remarkably, growth in respiration media or cold temperatures induced the appearance of Cin cells at high frequencies. Taken together, our results indicate that the Cin state can be triggered by extracellular changes, suggesting that this state represents an epigenetic adaptative response to environmental modifications. [source]

MSY2 and polypyrimidine tract binding protein 2 stabilize mRNAs in the mammalian testis

INTERNATIONAL JOURNAL OF ANDROLOGY, Issue 5 2008
Mingang Xu
Summary MSY2 is a highly conserved and abundant DNA/RNA-binding protein that functions as a global stabilizer/translational suppressor of mRNAs in male germ cells. The polypyrimidine tract binding protein, PTBP2, is an RNA-binding protein that splices nuclear transcripts and stabilizes specific mRNAs in the cytoplasm. The mechanisms whereby MSY2 selects and stabilizes a large group of male germ cell mRNAs and PTBP2 stabilizes specific mRNAs such as the phosphoglycerate kinase 2 mRNA in the testis and in transfected cells will be discussed. [source]

Phosphoglycerate kinase 1 a promoting enzyme for peritoneal dissemination in gastric cancer,

Proteomic Analysis Demonstrates Adolescent Vulnerability to Lasting Hippocampal Changes Following Chronic Alcohol Consumption

ALCOHOLISM, Issue 1 2009
Garth A. Hargreaves
Background:, Excessive teenage alcohol consumption is of great concern because alcohol may adversely alter the developmental trajectory of the brain. The aim of the present study was to assess whether chronic intermittent alcohol intake during the adolescent period alters hippocampal protein expression to a greater extent than during adulthood. Methods:, Adolescent [postnatal day (PND) 27] and adult (PND 55) male Wistar rats were given 8 hours daily access to beer (4.44% ethanol v/v) in addition to ad libitum food and water for 4 weeks. From a large subject pool, subgroups of adolescent and adult rats were selected that displayed equivalent alcohol intake (average of 6.1 g/kg/day ethanol). The 4 weeks of alcohol access were followed by a 2-week alcohol-free washout period after which the hippocampus was analyzed using 2-DE proteomics. Results:, Beer consumption by the adult group resulted in modest hippocampal changes relative to alcohol naïve adult controls. The only changes observed were an up-regulation of citrate synthase (a precursor to the Krebs cycle) and fatty acid binding protein (which facilitates fatty acid metabolism). In contrast, adolescent rats consuming alcohol showed more widespread hippocampal changes relative to adolescent controls. These included an increase in cytoskeletal protein T-complex protein 1 subunit epsilon (TCP-1) and a decrease in the expression of 10 other proteins, including glyceraldehyde-3-phosphate dehydrogenase (GAPDH), triose phosphate isomerise, alpha-enolase, and phosphoglycerate kinase 1 (all involved in glycolysis); glutamate dehydrogenase 1 (an important regulator of glutamate); methylmalonate-semialdehyde dehydrogenase (involved in aldehyde detoxification); ubiquitin carboxyl-terminal hydrolase isozyme L1 (a regulator of protein degradation); and synapsin 2 (involved in synaptogenesis and neurotransmitter release). Conclusions:, These results suggest the adolescent hippocampus is more vulnerable to lasting proteomic changes following repeated alcohol exposure. The proteins most affected include those related to glycolysis, glutamate metabolism, neurodegeneration, synaptic function, and cytoskeletal structure. [source]

Aberrant protein expression is associated with decreased developmental potential in porcine cumulus,oocyte complexes

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 1 2010
Melissa Paczkowski
Oocyte developmental competence is progressively obtained during pubertal development in females. Poor developmental potential in oocytes derived from prepubertal females suggests that essential processes required for oocyte development have not been fulfilled. The objective of this experiment was to analyze the protein profiles of porcine cumulus,oocyte complexes (COC) derived from cyclic and prepubertal females to identify alterations in protein abundance that correlate with developmental potential. COC complexes, aspirated from prepubertal and cyclic ovaries, were pooled into three replicates of 400 COCs each per treatment in ,100,µl SOF-HEPES medium. Protein samples were extracted and analyzed by two-dimensional differential in gel electrophoresis (2D-DIGE). Over 1,600 proteins were resolved on each of the three replicate gels. Sixteen protein spots were identified by mass spectrometry, representing 14 unique, differentially expressed proteins (volume ratio greater than 1.3). Glutathione- S -transferase and pyruvate kinase 3 were more abundant in COCs derived from cyclic females, whereas soluble epoxide hydrolase and transferrin were more abundant in prepubertal derived COCs. Abundance of several glycolytic enzymes (enolase 1, pyruvate kinase 3, and phosphoglycerate kinase) was increased in COCs derived from cyclic females, suggesting glucose metabolism is decreased in prepubertal derived COCs. We conclude that the abundance of proteins involved in metabolism and oxidative stress regulation is significantly altered in prepubertal derived COCs and may play a role in the mechanisms resulting in developmental competence. Mol. Reprod. Dev. 77: 51,58, 2010. © 2009 Wiley-Liss, Inc. [source]

Stable transgene expression in human embryonic stem cells after simple chemical transfection

MOLECULAR REPRODUCTION & DEVELOPMENT, Issue 6 2009
Jun Liu
In this study we used plasmid-based vectors to investigate the transcriptional activities of three commonly used promoters in transient and stable transfection of MEL-1, a human embryonic stem (ES) cell line, using ExGen500, Fugene HD, and Lipofectamine. We demonstrated that cytomegalovirus (CMV), phosphoglycerate kinase (PGK) and human elongation factor-1, (EF1,) promoters all resulted in robust activity of a reporter gene in MEL-1 ES cell transient transfections regardless of the transfection reagent. Stable transfection outcomes varied, depending on the promoter and the transfection reagent used in the study. The phenomenon of transgene silencing was observed, most notably with the CMV vector, with which no positive stably transfected clones were obtained. Of the methods used in the study, Fugene HD resulted in the highest stable transfection rate, estimated by antibiotic selection, with plasmids containing genes under the control of the EF1, or PGK promoters. Stably transfected cells maintained typical hES cell morphology, with immunostaining exhibiting expression of the hES cell markers: Oct4, SSEA4, Tra-1-60, and Tra-1-81. Further, embryoid bodies formed by suspension culture retained reporter gene expression. Following injection into immunodeficient mice, the transfected cell lines showed robust formation of teratomas with cell types representative of the three germ layers. Mol. Reprod. Dev. 76: 580,586, 2009. © 2008 Wiley-Liss, Inc. [source]

Proteomic analysis of the response of an acidophilic strain of Chlamydomonas sp. (Chlorophyta) to natural metal-rich water

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 10 2010
Cristina Cid
Abstract A proteomic approach including 2-DE and MALDI-TOF analysis has been developed to identify the soluble proteins of the unicellular photosynthetic algae Chlamydomonas sp. isolated from an extreme acidic environment, Río Tinto (southwest Spain). We have analyzed the soluble proteome obtained from whole cells growing on metal-rich natural acidic water from the river in comparison with the same strain growing in artificial BG-11 media. The most drastic effect was the decrease in the abundance of the ribulose-1,5-biphosphate carboxylase as well as other enzymes related to photosynthesis. However, phytochrome B, phosphoribulokinase, and phosphoglycerate kinase were upregulated when cells were grown in metal-rich acidic water. Besides, increased accumulation of two Hsps, Hsp70 and Hsp90 as well as other stress-related enzymes were also found in the cells growing in natural acidic water. These results suggest that naturally occurring metal-rich water induces a stress response in acidophilic Chlamydomonas forcing algal cells to reorganize their metabolic pathways as an adaptive response to these environmental conditions. [source]

Banana (Musa spp.) as a model to study the meristem proteome: Acclimation to osmotic stress

PROTEINS: STRUCTURE, FUNCTION AND BIOINFORMATICS, Issue 1 2007
Sebastien C. Carpentier
Abstract Banana (Musa spp.) multiple shoot meristems are an excellent model to study the meristem proteome. Using a 2-DE protocol developed for small amounts of tissue and MS-based cross species polypeptide identification, we have revealed the meristem proteome and investigated the influence of sucrose-mediated osmotic stress in a dehydration-tolerant variety. Proteins that were significantly up- or down-regulated due to the high-sucrose treatment were classified using non-parametric univariate statistics. Our results suggest that the maintenance of an osmoprotective intracellular sucrose concentration, the enhanced expression of particular genes of the energy-conserving glycolysis and the conservation of the cell wall integrity are essential to maintain homeostasis, to acclimate and to survive dehydration. By comparing the dehydration-tolerant variety with a dehydration-sensitive variety, we were able to distinguish several genotype-specific proteins (isoforms), and could associate the dehydration-tolerant variety with proteins involved in energy metabolism (e.g., phosphoglycerate kinase, phosphoglucomutase, UDP-glucose pyrophosphorylase) and proteins that are associated with stress adaptation (e.g., OSR40-like protein, abscisic stress ripening protein-like protein). This work shows that proteome analysis can be used successfully to perform quantitative difference analysis and to characterize genetic variations in a recalcitrant crop. [source]

Identification of immunodominant autoantigens in rat autoimmune orchitis

THE JOURNAL OF PATHOLOGY, Issue 2 2005
Monika Fijak
Abstract Infection and inflammation of the genital tract are amongst the leading causes of male infertility. Experimental autoimmune orchitis (EAO) in the rat serves as a model for the investigation of inflammatory testicular impairment. In this study, experiments were conducted to identify the molecules that are responsible for eliciting the autoimmune attack on the testis. EAO was induced in in-bred Wistar rats by active immunization with testis homogenates (EAO group I). Development of disease was observed using histological techniques and a new non-invasive three-dimensional (3D) imaging technology for in vivo monitoring, termed flat-panel volumetric computed tomography (fpvCT). Examination of control and EAO testes demonstrated the superior image quality of high-resolution fpvCT. A proteomics approach using 2D SDS-PAGE and immunoblotting analysis with EAO sera identified 12 spots. Seven were subsequently identified by mass spectrometry as heat shock proteins 60 (Hsp60) and 70 (Hsp70), disulphide isomerase ER-60, alpha-1-anti-trypsin, heterogeneous nuclear ribonucleoprotein H1 (hnRNP H1), sperm outer dense fibre major protein 2 (ODF-2), and phosphoglycerate kinase 1. Hsp70, ODF-2, hnRNP H1, and ER-60 were identified by all EAO sera studied. To test the capacity of the identified proteins to elicit testicular autoimmune disease, recombinant proteins were used either individually or in combination to immunize rats (EAO group II). In all groups, the incidence of EAO was 25%. Inflammatory-type (ED1+) and resident (ED2+) macrophages, lymphocytes (CD45RA+), and dendritic cells (Ox-62+) were strongly increased in EAO group II animals, comparable to the testes of EAO I rats. Pre-immunization with a low dose of recombinant Hsp 70, hnRNP H1 or ODF-2 before induction of EAO with testis homogenate significantly delayed the onset of EAO but could not prevent disease. The identification of testicular autoantigens will allow a better understanding of disease pathogenesis and could provide a basis for the development of novel therapies for inflammation-based male infertility. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd. [source]

The role of inorganic phosphate in the development of freezing tolerance and the acclimatization of photosynthesis to low temperature is revealed by the pho mutants of Arabidopsis thaliana

THE PLANT JOURNAL, Issue 3 2000
Vaughan Hurry
Summary Low temperature inhibits sucrose synthesis, leading to a phosphate-limitation of photosynthesis. We have used the Arabidopsis pho1-2 and pho2-1 mutants with decreased and increased shoot phosphate, respectively, to investigate whether low phosphate triggers cold acclimatization of photosynthetic carbon metabolism. Wild-type Arabidopsis, pho1-2 and pho2-1 were grown at 23°C and transferred to 5°C to investigate acclimatization in pre-existing leaves and in new leaves developing at 5°C. The development of frost tolerance and the accumulation of proline and sugars was unaltered or improved in pho1-2, and impaired in pho2-1. Sucrose phosphate synthase and cytoplasmic fructose-1,6-bisphosphatase activity and protein increase after transfer to 5°C. This increase was accentuated in pho1-2 and attenuated in pho2-1. RBCS and LHCB2 transcript levels decrease in pre-formed wild-type leaves after transfer to 5°C and recover in new leaves that develop at 5°C. The initial decrease was attenuated in pho1-2, and accentuated in pho2-1, where the recovery in new leaves was also suppressed. Rubisco activity increased in wild-type leaves that developed at 5°C. This increase was accentuated in pho1-2 and absent in pho2-1. NADP-glyceraldehyde-3-phosphate dehydrogenase, plastidic fructose-1,6-bisphosphatase and aldolase activity increase relative to phosphoglycerate kinase, transketolase and phosphoribulokinase in wild-type leaves at 5°C. This shift was accentuated in pho1-2 and reversed in pho2-1. Transcript levels for COR genes increase transiently 1 day after transfer to 5°C but were very low in leaves that developed at 5°C in wild-type Arabidopsis, pho1-2 and pho2-1. We conclude that low phosphate plays an important role in triggering cold acclimatization of leaves, leading in particular to an increase of Rubisco expression, changes in other Calvin cycle enzymes to minimize sequestration of phosphate in metabolites, and increased expression of sucrose biosynthesis enzymes. [source]

A novel synthetic mammalian promoter derived from an internal ribosome entry site

BIOTECHNOLOGY & BIOENGINEERING, Issue 4 2006
Shizuka Hartenbach
Abstract Introduction of specific mutations into a synthetic internal ribosome entry site (IRESGTX) derived from the GTX homeodomain protein revealed additional transcriptional activity. This novel synthetic PGTX promoter exhibited consensus core promoter modules such as the initiator (Inr) and the partial downstream promoter elements (DPE) and mediated high-level expression of a variety of transgenes including the human vascular endothelial growth factor 121 (VEGF121), the human placental secreted alkaline phosphatase (SEAP), and the Bacillus stearothermophilus -derived secreted ,-amylase (SAMY) in Chinese hamster ovary cells (CHO-K1) and a variety of other mammalian and human cell lines. The spacing between Inr and DPE modules was found to be critical for promoter performance since introduction of a single nucleotide (resulting in PGTX2) doubled the SEAP expression levels in CHO-K1. PGTX2 reached near 70% of PSV40 -driven expression levels and outperformed constitutive phosphoglycerate kinase (PPGK) and human ubiquitin C (PhUBC) promoters in CHO-K1. Also, PGTX2 was successfully engineered for macrolide-inducible transgene expression. Owing to its size of only 182 bp, PGTX2 is one of the smallest eukaryotic promoters. Although PGTX2 was found to be a potent promoter, it retained its IRESGTX -specific translation-initiation capacity. Synthetic DNAs, which combine multiple activities in a most compact sequence format may foster advances in therapeutic engineering of mammalian cells. © 2006 Wiley Periodicals, Inc. [source]