scholarly journals Activity and genomic organization of human glucose transporter 9 (GLUT9), a novel member of the family of sugar-transport facilitators predominantly expressed in brain and leucocytes

2001 ◽  
Vol 358 (3) ◽  
pp. 791-792 ◽  
Author(s):  
H. DOEGE ◽  
A. BOCIANSKI ◽  
H.-G. JOOST ◽  
A. SCHÜRMANN
Keyword(s):  
Glucose Transporter ◽  
Genomic Organization ◽  
Sugar Transport ◽  
The Family ◽  
Glucose Transporter 9

scholarly journals Activity and genomic organization of human glucose transporter 9 (GLUT9), a novel member of the family of sugar-transport facilitators predominantly expressed in brain and leucocytes

2000 ◽  
Vol 350 (3) ◽  
pp. 771-776 ◽  
Author(s):  
Holger DOEGE ◽  
Andreas BOCIANSKI ◽  
Hans-Georg JOOST ◽  
Annette SCHÜRMANN
Keyword(s):  
Amino Acid ◽  
Glucose Transporter ◽  
Sequence Similarity ◽  
Organic Anion ◽  
Sugar Transport ◽  
Amino Acid Identity ◽  
Transport Activity ◽  
Anion Transporters ◽  
The Family ◽  
Glucose Transporter 9

The GLUT9 gene encodes a cDNA which exhibits significant sequence similarity with members of the glucose transporter (GLUT) family. The gene is located on chromosome 9q34 and consists of 10 exons separated by short introns. The amino acid sequence deduced from its cDNA predicts 12 putative membrane-spanning helices and all the motifs (sugar-transporter signatures) that have previously been shown to be essential for transport activity. A striking characteristic of GLUT9 is the presence of two arginines in the putative helices 7 and 8 at positions where the organic anion transporters harbour basic residues. The next relative of GLUT9 is the glucose transporter GLUT8/GLUTX1 (44.8% amino acid identity with GLUT9). A 2.6-kb transcript of GLUT9 was detected in spleen, peripheral leucocytes and brain. Transfection of COS-7 cells with GLUT9 produced expression of a 46-kDa membrane protein which exhibited reconstitutable glucose-transport activity and low-affinity cytochalasin-B binding. It is concluded that GLUT9 is a novel member of the family of sugar-transport facilitators with a tissue-specific function.

Effect of Addition of WZB117 as an Inhibitor of Glucose Transporter 1 for Venous Blood Glucose Determination

2020 ◽  
Author(s):  
Lei Zhang ◽  
Yaqiong Ran ◽  
Yan Zhu ◽  
Qianna Zhen
Keyword(s):  
Blood Glucose ◽  
Glucose Level ◽  
Glucose Transporter ◽  
Venous Blood ◽  
Sugar Transport ◽  
Glucose Transporter 1 ◽  
Glucose Determination ◽  
Glucose Levels ◽  
Significant Difference ◽  
Blood Glucose Determination

Abstract Objective Sodium fluoride (NaF) has been applied to inhibit glycolysis in venous specimens for decades. However, it has had little effect on the rate of glycolysis in the first 1 to 2 hours, resulting in a decrease of glucose, so a more efficient method is needed. Recently, we discovered that WZB117, a specific Glut1 inhibitor, restricts glycolysis by inhibiting the passive sugar transport of human red blood cells and cancer cells. The purpose of this study was to evaluate the results of intravenous blood glucose determination after the addition of WZB117. Methods Venous specimens from 40 pairs of healthy volunteers were collected for several days and placed in tubes containing NaF plus EDTA-disodium (Na2) without WZB117 (the A group); citric acid, trisodium citrate, and EDTA-Na2 without WZB117 (B group); and NaF plus EDTA-Na2 with WZB117 (C group). The glucose concentration was measured after venipuncture and compared with test tubes treated for 1 hour, 2 hours, and 3 hours before centrifugation. Glucose level was determined by the hexokinase method. The paired t-test was used to examine differences in glucose values at baseline and at different time points. The number of misdiagnoses and the misdiagnosis rate were calculated at 2 diagnostic stages: high risk of diabetes (glucose level of 6.1 mmol/L) and diagnosis of diabetes (glucose level of 7.0 mmol/L). Results Glucose levels decreased by 1.0% at 1 hour and by 2.1% at 3 hours in the C group tubes and simultaneously decreased by 1.7% at 1 hour and by 2.5% at 3 hours in the B group tubes. In contrast, glucose levels decreased by 4.1% at 1 hour and by 6.3% at 3 hours in the A group tubes. There was a statistically significant difference in glucose levels measured in the A group tubes and B group tubes at 1 hour, 2 hours, and 3 hours. The misdiagnosis rate of clinical diagnosis in diabetes was highest in the A group tubes (7.0‰ at 1 hour, 0.1‰ at 3 hours at 7.0 mmol/L point; 14.6‰ at 1 hour, 0.4‰ at 3 hours at 6.1 mmol/L point) and lowest in the C group tubes (2.95‰ at 1 hour, 0‰ at 3 hours at 7.0 mmol/L point; 4.8‰ at 1 hour, 0.1‰ at 3 hours at 6.1 mmol/L point). Conclusion The tube addition of WZB117 is more suitable for minimizing glycolysis and has no effect on glucose levels even if specimens are left uncentrifuged for up to 3 hours.

Hypouricemic Effects ofArmillaria melleaon Hyperuricemic Mice Regulated through OAT1 and CNT2

2018 ◽  
Vol 46 (03) ◽  
pp. 585-599 ◽  
Author(s):  
Tianqiao Yong ◽  
Shaodan Chen ◽  
Yizhen Xie ◽  
Diling Chen ◽  
Jiyan Su ◽  
...  
Keyword(s):  
Gastrointestinal Tract ◽  
Glucose Transporter ◽  
Organic Anion ◽  
Inhibitory Effect ◽  
Organic Anion Transporter ◽  
Nucleoside Transporter ◽  
Inhibitory Effects ◽  
Concentrative Nucleoside Transporter ◽  
Anion Transporter ◽  
Glucose Transporter 9

Ethanol and water extracts of Armillaria mellea were prepared by directly soaking A. mellea in ethanol (AME) at 65[Formula: see text]C, followed by decocting the remains in water (AMW) at 85[Formula: see text]C. Significantly, AME and AMW at 30, 60 and 120[Formula: see text]mg/kg exhibited excellent hypouricemic actions, causing remarkable declines from hyperuricemic control (351[Formula: see text][Formula: see text]mol/L, [Formula: see text]) to 136, 130 and 115[Formula: see text][Formula: see text]mol/L and 250, 188 and 152[Formula: see text][Formula: see text]mol/L in serum uric acid, correspondingly. In contrast to the evident renal toxicity of allopurinol, these preparations showed little impacts. Moreover, they showed some inhibitory effect on XOD (xanthine oxidase) activity. Compared with hyperuricemic control, protein expressions of OAT1 (organic anion transporter 1) were significantly elevated in AME- and AMW-treated mice. The levels of GLUT9 (glucose transporter 9) expression were significantly decreased by AMW. CNT2 (concentrative nucleoside transporter 2), a key target for purine absorption in gastrointestinal tract was involved in this study, and was verified for its innovative role. Both AME and AMW down-regulated CNT2 proteins in the gastrointestinal tract in hyperuricemic mice. As they exhibited considerable inhibitory effects on XOD, we selected XOD as the target for virtual screening by using molecular docking, and four compounds were hit with high ranks. From the analysis, we concluded that hydrogen bond, Pi–Pi and Pi-sigma interactions might play important roles for their orientations and locations in XOD inhibition.

scholarly journals Identification of New Regulators of the Oocyte-to-Embryo Transition in Drosophila

2020 ◽  
Vol 10 (9) ◽  
pp. 2989-2998
Author(s):  
Emir E Avilés-Pagán ◽  
Albert S W Kang ◽  
Terry L Orr-Weaver
Keyword(s):  
Oocyte Maturation ◽  
Glucose Transporter ◽  
Sugar Transport ◽  
Degradation Pathway ◽  
Female Fertility ◽  
Egg Activation ◽  
Developmentally Regulated ◽  
Glycogen Accumulation ◽  
Aquaporin Gene ◽  
F Box Protein

Abstract At the oocyte-to-embryo transition the highly differentiated oocyte arrested in meiosis becomes a totipotent embryo capable of embryogenesis. Oocyte maturation (release of the prophase I primary arrest) and egg activation (release from the secondary meiotic arrest and the trigger for the oocyte-to-embryo transition) serve as prerequisites for this transition, both events being controlled posttranscriptionally. Recently, we obtained a comprehensive list of proteins whose levels are developmentally regulated during these events via a high-throughput quantitative proteomic analysis of Drosophila melanogaster oocyte maturation and egg activation. We conducted a targeted screen for potential novel regulators of the oocyte-to-embryo transition, selecting 53 candidates from these proteins. We reduced the function of each candidate gene using transposable element insertion alleles and RNAi, and screened for defects in oocyte maturation or early embryogenesis. Deletion of the aquaporin gene CG7777 did not affect female fertility. However, we identified CG5003 and nebu (CG10960) as new regulators of the transition from oocyte to embryo. Mutations in CG5003, which encodes an F-box protein associated with SCF-proteasome degradation function, cause a decrease in female fertility and early embryonic arrest. Mutations in nebu, encoding a putative glucose transporter, result in defects during the early embryonic divisions, as well as a developmental delay and arrest. nebu mutants also exhibit a defect in glycogen accumulation during late oogenesis. Our findings highlight potential previously unknown roles for the ubiquitin protein degradation pathway and sugar transport across membranes during this time, and paint a broader picture of the underlying requirements of the oocyte-to-embryo transition.

scholarly journals Caffeine inhibits glucose transport by binding at the GLUT1 nucleotide-binding site

2015 ◽  
Vol 308 (10) ◽  
pp. C827-C834 ◽  
Author(s):  
Jay M. Sage ◽  
Anthony J. Cura ◽  
Kenneth P. Lloyd ◽  
Anthony Carruthers
Keyword(s):  
Binding Site ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Cytochalasin B ◽  
Sugar Transport ◽  
Nucleotide Binding ◽  
Nucleotide Binding Site ◽  
Sugar Uptake ◽  
Glucose Transporter 1 ◽  
Intracellular Atp

Glucose transporter 1 (GLUT1) is the primary glucose transport protein of the cardiovascular system and astroglia. A recent study proposes that caffeine uncompetitive inhibition of GLUT1 results from interactions at an exofacial GLUT1 site. Intracellular ATP is also an uncompetitive GLUT1 inhibitor and shares structural similarities with caffeine, suggesting that caffeine acts at the previously characterized endofacial GLUT1 nucleotide-binding site. We tested this by confirming that caffeine uncompetitively inhibits GLUT1-mediated 3- O-methylglucose uptake in human erythrocytes [ Vmax and Km for transport are reduced fourfold; Ki(app) = 3.5 mM caffeine]. ATP and AMP antagonize caffeine inhibition of 3- O-methylglucose uptake in erythrocyte ghosts by increasing Ki(app) for caffeine inhibition of transport from 0.9 ± 0.3 mM in the absence of intracellular nucleotides to 2.6 ± 0.6 and 2.4 ± 0.5 mM in the presence of 5 mM intracellular ATP or AMP, respectively. Extracellular ATP has no effect on sugar uptake or its inhibition by caffeine. Caffeine and ATP displace the fluorescent ATP derivative, trinitrophenyl-ATP, from the GLUT1 nucleotide-binding site, but d-glucose and the transport inhibitor cytochalasin B do not. Caffeine, but not ATP, inhibits cytochalasin B binding to GLUT1. Like ATP, caffeine renders the GLUT1 carboxy-terminus less accessible to peptide-directed antibodies, but cytochalasin B and d-glucose do not. These results suggest that the caffeine-binding site bridges two nonoverlapping GLUT1 endofacial sites—the regulatory, nucleotide-binding site and the cytochalasin B-binding site. Caffeine binding to GLUT1 mimics the action of ATP but not cytochalasin B on sugar transport. Molecular docking studies support this hypothesis.

Stimulation of glucose transport in skeletal muscle by hypoxia

1991 ◽  
Vol 70 (4) ◽  
pp. 1593-1600 ◽  
Author(s):  
G. D. Cartee ◽  
A. G. Douen ◽  
T. Ramlal ◽  
A. Klip ◽  
J. O. Holloszy
Keyword(s):  
Skeletal Muscle ◽  
Plasma Membrane ◽  
Muscle Contraction ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Cytochalasin B ◽  
Sugar Transport ◽  
Transport Activity ◽  
Hindlimb Muscles ◽  
Stimulation Of

Hypoxia caused a progressive cytochalasin B-inhibitable increase in the rate of 3-O-methylglucose transport in rat epitrochlearis muscles to a level approximately six-fold above basal. Muscle ATP concentration was well maintained during hypoxia, and increased glucose transport activity was still present after 15 min of reoxygenation despite repletion of phosphocreatine. However, the increase in glucose transport activity completely reversed during a 180-min-long recovery in oxygenated medium. In perfused rat hindlimb muscles, hypoxia caused an increase in glucose transporters in the plasma membrane, suggesting that glucose transporter translocation plays a role in the stimulation of glucose transport by hypoxia. The maximal effects of hypoxia and insulin on glucose transport activity were additive, whereas the effects of exercise and hypoxia were not, providing evidence suggesting that hypoxia and exercise stimulate glucose transport by the same mechanism. Caffeine, at a concentration too low to cause muscle contraction or an increase in glucose transport by itself, markedly potentiated the effect of a submaximal hypoxic stimulus on sugar transport. Dantrolene significantly inhibited the hypoxia-induced increase in 3-O-methylglucose transport. These effects of caffeine and dantrolene suggest that Ca2+ plays a role in the stimulation of glucose transport by hypoxia.

Identification of a novel glucose transporter-like protein—GLUT-12

2002 ◽  
Vol 282 (3) ◽  
pp. E733-E738 ◽  
Author(s):  
Suzanne Rogers ◽  
Maria L. Macheda ◽  
Susan E. Docherty ◽  
Maynard D. Carty ◽  
Michael A. Henderson ◽  
...  
Keyword(s):  
Breast Cancer Cells ◽  
Glucose Transporter ◽  
Sugar Transport ◽  
Amino Acid Identity ◽  
Specific Expression ◽  
Glut 4 ◽  
Glucose Transport System ◽  
Metabolic Properties ◽  
Mcf 7

Facilitative glucose transporters exhibit variable hexose affinity and tissue-specific expression. These characteristics contribute to specialized metabolic properties of cells. Here we describe the characterization of a novel glucose transporter-like molecule, GLUT-12. GLUT-12 was identified in MCF-7 breast cancer cells by homology to the insulin-regulatable glucose transporter GLUT-4. The GLUT-12 cDNA encodes 617 amino acids, which possess features essential for sugar transport. Di-leucine motifs are present in NH2 and COOH termini at positions similar to the GLUT-4 FQQI and LL targeting motifs. GLUT-12 exhibits 29% amino acid identity with GLUT-4 and 40% to the recently described GLUT-10. Like GLUT-10, a large extracellular domain is predicted between transmembrane domains 9 and 10. Genomic organization of GLUT-12 is highly conserved with GLUT-10 but distinct from GLUTs 1–5. Immunofluorescence showed that, in the absence of insulin, GLUT-12 is localized to the perinuclear region in MCF-7 cells. Immunoblotting demonstrated GLUT-12 expression in skeletal muscle, adipose tissue, and small intestine. Thus GLUT-12 is potentially part of a second insulin-responsive glucose transport system.

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