DOCSLIB.ORG

Interaction of 6-Phosphofructo-2-Kinase/Fructose-2,6- Bisphosphatase (PFK-2/Fbpase-2) with Glucokinase Activates Glucose Phospho

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Interaction of 6-Phosphofructo-2-Kinase/Fructose-2,6- Bisphosphatase (PFK-2/Fbpase-2) with Glucokinase Activates Glucose Phospho Interaction of 6-Phosphofructo-2-Kinase/Fructose-2,6- Bisphosphatase (PFK-2/FBPase-2) With Glucokinase Activates Glucose Phosphorylation and Glucose Metabolism in Insulin-Producing Cells Laura Massa,1 Simone Baltrusch,1 David A. Okar,2,3 Alex J. Lange,2 Sigurd Lenzen,1 and Markus Tiedge1 The bifunctional enzyme 6-phosphofructo-2-kinase/ fructose-2,6-bisphosphatase (PFK-2/FBPase-2) was re- cently identified as a new intracellular binding partner he enzyme glucokinase (GK) plays a pivotal role for glucokinase (GK). Therefore, we studied the impor- in the recognition of glucose in pancreatic tance of this interaction for the activity status of GK ␤-cells and the regulation of glucose metabolism and glucose metabolism in insulin-producing cells by Tin the liver (1–7). In pancreatic ␤-cells, GK acts overexpression of the rat liver and pancreatic islet as a glucose sensor and catalyzes the rate-limiting step for isoforms of PFK-2/FBPase-2. PFK-2/FBPase-2 overex- initiation of glucose-induced insulin secretion (6). GK is pression in RINm5F-GK cells significantly increased the regulated in a complex manner in pancreatic ␤-cells by GK activity by 78% in cells expressing the islet isoform, posttranslational modifications of the enzyme protein that by 130% in cells expressing the liver isoform, and by mainly depend on the intracellular glucose concentration 116% in cells expressing a cAMP-insensitive liver S32A/ (8–13). These posttranslational mechanisms of GK activity H258A double mutant isoform. Only in cells overex- regulation are comprised of conformational changes pressing the wild-type liver PFK-2/FBPase-2 isoform (14,15), sulfhydryl-group conversions (16–18), and inter- was the increase of GK activity abolished by forskolin, ␤ apparently due to the regulatory site for phosphoryla- actions with -cell matrix proteins (13,19), insulin gran- tion by a cAMP-dependent protein kinase. In cells over- ules (20,21), newly identified binding partners (22,23), and expressing any isoform of the PFK-2/FBPase-2, the GK-activating compounds (24). The hepatic GK regulatory increase of the GK enzyme activity was antagonized by protein, which binds and inhibits GK competitively and treatment with anti–FBPase-2 antibody. Increasing the confers short-term regulation of GK in the liver (25,26), is glucose concentration from 2 to 10 mmol/l had a signif- not expressed in pancreatic ␤-cells (13). Using a peptide icant stimulatory effect on the GK activity in phage display strategy, we recently identified the bifunctional RINm5F-GK cells overexpressing any isoform of PFK-2/ enzyme 6-phosphofructo-2-kinase/fructose-2,6-bisphos- FBPase-2. The interaction of GK with PFK-2/FBPase-2 phatase (PFK-2/FBPase-2) as a binding partner of the GK takes place at glucose concentrations that are physio- (23). PFK-2/FBPase-2 modulates intracellular levels of logically relevant for the activation of GK and the fructose-2,6-bisphosphate (F-2,6-P2), a highly potent regu- regulation of glucose-induced insulin secretion. This lator of carbohydrate metabolism (27–29). In liver, the new mechanism of posttranslational GK regulation may PFK-2/FBPase-2 enzyme is modulated by phosphorylation also represent a new site for pharmacotherapeutic in- tervention in type 2 diabetes treatment. Diabetes 53: and dephosphorylation, which significantly affects the 1020–1029, 2004 kinase/bisphosphatase ratio of this bifunctional enzyme (28,29). Rat pancreatic islets express the brain isoform of PFK-2/FBPase-2 (23), which does not appear to be regu- lated by cAMP-dependent protein kinases (PKAs) or phos- phatases at the NH2-terminus of the protein, as is the liver isoform (29). However, yeast two-hybrid studies clearly indicate that the GK protein interacts with the liver as well From the 1Institute of Clinical Biochemistry, Hannover Medical School, Hannover, Germany; the 2Department of Biochemistry, Molecular Biology and as the islet PFK-2/FBPase-2 isoform (23). This raised the Biophysics, University of Minnesota, Minneapolis, Minnesota; and the 3VA question whether the PFK-2/FBPase-2–GK interaction par- Medical Center, Minneapolis, Minnesota. ticipates in the posttranslational regulation of GK enzyme Address correspondence and reprint requests to Dr. Markus Tiedge, Insti- tute of Clinical Biochemistry, Hannover Medical School, D-30623 Hannover, activity. Knowledge of the physiological significance of GK Germany. E-mail: [email protected]. regulation through interaction with PFK-2/FBPase-2 may Received for publication 17 October 2003 and accepted in revised form 5 January 2004. have a central impact on the understanding of the failure L.M and S.B. contributed equally to this work. of ␤-cell function in type 2 diabetes. To elucidate the effect F-2,6-P2, fructose-2,6-bisphosphate; GK, glucokinase; MOI, multiplicity of of PFK-2/FBPase-2 binding to GK on GK enzyme activity infection; PKA, cAMP-dependent protein kinase; PFK-2/FBPase-2,6-phospho- fructo-2-kinase/fructose-2,6-bisphosphatase. and glucose metabolism, the liver and islet PFK-2/FBPase-2 © 2004 by the American Diabetes Association. isoforms were overexpressed in the present study in 1020 DIABETES, VOL. 53, APRIL 2004 L. MASSA AND ASSOCIATES RINm5F-GK and INS1 insulin-producing cells. The results er’s manual. The recombinant protein was characterized through SDS-PAGE show that overexpression of PFK-2/FBPase-2 resulted in a and activity measurements (42). The protein concentration was analyzed by a Bio-Rad protein assay. Then, 1 mg of FBPase-2 protein was diluted in 500 ␮l significant increase of GK activity in insulin-producing PBS and mixed with an equal volume of complete Freund’s adjuvant. Leghorn cells accompanied by corresponding increases in glucose hens were immunized by injecting the antigen into the pectoral muscle. Two metabolism. booster injections of 0.5 mg antigen mixed with incomplete Freund’s adjuvant were given 8 and 21 days later. Eggs collected 28 days after the first immunization were used for isolation of IgY from the yolk according to a RESEARCH DESIGN AND METHODS polyethylene glycol procedure (43). Serial dilutions of the IgY-FBPase-2 Materials. Restriction enzymes and modifying enzymes for the cloning polyclonal antibody were analyzed to detect the recombinant FBPase-2 procedures were from New England Biolabs (Beverly, MA) or Fermentas (St. protein and rat liver PFK-2/FBPase-2 by Western blot analysis. Leo-Rot, Germany). The SP6/T7 Transcription Kit and DIG Nucleic Acid Western blot analyses. Cells were homogenized by sonication in PBS (pH Detection Kit were obtained from Roche (Mannheim, Germany). Hybond 7.4), and insoluble material was pelleted by centrifugation. The protein nylon membranes were from Amersham (Braunschweig, Germany), and concentration was quantified by a Bio-Rad protein assay. Thereafter, dithio- Immobilon-P polyvinylidine difluoride membranes were from Millipore (Bed- threitol and bromophenol blue were added from concentrated stocks to yield ford, MA). The enhanced chemiluminescence detection system and autora- a final concentration of 100 mmol/l and 0.1%, respectively. Cellular protein (20 diography films were from Amersham. Forskolin was from ICN Biomedicals ␮g) was fractionated by reducing 10% SDS-PAGE and electroblotted to (Irvine, CA). All reagents of analytical grade were from Merck (Darmstadt, polyvinylidine difluoride membranes. The membranes were stained by Pon- Germany). All tissue culture equipment was from Gibco Life Technologies ceau to verify the transfer of comparable amounts of cellular protein. (Gaithersburg, MD). Nonspecific binding sites of the membranes were blocked by nonfat dry milk Tissue culture. RINm5F cells (30,31) overexpressing GK (RINm5F-GK cells) overnight at 4°C. GK immunodetection was performed as described previ- were generated by stable transfection of the human ␤-cell GK cDNA (32) in ously (13,18). For PFK-2/FBPase-2, the blots were incubated with the de- the pcDNA3 vector as described previously (13,33). Cells were grown in RPMI scribed FBPase-2 antibody at a dilution of 1:10,000, followed by a 2-h 1640 medium supplemented with 10 mmol/l glucose, 10% (vol/vol) FCS, incubation period with an anti-IgY peroxidase-labeled secondary antibody at a penicillin, streptomycin, and 250 ␮g/ml G418 in a humidified atmosphere at dilution of 1:40,000 at room temperature. The specific protein bands were 37°C and 5% CO2. INS1 cells (passage 80–90) were grown in RPMI 1640 visualized by chemiluminescence using the enhanced chemiluminescence medium supplemented with 10 mmol/l glucose, 10% (vol/vol) FCS, 2 mmol/l detection system and quantified by densitometry using the Gel-Pro Analyser L-glutamine, 1 mmol/l sodium pyruvate, 10 mmol/l HEPES, 50 ␮mol/l 2-mer- software. Linearity of the band intensities of the autoradiograms was verified captoethanol, penicillin, and streptomycin in a humidified atmosphere at 37°C by serial dilutions of recombinant ␤-cell GK or rat liver FBPase-2 protein, and 5% CO2 (34). respectively (data not shown). Stable overexpression of PFK-2/FBPase-2 in RINm5F-GK cells. PFK-2/ Assay of GK enzyme activity. GK activity measurements and GK Western FBPase-2 coding cDNAs for rat liver (35), rat liver S32A/H258A double mutant blot analysis were performed from identical samples to achieve a direct (36,37), and rat islet/brain (23,38) were subcloned as a HindIII-ApaI fragment comparison between GK protein expression and activity. The cells were into the pcDNA3-Zeo expression vector by standard molecular biology tech- homogenized in PBS (pH 7.4), and insoluble material was pelleted by niques (39). RINm5F-GK cells were transfected with the vector DNA by the centrifugation. GK enzyme activity was measured in soluble fractions by an use of CLONfectin (Clontech, Palo Alto, CA) as described in the manufactur- enzyme-coupled photometric assay consisting of glucose-6-phosphate dehy- er’s manual. Positive clones were selected through resistance against Zeocin drogenase, ATP, and NADPH (44).
Load more

Recommended publications
  • New Nucleotide Sequence Data on the EMBL File Server
    .=) 1991 Oxford University Press Nucleic Acids Research, Vol. 19, No. 2 413 New nucleotide sequence data on the EMBL File Server October 30, 1990 to November 13, 1990 New nucleotide sequence data, available from the EMBL File Server, (see Stoehr, P.J. and Omond, R.A. (1989) Nucleic Acids Res., 17 (16), 6763 -6764), are reported below. Availability of all the newest sequence data is the result of collaboration between.the EMBL Data Library and GenBank' , and data are supplied regularly by both groups. Updates to existing data are not reported here. This report has been prepared by the EMBL Data Library. PRIMATES: Human casein kinase II alpha subunit mRNA, complete cds. Human specific HS5 DNA Lozeman F.J., Litchfield D.W., Piening C., Takio K., Walsh Ueda S., Washio K., Kurosaki K.; K.A., Krebs E.G.; Genomics 8:7-12(1990). X17579 Biochemistry 29:8436-8447(1990). M55268 Human mRNA for heat shock protein HSP27 Human mRNA for actin-binding protein (ABP-280) Carper S.W., Rocheleau T.A., Storm F.K.; Gorlin J.B., Yamin R., Egan S., Stewart M., Stossel T.P., Nucleic Acids Res. 18:6457-6457(1990). X54079 Kwiatkowski D.J., Hartwig J.H.; J. Cell Biol. 111:1089-1105(1990). X53416 Human Ig germline H-chain D-region Dxpl and Dxp'1 genes, 3' Human amiloride-binding protein, complete cds. end. Barbry P., Champe M., Chassande O., Munemitsu S., Champigny Huang C., Stollar B.David.; G., Lingueglia E., Maes P., Frelin C., Tartar A., Ullrich A., Unpublished. M37485 Lazdunski M.; Proc. Natl. Acad.
    [Show full text]
  • Cdna Sequence and Tissue Expression Analysis of Glucokinase from Liver of Grass Carp (Ctenopharyngodon Idella )
    African Journal of Biotechnology Vol. 11(3), pp. 534-542, 10 January, 2012 Available online at http://www.academicjournals.org/AJB DOI: 10.5897/AJB11.3174 ISSN 1684–5315 © 2012 Academic Journals Full Length Research Paper cDNA sequence and tissue expression analysis of glucokinase from liver of grass carp (Ctenopharyngodon idella ) CHENG Han-liang*, JI Nan-jing, PENG Yong-xing, SHEN Xin, XU Jian-he, DONG Zhi-guo and WU Chen-chen Jiangsu Key Laboratory of Marine Biotechnology, Huaihai Institute of Technology, Lianyungang 222005, People’s Republic of China. Accepted 19 December, 2011 A full-length cDNA coding glucokinase (GK) was cloned from the liver of grass carp ( Ctenopharyngodon idella ) by reverse transcriptase-polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends methods. The cDNA obtained was 2066 bp exclusive of poly (A) residues with a 1431 bp open reading frame encoding 476 amino acids. The GK protein has a calculated molecular weight of 53.7 kDa and isoelectric point of 5.11. Some conserved functional sites were found including one conserved hexokinase signature sequence Leu 156 -Phe 181 ; two N-linked glycosylation sites Asn 176 and Asn 214 ; one cell attachment sequence Arg 202 -Asp 204 ; one glycosaminoglycan attachment site Ser455 -Gly 458 . The amino acid sequence has a high similarity to GK of other species, the percent identity compared with topmouth culter, common carp, human and rat are 98.1, 96.8, 80.3 and 79.8%, respectively. Tissue distribution of GK mRNA in brain, mesenteric adipose tissue, spleen, white muscle and liver of grass carp was analyzed by SYBR real-time fluorescence quantitative RT-PCR method using β-actin as an internal control for cDNA normalization.
    [Show full text]
  • Structures, Functions, and Mechanisms of Filament Forming Enzymes: a Renaissance of Enzyme Filamentation
    Structures, Functions, and Mechanisms of Filament Forming Enzymes: A Renaissance of Enzyme Filamentation A Review By Chad K. Park & Nancy C. Horton Department of Molecular and Cellular Biology University of Arizona Tucson, AZ 85721 N. C. Horton ([email protected], ORCID: 0000-0003-2710-8284) C. K. Park ([email protected], ORCID: 0000-0003-1089-9091) Keywords: Enzyme, Regulation, DNA binding, Nuclease, Run-On Oligomerization, self-association 1 Abstract Filament formation by non-cytoskeletal enzymes has been known for decades, yet only relatively recently has its wide-spread role in enzyme regulation and biology come to be appreciated. This comprehensive review summarizes what is known for each enzyme confirmed to form filamentous structures in vitro, and for the many that are known only to form large self-assemblies within cells. For some enzymes, studies describing both the in vitro filamentous structures and cellular self-assembly formation are also known and described. Special attention is paid to the detailed structures of each type of enzyme filament, as well as the roles the structures play in enzyme regulation and in biology. Where it is known or hypothesized, the advantages conferred by enzyme filamentation are reviewed. Finally, the similarities, differences, and comparison to the SgrAI system are also highlighted. 2 Contents INTRODUCTION…………………………………………………………..4 STRUCTURALLY CHARACTERIZED ENZYME FILAMENTS…….5 Acetyl CoA Carboxylase (ACC)……………………………………………………………………5 Phosphofructokinase (PFK)……………………………………………………………………….6
    [Show full text]
  • Metabolic Plasticity Is an Essential Requirement of Acquired Tyrosine Kinase Inhibitor Resistance in Chronic Myeloid Leukemia
    cancers Article Metabolic Plasticity Is an Essential Requirement of Acquired Tyrosine Kinase Inhibitor Resistance in Chronic Myeloid Leukemia Miriam G. Contreras Mostazo 1,2,3, Nina Kurrle 3,4,5, Marta Casado 6,7 , Dominik Fuhrmann 8, Islam Alshamleh 4,9, Björn Häupl 3,4,5, Paloma Martín-Sanz 7,10, Bernhard Brüne 5,8,11 , 3,4,5 4,9 3,4,5, 1,2,7,12, , Hubert Serve , Harald Schwalbe , Frank Schnütgen y , Silvia Marin * y 1,2,7,12, , and Marta Cascante * y 1 Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, 08028 Barcelona, Spain; [email protected] 2 Institute of Biomedicine of University of Barcelona, 08028 Barcelona, Spain 3 Department of Medicine, Hematology/Oncology, University Hospital Frankfurt, Goethe-University, 60590 Frankfurt am Main, Germany; [email protected] (N.K.); [email protected] (B.H.); [email protected] (H.S.); [email protected] (F.S.) 4 German Cancer Consortium (DKTK), Partner Site Frankfurt/Mainz, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany; [email protected] (I.A.); [email protected] (H.S.) 5 Frankfurt Cancer Institute (FCI), Goethe University, 60590 Frankfurt am Main, Germany; [email protected] 6 Biomedicine Institute of Valencia, IBV-CSIC, 46010 Valencia, Spain; [email protected] 7 CIBER of Hepatic and Digestive Diseases (CIBEREHD), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain; [email protected] 8 Institute of Biochemistry I, Faculty of
    [Show full text]
  • Insulin Resistance Related Signaling Pathways in the Liver
    INSULIN RESISTANCE RELATED SIGNALING PATHWAYS IN THE LIVER by Yuchun Wang A thesis submitted to Johns Hopkins University in conformity with the requirements for the degree of Master of Science in Engineering Baltimore, Maryland May, 2020 © 2020 Yuchun Wang All rights reserved Abstract Over the past 20 years, the worldwide toll of diabetes has tripled to more than 400 million, which makes it one of the fastest-growing health challenges of the 21st century. There are three main categories of diabetes: type 1, type 2 and gestational diabetes mellitus. Among them, Type 2 diabetes(T2D) makes up to 90% of diabetes worldwide. Hyper- glycemia can be effectively controlled by giving insulin injection for type 1 and gestational diabetes mellitus. However, because insulin resistance is one of the causes of T2D, those with T2D do not respond as well to insulin as those with T1D or gestational diabetes. Fur- thermore, our lack of knowledge about the underlying physiology of T2D makes it difficult to find reliable treatments. While high blood glucose concentration is one of the major symptoms of T2D, changes in lipid metabolism are characteristic of insulin resistance(IR). In the human body, the liver plays a major role in glucose homeostasis and lipid metabolism. Hence, this essay pro- vides an overview of signaling pathways in the liver and presents their interrelationship to better understand the underlying IR mechanism. Primary Reader and Advisor: Marc D. Donohue Secondary Reader: Gregory Aranovich ii Acknowledgements I wish to express my deepest gratitude to my advisor, Professor Marc D. Donohue, for introducing me to the fantastic world of science, and for his patient guidance along the road of my Master’s study.
    [Show full text]
  • Supplemental Information
    Supplemental Figures Supplemental Figure 1. 1 Supplemental Figure 1. (A) Fold changes in the mRNA expression levels of genes involved in glucose metabolism, pentose phosphate pathway (PPP), lipid biosynthesis and beta cell markers, in sorted beta cells from MIP-GFP adult mice (P25) compared to beta cells from neonatal MIP-GFP mice (P4). (N=1; pool of cells sorted from 6-8 mice in each group). (B) Fold changes in the mRNA expression levels of genes involved in glucose metabolism, pentose phosphate pathway (PPP), lipid biosynthesis and beta cell markers, in quiescent MEFs compared to proliferating MEFs. (N=1). (C) Expression Glut2 (red) in representative pancreatic sections from wildtype mice at indicated ages, by immunostaining. DAPI (blue) counter-stains the nuclei. (D) Bisulfite sequencing analysis for the Ldha and AldoB loci at indicated regions comparing sorted beta cells from P4 and P25 MIP-GFP mice (representative clones from N=3 mice). Each horizontal line with dots is an independent clone and 10 clones are shown here. These regions are almost fully DNA methylated (filled circles) in beta cells from P25 mice, but largely hypomethylated (open circles) in beta cells from P4 mice. For all experiments unless indicated otherwise, N=3 independent experiments. 2 Supplemental Figure 2. 3 Supplemental Figure 2. (A) Expression profile of Dnmt3a in representative pancreatic sections from wildtyype mice at indicated ages (P1 to 6 weeks) using immunostaining for Dnmt3a (red) and insulin (Ins; green). DAPI (blue) counter-stains the nuclei. (B) Representative pancreatic sections from 2 weeks old 3aRCTom-KO and littermate control 3aRCTom-Het animals, immunostained for Dnmt3a (red) and GFP (green).
    [Show full text]
  • The Effects of Bone Marrow Adipocytes on Metabolic Regulation in Metastatic Prostate Cancer" (2017)
    Wayne State University Wayne State University Dissertations 1-1-2017 The ffecE ts Of Bone Marrow Adipocytes On Metabolic Regulation In Metastatic Prostate Cancer Jonathan Diedrich Wayne State University, Follow this and additional works at: https://digitalcommons.wayne.edu/oa_dissertations Part of the Oncology Commons Recommended Citation Diedrich, Jonathan, "The Effects Of Bone Marrow Adipocytes On Metabolic Regulation In Metastatic Prostate Cancer" (2017). Wayne State University Dissertations. 1797. https://digitalcommons.wayne.edu/oa_dissertations/1797 This Open Access Dissertation is brought to you for free and open access by DigitalCommons@WayneState. It has been accepted for inclusion in Wayne State University Dissertations by an authorized administrator of DigitalCommons@WayneState. THE EFFECTS OF BONE MARROW ADIPOCYTES ON METASTATIC PROSTATE CANCER CELL METABOLISM AND SIGNALLING by JONATHAN DRISCOLL DIEDRICH DISSERTATION Submitted to the Graduate School of Wayne State University, Detroit, Michigan in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY 2017 MAJOR: CANCER BIOLOGY Approved By: Advisor Date © COPYRIGHT BY JONATHAN DIEDRICH 2017 All Rights Reserved DEDICATION To my Family, Friends, and Wally ii ACKNOWLEDGMENTS When I joined the Podgorski laboratory in April of 2014, I had finished my rotations and spent some time in a collaborating laboratory honing my technical and creative thinking skills to become a valuable asset to her team; however, I was still unprepared for the exciting journey it would be through Izabela’s laboratory over the last three years. I was extremely lucky to have landed in Dr. Podgorski’s laboratory and will be forever thankful for the tremendous support she has given me to aid in my development as an independent investigator.
    [Show full text]
  • Recruitment and Expansion of Tregs Cells in the Tumor Environment—How to Target Them?
    cancers Review Recruitment and Expansion of Tregs Cells in the Tumor Environment—How to Target Them? Justine Cinier 1,†, Margaux Hubert 1,†, Laurie Besson 1, Anthony Di Roio 1 ,Céline Rodriguez 1, Vincent Lombardi 2, Christophe Caux 1,‡ and Christine Ménétrier-Caux 1,*,‡ 1 University of Lyon, Claude Bernard Lyon 1 University, INSERM U-1052, CNRS 5286 Centre Léon Bérard, Cancer Research Center of Lyon (CRCL), 69008 Lyon, France; [email protected] (J.C.); [email protected] (M.H.); [email protected] (L.B.); [email protected] (A.D.R.); [email protected] (C.R.); [email protected] (C.C.) 2 Institut de Recherche Servier, 125 Chemin de Ronde, 78290 Croissy-sur-Seine, France; [email protected] * Correspondence: [email protected] † Co-first authorship. ‡ Co-last authorship. Simple Summary: The immune response against cancer is generated by effector T cells, among them cytotoxic CD8+ T cells that destroy cancer cells and helper CD4+ T cells that mediate and support the immune response. This antitumor function of T cells is tightly regulated by a particular subset of CD4+ T cells, named regulatory T cells (Tregs), through different mechanisms. Even if the complete inhibition of Tregs would be extremely harmful due to their tolerogenic role in impeding autoimmune diseases in the periphery, the targeted blockade of their accumulation at tumor sites or their targeted Citation: Cinier, J.; Hubert, M.; depletion represent a major therapeutic challenge. This review focuses on the mechanisms favoring Besson, L.; Di Roio, A.; Rodriguez, C.; Treg recruitment, expansion and stabilization in the tumor microenvironment and the therapeutic Lombardi, V.; Caux, C.; strategies developed to block these mechanisms.
    [Show full text]
  • A Review of Isozymes in Cancer1
    Cancer Research VOLUME31 NOVEMBER 1971 NUMBER11 [CANCER RESEARCH 31, 1523-1542, November 1971] A Review of Isozymes in Cancer1 Wayne E. Criss Department of Obstetrics and Gynecology, University of Florida College of Medicine, Gainesville, Florida 32601 TABLE OF CONTENTS postulated role for that particular isozymic system in cellular metabolism. Summary 1523 Introduction 1523 Normal enzyme differentiation 1523 INTRODUCTION Tumor enzyme differentiation 1524 Isozymes 1524 Normal Enzyme Differentiation DNA polymerase 1524 Enzyme differentiation is the process whereby, during the Hexokinase 1525 Fructose 1,6-diphosphatase 1525 development of an organ in an animal, the organ acquires the quantitative and qualitative adult enzyme patterns (122). Key Aldolase 1526 pathway enzymes in several metabolic processes have been Pyruvate kinase 1527 found to undergo enzymatic differentiation. The enzymes Láclatedehydrogenase 1527 Isocitrate dehydrogenase 1527 involved in nitrogen metabolism, and also in urea cycle Malate dehydrogenase 1528 metabolism (180), are tyrosine aminotransferase (123, 151, Glycerol phosphate dehydrogenase 1529 330, 410), tryptophan pyrrolase (261), serine dehydratase Glutaminase 1529 (123, 410), histidine ammonia lyase (11), and aspartate Aspartate aminotransferase 1530 aminotransferase (337, 388). The enzymes involved in nucleic Adenylate kinase 1531 acid metabolism are DNA polymerase (156, 277) and RNase (52). In glycolysis the enzymes are hexokinase-glucokinase Carbamyl phosphate synthetase 1531 Lactose synthetase 1533 (98, 389), galactokinase 30, aldolase (267, 315), pyruvate Discussion 1533 kinase (73, 386), and lactate dehydrogenase (67, 69). In References 1533 mitochondrial oxidation they are NADH oxidase, succinic oxidase, a-glycero-P oxidase, ATPase, cytochrome oxidase, and flavin content (84, 296). In glycogen metabolism the SUMMARY enzymes involved are UDPG pyrophosphorylase and UDPG glucosyltransferase (19).
    [Show full text]
  • Glycolysis and Gluconeogenesis Are Regulated Independently
    Substrate cycles in glucose metabolism Glycolysis and gluconeogenesis! are regulated independently (the ΔG! values shown are for the corresponding! reactions in liver; in kJ/mol). All six! reactions are exergonic.! Cellular [F2,6BP] depends on the balance between its! rates of synthesis and degradation by PFK-2 ! (phosphofructokinase-2) and FBPase-2 (fructose bisphosphatase-2).! These activities are located on different domains of the! same homodimeric protein (a bifunctional enzyme).! The bifunctional enzyme is regulated by allosteric effectors and by! phosphorylation/dephosphorylation catalyzed by PKA (protein! kinase A) and a phosphoprotein phosphatase.! F2,6BP activates PFK-1 and inhibits FBPase-1. When blood [glucose] is high, cAMP levels decrease, and [F2,6BP]! rises, promoting glycolysis.! The F2,6BP control system in muscle differs from that in liver.! Hormones that stimulate glycogen breakdown in heart muscle lead to phosphorylation of the bifunctional enzyme that stimulates rather than inhibits PFK-2. The increasing [F2,6BP] stimulates glycolysis so that glycogen breakdown and glycolysis are coordinated.! The skeletal muscle PFK-2/PBPase-2 isozyme lacks a phosphorylation! site and is thus not subject to cAMP-dependent control.! Alanine inhibits pyruvate kinase.! Alanine, a major gluconeogenic precursor, inhibits PK.! Liver PK is also inactivated by phosphorylation. Phosphorylation! activates glycogen phosphorylase and FBPase-2: thus the pathways of ! gluconeogenesis and glycogen breakdown both flow towards G6P, ! which is converted to glucose for export from the liver.! Hexokinase/glucokinase and G6Pase activities are also controlled.! Glucose metabolism is regulated by long-term changes in the amounts of enzymes synthesized.! Rates of transcription and mRNA stabilities encoding regulatory enzymes are influenced by hormones.
    [Show full text]
  • Metabolic Network-Based Stratification of Hepatocellular Carcinoma Reveals Three Distinct Tumor Subtypes
    Metabolic network-based stratification of hepatocellular carcinoma reveals three distinct tumor subtypes Gholamreza Bidkhoria,b,1, Rui Benfeitasa,1, Martina Klevstigc,d, Cheng Zhanga, Jens Nielsene, Mathias Uhlena, Jan Borenc,d, and Adil Mardinoglua,b,e,2 aScience for Life Laboratory, KTH Royal Institute of Technology, SE-17121 Stockholm, Sweden; bCentre for Host-Microbiome Interactions, Dental Institute, King’s College London, SE1 9RT London, United Kingdom; cDepartment of Molecular and Clinical Medicine, University of Gothenburg, SE-41345 Gothenburg, Sweden; dThe Wallenberg Laboratory, Sahlgrenska University Hospital, SE-41345 Gothenburg, Sweden; and eDepartment of Biology and Biological Engineering, Chalmers University of Technology, SE-41296 Gothenburg, Sweden Edited by Sang Yup Lee, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea, and approved November 1, 2018 (received for review April 27, 2018) Hepatocellular carcinoma (HCC) is one of the most frequent forms of of markers associated with recurrence and poor prognosis (13–15). liver cancer, and effective treatment methods are limited due to Moreover, genome-scale metabolic models (GEMs), collections tumor heterogeneity. There is a great need for comprehensive of biochemical reactions, and associated enzymes and transporters approaches to stratify HCC patients, gain biological insights into have been successfully used to characterize the metabolism of subtypes, and ultimately identify effective therapeutic targets. We HCC, as well as identify drug targets for HCC patients (11, 16–18). stratified HCC patients and characterized each subtype using tran- For instance, HCC tumors have been stratified based on the uti- scriptomics data, genome-scale metabolic networks and network lization of acetate (11). Analysis of HCC metabolism has also led topology/controllability analysis.
    [Show full text]
  • MTOR Signaling and Metabolism in Early T Cell Development
    G C A T T A C G G C A T genes Review MTOR Signaling and Metabolism in Early T Cell Development Guy Werlen, Ritika Jain and Estela Jacinto * Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, Piscataway, NJ 08854, USA; [email protected] (G.W.); [email protected] (R.J.) * Correspondence: [email protected]; Tel.: +1-732-235-4476 Abstract: The mechanistic target of rapamycin (mTOR) controls cell fate and responses via its func- tions in regulating metabolism. Its role in controlling immunity was unraveled by early studies on the immunosuppressive properties of rapamycin. Recent studies have provided insights on how metabolic reprogramming and mTOR signaling impact peripheral T cell activation and fate. The contribution of mTOR and metabolism during early T-cell development in the thymus is also emerging and is the subject of this review. Two major T lineages with distinct immune functions and peripheral homing organs diverge during early thymic development; the αβ- and γδ-T cells, which are defined by their respective TCR subunits. Thymic T-regulatory cells, which have immunosup- pressive functions, also develop in the thymus from positively selected αβ-T cells. Here, we review recent findings on how the two mTOR protein complexes, mTORC1 and mTORC2, and the signaling molecules involved in the mTOR pathway are involved in thymocyte differentiation. We discuss emerging views on how metabolic remodeling impacts early T cell development and how this can be mediated via mTOR signaling. Keywords: mTOR; mTORC1; mTORC2; thymocytes; T lymphocytes; early T cell development; T-cell metabolism Citation: Werlen, G.; Jain, R.; Jacinto, E.
    [Show full text]