1
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Barnault R, Verzeroli C, Fournier C, Michelet M, Redavid AR, Chicherova I, Plissonnier ML, Adrait A, Khomich O, Chapus F, Richaud M, Hervieu M, Reiterer V, Centonze FG, Lucifora J, Bartosch B, Rivoire M, Farhan H, Couté Y, Mirakaj V, Decaens T, Mehlen P, Gibert B, Zoulim F, Parent R. Hepatic inflammation elicits production of proinflammatory netrin-1 through exclusive activation of translation. Hepatology 2022; 76:1345-1359. [PMID: 35253915 DOI: 10.1002/hep.32446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 02/16/2022] [Accepted: 02/17/2022] [Indexed: 12/18/2022]
Abstract
BACKGROUND AND AIMS Netrin-1 displays protumoral properties, though the pathological contexts and processes involved in its induction remain understudied. The liver is a major model of inflammation-associated cancer development, leading to HCC. APPROACH AND RESULTS A panel of cell biology and biochemistry approaches (reverse transcription quantitative polymerase chain reaction, reporter assays, run-on, polysome fractionation, cross linking immunoprecipitation, filter binding assay, subcellular fractionation, western blotting, immunoprecipitation, stable isotope labeling by amino acids in cell culture) on in vitro-grown primary hepatocytes, human liver cell lines, mouse samples and clinical samples was used. We identify netrin-1 as a hepatic inflammation-inducible factor and decipher its mode of activation through an exhaustive eliminative approach. We show that netrin-1 up-regulation relies on a hitherto unknown mode of induction, namely its exclusive translational activation. This process includes the transfer of NTN1 (netrin-1) mRNA to the endoplasmic reticulum and the direct interaction between the Staufen-1 protein and this transcript as well as netrin-1 mobilization from its cell-bound form. Finally, we explore the impact of a phase 2 clinical trial-tested humanized anti-netrin-1 antibody (NP137) in two distinct, toll-like receptor (TLR) 2/TLR3/TLR6-dependent, hepatic inflammatory mouse settings. We observe a clear anti-inflammatory activity indicating the proinflammatory impact of netrin-1 on several chemokines and Ly6C+ macrophages. CONCLUSIONS These results identify netrin-1 as an inflammation-inducible factor in the liver through an atypical mechanism as well as its contribution to hepatic inflammation.
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Affiliation(s)
- Romain Barnault
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Claire Verzeroli
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Carole Fournier
- Institute for Advanced Biosciences, Inserm U1209, University of Grenoble-Alpes, La Tronche, France
| | - Maud Michelet
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Anna Rita Redavid
- University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Apoptosis, Cancer and Development Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Ievgeniia Chicherova
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Marie-Laure Plissonnier
- University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Inserm U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Annie Adrait
- University of Grenoble-Alpes, Inserm, CEA, UMR BioSanté U1292, CNRS CEA FR2048, Grenoble, France
| | - Olga Khomich
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Fleur Chapus
- Single Cell Dynamics Group, Epigenetics and Stem Cell Biology Laboratory, National Institute of Environmental Health Sciences, Research Triangle Park, Durham, North Carolina, USA
| | - Mathieu Richaud
- University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Apoptosis, Cancer and Development Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Maëva Hervieu
- University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Apoptosis, Cancer and Development Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Veronika Reiterer
- Institute of Pathophysiology, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Julie Lucifora
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Birke Bartosch
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
| | - Michel Rivoire
- Léon Bérard Cancer Center, Lyon, France.,Université Lyon 1, Lyon, France
| | - Hesso Farhan
- Institute of Pathophysiology, Medical University of Innsbruck, Innsbruck, Austria
| | - Yohann Couté
- University of Grenoble-Alpes, Inserm, CEA, UMR BioSanté U1292, CNRS CEA FR2048, Grenoble, France
| | - Valbona Mirakaj
- Department of Anesthesiology and Intensive Care Medicine, University Hospital of Tuebingen, Eberhard-Karls University, Tuebingen, Germany
| | - Thomas Decaens
- Institute for Advanced Biosciences, Inserm U1209, University of Grenoble-Alpes, La Tronche, France
| | - Patrick Mehlen
- University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Apoptosis, Cancer and Development Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Benjamin Gibert
- University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Apoptosis, Cancer and Development Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France
| | - Fabien Zoulim
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France.,Service of Hepato-Gastroenterology, Hospices Civils de Lyon, Lyon, France
| | - Romain Parent
- Pathogenesis of Chronic Hepatitis B and C Laboratory - LabEx DEVweCAN, Inserm U1052, Cancer Research Centre of Lyon, Lyon, France.,University of Lyon, Lyon, France.,University Lyon 1, Institut des Sciences Pharmaceutiques et Biologiques, Lyon, France.,CNRS UMR5286, Lyon, France.,Centre Léon Bérard, Lyon, France
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2
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Singh D, Thakur S, Singh D, Buttar HS, Singh B, Arora S. Modulatory Effect of 4-(methylthio)butyl Isothiocyanate Isolated From Eruca Sativa Thell. on DMBA Induced Overexpression of Hypoxia and Glycolytic Pathway in Sprague-Dawley Female Rats. Front Pharmacol 2021; 12:728296. [PMID: 34447314 PMCID: PMC8383164 DOI: 10.3389/fphar.2021.728296] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 07/29/2021] [Indexed: 12/30/2022] Open
Abstract
4-(methylthio)butyl isothiocyanate (4-MTBITC) is a hydrolytic product from the plant Eruca sativa Thell. In the present study, we explored the anti-cancer effect of 4-MTBITC against 7,12-dimethylbenz [a] anthracene (DMBA) induced breast cancer. Hypoxic conditions were developed using a single dose of 60 mg/kg DMBA. Hepatic and renal parameters were increased along with antioxidants in cancer-bearing rats which were lowered with the treatment of 4-MTBITC. Further, it inhibited the up-regulation of glycolytic enzymes caused by DMBA. The hypoxia pathway was evaluated using RT-PCR and it was found that the 40 mg/kg doses of 4-MTBITC statistically lowered the expression of HIF-1α. Akt/mTOR signaling pathway was one of the major pathways involved in 4-MTBITC-induced cell growth arrest by western blotting. Amino acid profiling serum-free plasma revealed the downregulation of specific amino acids required for vital components of fast-growing cancer cells. 4-MTBITC reduced the levels of serine, arginine, alanine, asparagines, and glutamic acid. Histological examination also showed neoplastic growth following DMBA doses. 4-MTBITC treated rats showed less infiltration and normal physiology. Our findings for the first time demonstrated the potential therapeutic significance of 4-MTBITC on modulation of glycolytic enzymes and hypoxia pathway in female rats.
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Affiliation(s)
- Davinder Singh
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, India
| | - Sharad Thakur
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, India
| | - Drishtant Singh
- Department of Molecular Biology and Biochemistry, Guru Nanak Dev University, Amritsar, India
| | - Harpal Singh Buttar
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada
| | - Balbir Singh
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, India
| | - Saroj Arora
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, India
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3
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Singh S, Harmalkar DS, Choi Y, Lee K. Fructose-1,6-bisphosphatase Inhibitors: A Review of Recent (2000- 2017) Advances and Structure-Activity Relationship Studies. Curr Med Chem 2019; 26:5542-5563. [DOI: 10.2174/0929867325666180831133734] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/01/2018] [Accepted: 07/20/2018] [Indexed: 11/22/2022]
Abstract
:
Diabetes mellitus, commonly referred to as diabetes, is the 8th leading cause of
death worldwide. As of 2015, approximately 415 million people were estimated to be diabetic
worldwide, type 2 diabetes being the most common accounting for approximately 90-95% of
all diagnosed cases with increasing prevalence. Fructose-1,6-bisphosphatase is one of the important
therapeutic targets recently discovered to treat this chronic disease. In this focused
review, we have highlighted recent advances and structure-activity relationship studies in the
discovery and development of different fructose-1,6-bisphosphatase inhibitors reported since
the year 2000.
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Affiliation(s)
- Sarbjit Singh
- College of Pharmacy, Dongguk University-Seoul, Goyang, 10326, Korea
| | | | - Yongseok Choi
- College of Life Sciences and Biotechnology, Korea University, Seoul 02841, Korea
| | - Kyeong Lee
- College of Pharmacy, Dongguk University-Seoul, Goyang, 10326, Korea
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4
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Megarity CF, Abdel‐Aal Bettley H, Caraher MC, Scott KA, Whitehead RC, Jowitt TA, Gutierrez A, Bryce RA, Nolan KA, Stratford IJ, Timson DJ. Negative Cooperativity in NAD(P)H Quinone Oxidoreductase 1 (NQO1). Chembiochem 2019; 20:2841-2849. [DOI: 10.1002/cbic.201900313] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Indexed: 12/17/2022]
Affiliation(s)
- Clare F. Megarity
- School of Biological SciencesQueen's University BelfastMedical Biology Centre 97 Lisburn Road Belfast BT9 7BL UK
| | - Hoda Abdel‐Aal Bettley
- Manchester Pharmacy SchoolThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - M. Clare Caraher
- School of Biological SciencesQueen's University BelfastMedical Biology Centre 97 Lisburn Road Belfast BT9 7BL UK
- Manchester Pharmacy SchoolThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Katherine A. Scott
- Manchester Pharmacy SchoolThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Roger C. Whitehead
- Department of ChemistryThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Thomas A. Jowitt
- The Faculty of Life ScienceManchester Cancer Research Centre and the University of Manchester Oxford Road Manchester M13 9PT UK
| | - Aldo Gutierrez
- School of Science and TechnologyNottingham Trent University Clifton Campus Nottingham NG11 8NS UK
| | - Richard A. Bryce
- Manchester Pharmacy SchoolThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Karen A. Nolan
- Manchester Pharmacy SchoolThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - Ian J. Stratford
- Manchester Pharmacy SchoolThe University of Manchester Oxford Road Manchester M13 9PL UK
| | - David J. Timson
- School of Biological SciencesQueen's University BelfastMedical Biology Centre 97 Lisburn Road Belfast BT9 7BL UK
- School of Pharmacy and Biomolecular Sciences, Huxley BuildingUniversity of Brighton Lewes Road Brighton BN2 4GJ UK
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5
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Kumar S, Masison DC. Hsp70-nucleotide exchange factor (NEF) Fes1 has non-NEF roles in degradation of gluconeogenic enzymes and cell wall integrity. PLoS Genet 2019; 15:e1008219. [PMID: 31242183 PMCID: PMC6615629 DOI: 10.1371/journal.pgen.1008219] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 07/09/2019] [Accepted: 05/28/2019] [Indexed: 12/03/2022] Open
Abstract
Fes1 is a conserved armadillo repeat-containing Hsp70 nucleotide exchange factor important for growth at high temperature, proteasomal protein degradation and prion propagation. Depleting or mutating Fes1 induces a stress response and causes defects in these processes that are ascribed solely to disruption of Fes1 regulation of Hsp70. Here, we find Fes1 was essential for degradation of gluconeogenic enzymes by the vacuole import and degradation (Vid) pathway and for cell wall integrity (CWI), which is crucial for growth at high temperature. Unexpectedly, Fes1 mutants defective in physical or functional interaction with Hsp70 retained activities that support Vid and CWI. Fes1 and the Fes1 mutants bound to the Vid substrate Fbp1 in vitro and captured Slt2, a signaling kinase that regulates CWI, from cell lysates. Our data show that the armadillo domain of Fes1 binds proteins other than Hsp70, that Fes1 has important Hsp70-independent roles in the cell, and that major growth defects caused by depleting Fes1 are due to loss of these functions rather than to loss of Hsp70 regulation. We uncovered diverse functions of Fes1 beyond its defined role in regulating Hsp70, which points to possible multi-functionality among its conserved counterparts in other organisms or organelles. Fes1, a yeast homolog of human nucleotide exchange factor HspBP1, binds and regulates Hsp70, a universally conserved protein that helps maintain health of proteins in cells. Fes1 is believed to function only by helping Hsp70 release ADP and substrates and cells lacking Fes1 are sick. We find Fes1 is essential for protein degradation by a vacuolar pathway (Vid) and for cell wall integrity (CWI), and it interacts with a Vid substrate and a regulator of CWI. Fes1 mutants that cannot regulate Hsp70 can still support Vid and CWI, interact with proteins involved in these processes and restore cell health. Thus, Fes1 binds proteins other than Hsp70 and has important functions beyond regulating Hsp70 that are needed for optimal cell fitness.
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Affiliation(s)
- Shailesh Kumar
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel C. Masison
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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6
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Filimonov IS, Berzova AP, Barkhatov VI, Krivoshey AV, Trushkin NA, Vrzheshch PV. Negative Cooperativity in the Interaction of Prostaglandin H Synthase-1 with the Competitive Inhibitor Naproxen Can Be Described as the Interaction of a Non-competitive Inhibitor with Heterogeneous Enzyme Preparation. BIOCHEMISTRY (MOSCOW) 2018; 83:119-128. [PMID: 29618298 DOI: 10.1134/s0006297918020049] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The kinetic mechanism of the interaction of nonsteroidal anti-inflammatory drugs (NSAIDs) with their main pharmacological target, prostaglandin H synthase (PGHS), has not yet been established. We showed that inhibition of PGHS-1 from sheep vesicular glands by naproxen (a representative of NSAIDs) demonstrates a non-competitive character with respect to arachidonic acid and cannot be described within a framework of the commonly used kinetic schemes. However, it can be described by taking into account the negative cooperativity of naproxen binding to the cyclooxygenase active sites of the PGHS-1 homodimer (the first naproxen molecule forms a more stable complex (K1 = 0.1 µM) with the enzyme than the second naproxen molecule (K2 = 9.2 µM)). An apparent non-competitive interaction of PGHS-1 with naproxen is due to slow dissociation of the enzyme-inhibitor complexes. The same experimental data could also be described using commonly accepted kinetic schemes, assuming that naproxen interacts was a mixture of two enzyme species with the inhibition constants Kα = 0.05 µM and Kβ = 18.3 µM. Theoretical analysis and numerical calculations show that the phenomenon of kinetic convergence of these two models has a general nature: when K2 >> K1, the kinetic patterns (for transient kinetics and equilibrium state) generated by the cooperative model could be described by a scheme assuming the presence of two enzyme forms with the inhibition constants Kα = K1/2, Kβ = 2·K2. When K2 << K1, the cooperative model can be presented as a scheme with two inhibitor molecules simultaneously binding to the enzyme with the observed inhibition constant K (K = K1·K2). The assumption on the heterogeneity of the enzyme preparation in relation to its affinity to the inhibitor can be used instead of the assumption on the negative cooperativity of the enzyme-inhibitor interactions for convenient and easy practical description of such phenomena in enzymology, biotechnology, pharmacology, and other fields of science.
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Affiliation(s)
- I S Filimonov
- Lomonosov Moscow State University, International Biotechnological Center, Moscow, 119991, Russia
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7
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Liu GM, Zhang YM. Targeting FBPase is an emerging novel approach for cancer therapy. Cancer Cell Int 2018; 18:36. [PMID: 29556139 PMCID: PMC5845355 DOI: 10.1186/s12935-018-0533-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2017] [Accepted: 03/05/2018] [Indexed: 02/06/2023] Open
Abstract
Cancer is a leading cause of death in both developed and developing countries. Metabolic reprogramming is an emerging hallmark of cancer. Glucose homeostasis is reciprocally controlled by the catabolic glycolysis and anabolic gluconeogenesis pathways. Previous studies have mainly focused on catabolic glycolysis, but recently, FBPase, a rate-limiting enzyme in gluconeogenesis, was found to play critical roles in tumour initiation and progression in several cancer types. Here, we review recent ideas and discoveries that illustrate the clinical significance of FBPase expression in various cancers, the mechanism through which FBPase influences cancer, and the mechanism of FBPase silencing. Furthermore, we summarize some of the drugs targeting FBPase and discuss their potential use in clinical applications and the problems that remain unsolved.
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Affiliation(s)
- Gao-Min Liu
- Department of Hepatobiliary Surgery, Meizhou People's Hospital, No. 38 Huangtang Road, Meizhou, 514000 China
| | - Yao-Ming Zhang
- Department of Hepatobiliary Surgery, Meizhou People's Hospital, No. 38 Huangtang Road, Meizhou, 514000 China
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8
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Hardie DG. Keeping the home fires burning: AMP-activated protein kinase. J R Soc Interface 2018; 15:20170774. [PMID: 29343628 PMCID: PMC5805978 DOI: 10.1098/rsif.2017.0774] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 12/11/2017] [Indexed: 12/20/2022] Open
Abstract
Living cells obtain energy either by oxidizing reduced compounds of organic or mineral origin or by absorbing light. Whichever energy source is used, some of the energy released is conserved by converting adenosine diphosphate (ADP) to adenosine triphosphate (ATP), which are analogous to the chemicals in a rechargeable battery. The energy released by the conversion of ATP back to ADP is used to drive most energy-requiring processes, including cell growth, cell division, communication and movement. It is clearly essential to life that the production and consumption of ATP are always maintained in balance, and the AMP-activated protein kinase (AMPK) is one of the key cellular regulatory systems that ensures this. In eukaryotic cells (cells with nuclei and other internal membrane-bound structures, including human cells), most ATP is produced in mitochondria, which are thought to have been derived by the engulfment of oxidative bacteria by a host cell not previously able to use molecular oxygen. AMPK is activated by increasing AMP or ADP (AMP being generated from ADP whenever ADP rises) coupled with falling ATP. Relatives of AMPK are found in essentially all eukaryotes, and it may have evolved to allow the host cell to monitor the output of the newly acquired mitochondria and step their ATP production up or down according to the demand. Structural studies have illuminated how AMPK achieves the task of detecting small changes in AMP and ADP, despite the presence of much higher concentrations of ATP. Recently, it has been shown that AMPK can also sense the availability of glucose, the primary carbon source for most eukaryotic cells, via a mechanism independent of changes in AMP or ADP. Once activated by energy imbalance or glucose lack, AMPK modifies many target proteins by transferring phosphate groups to them from ATP. By this means, numerous ATP-producing processes are switched on (including the production of new mitochondria) and ATP-consuming processes are switched off, thus restoring energy homeostasis. Drugs that modulate AMPK have great potential in the treatment of metabolic disorders such as obesity and Type 2 diabetes, and even cancer. Indeed, some existing drugs such as metformin and aspirin, which were derived from traditional herbal remedies, appear to work, in part, by activating AMPK.
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Affiliation(s)
- D Grahame Hardie
- Division of Cell Signalling and Immunology, School of Life Sciences, University of Dundee, Dow Street, Dundee, DD1 5EH, UK
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9
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Patel SN, Parikh M, Lau-Cam CA. Impact of light ethanol intake and of taurine, separately and together, on pathways of glucose metabolism in the kidney of diabetic rats. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 803:279-303. [PMID: 25833505 DOI: 10.1007/978-3-319-15126-7_23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Sanket N Patel
- Department of Pharmaceutical Sciences, College of Pharmacy and Health Sciences, St. John's University, Jamaica, NY, USA
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10
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Bie J, Liu S, Li Z, Mu Y, Xu B, Shen Z. Discovery of novel indole derivatives as allosteric inhibitors of fructose-1,6-bisphosphatase. Eur J Med Chem 2014; 90:394-405. [PMID: 25461330 DOI: 10.1016/j.ejmech.2014.11.049] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2014] [Revised: 10/30/2014] [Accepted: 11/24/2014] [Indexed: 11/30/2022]
Abstract
A series of novel indole derivatives was designed and synthesized as inhibitors of fructose-1,6-bisphosphatase (FBPase). The most potent compound 14c was identified with an IC50 value of 0.10 μM by testing the inhibitory activity against recombinant human FBPase. The structure-activity relationships were investigated on the substitution at 4- and 5-position of the indole scaffold. The binding interactions of the title compounds at AMP binding site of FBPase were predicted using CDOCKER algorithm.
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Affiliation(s)
- Jianbo Bie
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing 100050, China
| | - Shuainan Liu
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing 100050, China
| | - Zhanmei Li
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing 100050, China
| | - Yongzhao Mu
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing 100050, China
| | - Bailing Xu
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing 100050, China.
| | - Zhufang Shen
- Beijing Key Laboratory of Active Substance Discovery and Druggability Evaluation, Institute of Materia Medica, Chinese Academy of Medical Sciences&Peking Union Medical College, Beijing 100050, China.
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11
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Ferrell JE, Ha SH. Ultrasensitivity part I: Michaelian responses and zero-order ultrasensitivity. Trends Biochem Sci 2014; 39:496-503. [PMID: 25240485 DOI: 10.1016/j.tibs.2014.08.003] [Citation(s) in RCA: 128] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Revised: 08/11/2014] [Accepted: 08/14/2014] [Indexed: 12/20/2022]
Abstract
Quantitative studies of signal transduction systems have shown that ultrasensitive responses - switch-like, sigmoidal input/output relationships - are commonplace in cell signaling. Ultrasensitivity is important for various complex signaling systems, including signaling cascades, bistable switches, and oscillators. In this first installment of a series on ultrasensitivity we survey the occurrence of ultrasensitive responses in signaling systems. We review why the simplest mass action systems exhibit Michaelian responses, and then move on to zero-order ultrasensitivity, a phenomenon that occurs when signaling proteins are operating near saturation. We also discuss the physiological relevance of zero-order ultrasensitivity to cellular regulation.
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Affiliation(s)
- James E Ferrell
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA.
| | - Sang Hoon Ha
- Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305-5174, USA
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Asenjo JL, Ludwig HC, Droppelmann CA, Cárcamo JG, Concha II, Yáñez AJ, Cárdenas ML, Cornish-Bowden A, Slebe JC. Subunit interactions in pig-kidney fructose-1,6-bisphosphatase: Binding of substrate induces a second class of site with lowered affinity and catalytic activity. Biochim Biophys Acta Gen Subj 2014; 1840:1798-807. [DOI: 10.1016/j.bbagen.2013.12.027] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 11/28/2013] [Accepted: 12/23/2013] [Indexed: 10/25/2022]
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Gao Y, Shen L, Honzatko RB. Central cavity of fructose-1,6-bisphosphatase and the evolution of AMP/fructose 2,6-bisphosphate synergism in eukaryotic organisms. J Biol Chem 2014; 289:8450-61. [PMID: 24436333 DOI: 10.1074/jbc.m114.548586] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The effects of AMP and fructose 2,6-bisphosphate (Fru-2,6-P2) on porcine fructose-1,6-bisphosphatase (pFBPase) and Escherichia coli FBPase (eFBPase) differ in three respects. AMP/Fru-2,6-P2 synergism in pFBPase is absent in eFBPase. Fru-2,6-P2 induces a 13° subunit pair rotation in pFBPase but no rotation in eFBPase. Hydrophilic side chains in eFBPase occupy what otherwise would be a central aqueous cavity observed in pFBPase. Explored here is the linkage of AMP/Fru-2,6-P2 synergism to the central cavity and the evolution of synergism in FBPases. The single mutation Ser(45) → His substantially fills the central cavity of pFBPase, and the triple mutation Ser(45) → His, Thr(46) → Arg, and Leu(186) → Tyr replaces porcine with E. coli type side chains. Both single and triple mutations significantly reduce synergism while retaining other wild-type kinetic properties. Similar to the effect of Fru-2,6-P2 on eFBPase, the triple mutant of pFBPase with bound Fru-2,6-P2 exhibits only a 2° subunit pair rotation as opposed to the 13° rotation exhibited by the Fru-2,6-P2 complex of wild-type pFBPase. The side chain at position 45 is small in all available eukaryotic FBPases but large and hydrophilic in bacterial FBPases, similar to eFBPase. Sequence information indicates the likelihood of synergism in the FBPase from Leptospira interrogans (lFBPase), and indeed recombinant lFBPase exhibits AMP/Fru-2,6-P2 synergism. Unexpectedly, however, AMP also enhances Fru-6-P binding to lFBPase. Taken together, these observations suggest the evolution of AMP/Fru-2,6-P2 synergism in eukaryotic FBPases from an ancestral FBPase having a central aqueous cavity and exhibiting synergistic feedback inhibition by AMP and Fru-6-P.
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Affiliation(s)
- Yang Gao
- From the Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa 50011
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Hasenour CM, Ridley DE, Hughey CC, James FD, Donahue EP, Shearer J, Viollet B, Foretz M, Wasserman DH. 5-Aminoimidazole-4-carboxamide-1-β-D-ribofuranoside (AICAR) effect on glucose production, but not energy metabolism, is independent of hepatic AMPK in vivo. J Biol Chem 2014; 289:5950-9. [PMID: 24403081 DOI: 10.1074/jbc.m113.528232] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Metabolic stress, as well as several antidiabetic agents, increases hepatic nucleotide monophosphate (NMP) levels, activates AMP-activated protein kinase (AMPK), and suppresses glucose production. We tested the necessity of hepatic AMPK for the in vivo effects of an acute elevation in NMP on metabolism. 5-Aminoimidazole-4-carboxamide 1-β-D-ribofuranoside (AICAR; 8 mg·kg(-1)·min(-1))-euglycemic clamps were performed to elicit an increase in NMP in wild type (α1α2(lox/lox)) and liver-specific AMPK knock-out mice (α1α2(lox/lox) + Albcre) in the presence of fixed glucose. Glucose kinetics were equivalent in 5-h fasted α1α2(lox/lox) and α1α2(lox/lox) + Albcre mice. AMPK was not required for AICAR-mediated suppression of glucose production and increased glucose disappearance. These results demonstrate that AMPK is unnecessary for normal 5-h fasting glucose kinetics and AICAR-mediated inhibition of glucose production. Moreover, plasma fatty acids and triglycerides also decreased independently of hepatic AMPK during AICAR administration. Although the glucoregulatory effects of AICAR were shown to be independent of AMPK, these studies provide in vivo support for the AMPK energy sensor paradigm. AICAR reduced hepatic energy charge by ∼20% in α1α2(lox/lox), which was exacerbated by ∼2-fold in α1α2(lox/lox) + Albcre. This corresponded to a ∼6-fold rise in AMP/ATP in α1α2(lox/lox) + Albcre. Consistent with the effects on adenine nucleotides, maximal mitochondrial respiration was ∼30% lower in α1α2(lox/lox) + Albcre than α1α2(lox/lox) livers. Mitochondrial oxidative phosphorylation efficiency was reduced by 25%. In summary, these results demonstrate that the NMP capacity to inhibit glucose production in vivo is independent of liver AMPK. In contrast, AMPK promotes mitochondrial function and protects against a more precipitous fall in ATP during AICAR administration.
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Cornish-Bowden A. The physiological significance of negative cooperativity revisited. J Theor Biol 2013; 319:144-7. [DOI: 10.1016/j.jtbi.2012.12.010] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2012] [Revised: 11/06/2012] [Accepted: 12/07/2012] [Indexed: 10/27/2022]
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Jiang P, Ventura AC, Ninfa AJ. Characterization of the reconstituted UTase/UR-PII-NRII-NRI bicyclic signal transduction system that controls the transcription of nitrogen-regulated (Ntr) genes in Escherichia coli. Biochemistry 2012; 51:9045-57. [PMID: 23088566 DOI: 10.1021/bi300575j] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A reconstituted UTase/UR-PII-NRII-NRI bicyclic cascade regulated PII uridylylation and NRI phosphorylation in response to glutamine. We examined the sensitivity and robustness of the responses of the individual cycles and of the bicyclic system. The sensitivity of the glutamine response of the upstream UTase/UR-PII monocycle depended upon the PII concentration, and we show that PII exerted substrate inhibition of the UTase activity of UTase/UR, potentially contributing to this dependence of sensitivity on PII. In the downstream NRII-NRI monocycle, PII controlled NRI phosphorylation state, and the response to PII was hyperbolic at both saturating and unsaturating NRI concentration. As expected from theory, the level of NRI∼P produced by the NRII-NRI monocycle was robust to changes in the NRII or NRI concentrations when NRI was in excess over NRII, as long as the NRII concentration was above a threshold value, an example of absolute concentration robustness (ACR). Because of the parameters of the system, at physiological protein levels and ratios of NRI to NRII, the level of NRI∼P depended upon both protein concentrations. In bicyclic UTase/UR-PII-NRII-NRI systems, the NRI phosphorylation state response to glutamine was always hyperbolic, regardless of the PII concentration or sensitivity of the upstream UTase/UR-PII cycle. In these bicyclic systems, NRI phosphorylation state was only robust to variation in the PII/NRII ratio within a narrow range; when PII was in excess NRI∼P was low, and when NRII was in excess NRI phosphorylation was elevated, throughout the physiological range of glutamine concentrations. Our results show that the bicyclic system produced a graded response of NRI phosphorylation to glutamine under a range of conditions, and that under most conditions the response of NRI phosphorylation state to glutamine levels depended on the concentrations of NRI, NRII, and PII.
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Affiliation(s)
- Peng Jiang
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109-0606, United States
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Jiang P, Ninfa AJ. A Source of Ultrasensitivity in the Glutamine Response of the Bicyclic Cascade System Controlling Glutamine Synthetase Adenylylation State and Activity in Escherichia coli. Biochemistry 2011; 50:10929-40. [DOI: 10.1021/bi201410x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peng Jiang
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109,
United States
| | - Alexander J. Ninfa
- Department of Biological Chemistry, University of Michigan Medical School, Ann Arbor, Michigan 48109,
United States
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Probing a family GH11 endo-β-1,4-xylanase inhibition mechanism by phenolic compounds: Role of functional phenolic groups. ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.molcatb.2011.05.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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RLIP76, a glutathione-conjugate transporter, plays a major role in the pathogenesis of metabolic syndrome. PLoS One 2011; 6:e24688. [PMID: 21931813 PMCID: PMC3172288 DOI: 10.1371/journal.pone.0024688] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2011] [Accepted: 08/17/2011] [Indexed: 01/11/2023] Open
Abstract
PURPOSE Characteristic hypoglycemia, hypotriglyceridemia, hypocholesterolemia, lower body mass, and fat as well as pronounced insulin-sensitivity of RLIP76⁻/⁻ mice suggested to us the possibility that elevation of RLIP76 in response to stress could itself elicit metabolic syndrome (MSy). Indeed, if it were required for MSy, drugs used to treat MSy should have no effect on RLIP76⁻/⁻ mice. RESEARCH DESIGN AND METHODS Blood glucose (BG) and lipid measurements were performed in RLIP76⁺/⁺ and RLIP76⁻/⁻ mice, using Ascensia Elite Glucometer® for glucose and ID Labs kits for cholesterol and triglycerides assays. The ultimate effectors of gluconeogenesis are the three enzymes: PEPCK, F-1,6-BPase, and G6Pase, and their expression is regulated by PPARγ and AMPK. The activity of these enzymes was tested by protocols standardized by us. Expressions of RLIP76, PPARα, PPARγ, HMGCR, pJNK, pAkt, and AMPK were performed by Western-blot and tissue staining. RESULTS The concomitant activation of AMPK and PPARγ by inhibiting transport activity of RLIP76, despite inhibited activity of key glucocorticoid-regulated hepatic gluconeogenic enzymes like PEPCK, G6Pase and F-1,6-BP in RLIP76⁻/⁻ mice, is a salient finding of our studies. The decrease in RLIP76 protein expression by rosiglitazone and metformin is associated with an up-regulation of PPARγ and AMPK. CONCLUSIONS/SIGNIFICANCE All four drugs, rosiglitazone, metformin, gemfibrozil and atorvastatin failed to affect glucose and lipid metabolism in RLIP76⁻/⁻ mice. Studies confirmed a model in which RLIP76 plays a central role in the pathogenesis of MSy and RLIP76 loss causes profound and global alterations of MSy signaling functions. RLIP76 is a novel target for single-molecule therapeutics for metabolic syndrome.
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Köksal M, Zimmer I, Schnitzler JP, Christianson DW. Structure of isoprene synthase illuminates the chemical mechanism of teragram atmospheric carbon emission. J Mol Biol 2010; 402:363-73. [PMID: 20624401 DOI: 10.1016/j.jmb.2010.07.009] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Revised: 07/02/2010] [Accepted: 07/06/2010] [Indexed: 11/29/2022]
Abstract
The X-ray crystal structure of recombinant PcISPS (isoprene synthase from gray poplar hybrid Populus×canescens) has been determined at 2.7 Å resolution, and the structure of its complex with three Mg(2+) and the unreactive substrate analogue dimethylallyl-S-thiolodiphosphate has been determined at 2.8 Å resolution. Analysis of these structures suggests that the generation of isoprene from substrate dimethylallyl diphosphate occurs via a syn-periplanar elimination mechanism in which the diphosphate-leaving group serves as a general base. This chemical mechanism is responsible for the annual atmospheric emission of 100 Tg of isoprene by terrestrial plant life. Importantly, the PcISPS structure promises to guide future protein engineering studies, potentially leading to hydrocarbon fuels and products that do not rely on traditional petrochemical sources.
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Affiliation(s)
- Mustafa Köksal
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, 231 South 34th Street, Philadelphia, PA 19104-6323, USA
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21
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Burenina EA. Fructose bisphosphatase of cestodes of Bothriocephalus scorpii. J EVOL BIOCHEM PHYS+ 2010. [DOI: 10.1134/s0022093010020031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Awasthi S, Singhal SS, Yadav S, Singhal J, Vatsyayan R, Zajac E, Luchowski R, Borvak J, Gryczynski K, Awasthi YC. A central role of RLIP76 in regulation of glycemic control. Diabetes 2010; 59:714-25. [PMID: 20007934 PMCID: PMC2828645 DOI: 10.2337/db09-0911] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Pathology associated with oxidative stress frequently results in insulin resistance. Glutathione (GSH) and GSH-linked metabolism is a primary defense against oxidative stress. Electrophilic lipid alkenals, such as 4-hydroxy-t-2-nonenal (4HNE), generated during oxidative stress are metabolized primarily to glutathione electrophile (GS-E) conjugates. Recent studies show that RLIP76 is the primary GS-E conjugate transporter in cells, and a regulator of oxidative-stress response. Because RLIP76(-/-) mice are hypoglycemic, we studied the role of RLIP76 in insulin resistance. RESEARCH DESIGN AND METHODS Blood glucose, insulin, lipid measurements, and hyperinsulinemic-euglycemic and hyperglycemic clamp experiments were performed in RLIP76(+/+) and RLIP76(-/-) C57B mice, using Institutional Animal Care and Use Committee-approved protocols. Time-resolved three-dimensional confocal fluorescence microscopy was used to study insulin endocytosis. RESULTS The plasma insulin/glucose ratio was ordered RLIP76(-/-) < RLIP76(+/-) < RLIP76(+/+); administration of purified RLIP76 in proteoliposomes to RLIP76(+/+) animals further increased this ratio. RLIP76 was induced by oxidative or hyperglycemic stress; the concomitant increase in insulin endocytosis was completely abrogated by inhibiting the transport activity of RLIP76. Hydrocortisone could transiently correct hypoglycemia in RLIP76(-/-) animals, despite inhibited activity of key glucocorticoid-regulated hepatic gluconeogenic enzymes, phosphoenolpyruvate carboxykinase, glucose-6-phosphatase, and fructose 1,6-bisphosphatase, in RLIP76(-/-). CONCLUSIONS The GS-E conjugate transport activity of RLIP76 mediates insulin resistance by enhancing the rate of clathrin-dependent endocytosis of insulin. Because RLIP76 is induced by oxidative stress, it could play a role in insulin resistance seen in pathological conditions characterized by increased oxidative stress.
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Affiliation(s)
- Sanjay Awasthi
- Department of Molecular Biology & Immunology, University of North Texas Health Science Center, Fort Worth, Texas, USA.
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Hines JK, Chen X, Nix JC, Fromm HJ, Honzatko RB. Structures of mammalian and bacterial fructose-1,6-bisphosphatase reveal the basis for synergism in AMP/fructose 2,6-bisphosphate inhibition. J Biol Chem 2007; 282:36121-31. [PMID: 17933867 DOI: 10.1074/jbc.m707302200] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fructose-1,6-bisphosphatase (FBPase) operates at a control point in mammalian gluconeogenesis, being inhibited synergistically by fructose 2,6-bisphosphate (Fru-2,6-P(2)) and AMP. AMP and Fru-2,6-P(2) bind to allosteric and active sites, respectively, but the mechanism responsible for AMP/Fru-2,6-P(2) synergy is unclear. Demonstrated here for the first time is a global conformational change in porcine FBPase induced by Fru-2,6-P(2) in the absence of AMP. The Fru-2,6-P(2) complex exhibits a subunit pair rotation of 13 degrees from the R-state (compared with the 15 degrees rotation of the T-state AMP complex) with active site loops in the disengaged conformation. A three-state thermodynamic model in which Fru-2,6-P(2) drives a conformational change to a T-like intermediate state can account for AMP/Fru-2,6-P(2) synergism in mammalian FBPases. AMP and Fru-2,6-P(2) are not synergistic inhibitors of the Type I FBPase from Escherichia coli, and consistent with that model, the complex of E. coli FBPase with Fru-2,6-P(2) remains in the R-state with dynamic loops in the engaged conformation. Evidently in porcine FBPase, the actions of AMP at the allosteric site and Fru-2,6-P(2) at the active site displace engaged dynamic loops by distinct mechanisms, resulting in similar quaternary end-states. Conceivably, Type I FBPases from all eukaryotes may undergo similar global conformational changes in response to Fru-2,6-P(2) ligation.
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Affiliation(s)
- Justin K Hines
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, Iowa 50011, USA
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Ludwig HC, Pardo FN, Asenjo JL, Maureira MA, Yañez AJ, Slebe JC. Unraveling multistate unfolding of pig kidney fructose-1,6-bisphosphatase using single tryptophan mutants. FEBS J 2007; 274:5337-49. [PMID: 17894826 DOI: 10.1111/j.1742-4658.2007.06059.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Pig kidney fructose-1,6-bisphosphatase is a homotetrameric enzyme which does not contain tryptophan. In a previous report the guanidine hydrochloride-induced unfolding of the enzyme has been described as a multistate process [Reyes, A. M., Ludwig, H. C., Yañez, A. J., Rodriguez, P. H and Slebe, J. C. (2003) Biochemistry 42, 6956-6964]. To monitor spectroscopically the unfolding transitions, four mutants were constructed containing a single tryptophan residue either near the C1-C2 or the C1-C4 intersubunit interface of the tetramer. The mutants were shown to retain essentially all of the structural and kinetic properties of the enzyme isolated from pig kidney. The enzymatic activity, intrinsic fluorescence, size-exclusion chromatographic profiles and 1-anilinonaphthalene-8-sulfonate binding by the mutants were studied under unfolding equilibrium conditions. The unfolding profiles were multisteps, and formation of hydrophobic structures was detected. The enzymatic activity of wild-type and mutant FBPases as a function of guanidine hydrochloride concentration showed an initial enhancement (maximum approximately 30%) followed by a biphasic decay. The activity and fluorescence results indicate that these transitions involve conformational changes in the fructose-1,6-bisphosphate and AMP domains. The representation of intrinsic fluorescence data as a 'phase diagram' reveals the existence of five intermediates, including two catalytically active intermediates that have not been previously described, and provides the first spectroscopic evidence for the formation of dimers. The intrinsic fluorescence unfolding profiles indicate that the dimers are formed by selective disruption of the C1-C2 interface.
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Affiliation(s)
- Heide C Ludwig
- Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
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Horecker BL, Melloni E, Pontremoli S. Fructose 1,6-bisphosphatase: properties of the neutral enzyme and its modification by proteolytic enzymes. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 42:193-226. [PMID: 236638 DOI: 10.1002/9780470122877.ch4] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Buchanan BB, Arnon DI. Ferredoxins: chemistry and function in photosynthesis, nitrogen fixation, and fermentative metabolism. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 33:119-76. [PMID: 4393906 DOI: 10.1002/9780470122785.ch3] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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Tejwani GA. Regulation of fructose-bisphosphatase activity. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 54:121-94. [PMID: 6303063 DOI: 10.1002/9780470122990.ch3] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Hue L. The role of futile cycles in the regulation of carbohydrate metabolism in the liver. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 52:247-331. [PMID: 6261536 DOI: 10.1002/9780470122976.ch4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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Stadtman ER. Allosteric regulation of enzyme activity. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 28:41-154. [PMID: 5334065 DOI: 10.1002/9780470122730.ch2] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Dougherty MJ, Boyd JM, Downs DM. Inhibition of fructose-1,6-bisphosphatase by aminoimidazole carboxamide ribotide prevents growth of Salmonella enterica purH mutants on glycerol. J Biol Chem 2006; 281:33892-9. [PMID: 16987812 DOI: 10.1074/jbc.m604429200] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enzyme fructose-1,6-bisphosphatase (FBP) is key regulatory point in gluconeogenesis. Mutants of Salmonella enterica lacking purH accumulate 5-amino-4-imidazole carboxamide ribotide (AICAR) and are unable to utilize glycerol as sole carbon and energy sources. The work described here demonstrates this lack of growth is due to inhibition of FBP by AICAR. Mutant alleles of fbp that restore growth on glycerol encode proteins resistant to inhibition by AICAR and the allosteric regulator AMP. This is the first report of biochemical characterization of substitutions causing AMP resistance in a bacterial FBP. Inhibition of FBP activity by AICAR occurs at physiologically relevant concentrations and may represent a form of regulation of gluconeogenic flux in Salmonella enterica.
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Affiliation(s)
- Michael J Dougherty
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706, USA
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Seiyama A. Virtual cooperativity in myoglobin oxygen saturation curve in skeletal muscle in vivo. DYNAMIC MEDICINE : DM 2006; 5:3. [PMID: 16430787 PMCID: PMC1397806 DOI: 10.1186/1476-5918-5-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/23/2005] [Accepted: 01/24/2006] [Indexed: 11/26/2022]
Abstract
Background Myoglobin (Mb) is the simplest monomeric hemoprotein and its physicochemical properties including reversible oxygen (O2)binding in aqueous solution are well known. Unexpectedly, however, its physiological role in intact muscle has not yet been established in spite of the fact that the role of the more complex tetrameric hemoprotein, hemoglobin (Hb), in red cells is well established. Here, I report my new findings on an overlooked property of skeletal Mb. Methods I directly observed the oxygenation of Mb in perfused rat skeletal muscle under various states of tissue respiration. A computer-controlled rapid scanning spectrophotometer was used to measure the oxygenation of Mb in the transmission mode. The light beam was focused on the thigh (quadriceps) through a 5-mm-diameter light guide. The transmitted light was conducted to the spectrophotometer through another 5-mm-diameter light guide. Visible difference spectra in the range of 500–650 nm were recorded when O2 uptake in the hindlimb muscle reached a constant value after every stepwise change in the O2 concentration of the buffer. Results The O2 dissociation curve (ODC) of Mb, when the effluent buffer O2 pressure was used as the abscissa, was of a sigmoid shape under normal and increased respiratory conditions whereas it was of rectangular hyperbolic shape under a suppressed respiratory condition. The dissociation curve was shifted toward the right and became more sigmoid with an increase in tissue respiration activity. These observations indicate that an increase in O2 demand in tissues makes the O2 saturation of Mb more sensitive to O2 pressure change in the capillaries and enhances the Mb-mediated O2 transfer from Hb to cytochrome oxidase (Cyt. aa3), especially under heavy O2 demands. Conclusion The virtual cooperativity and O2 demand-dependent shifts of the ODC may provide a basis for explaining why Mb has been preserved as monomer during molecular evolution.
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Affiliation(s)
- Akitoshi Seiyama
- Division of Physiology and Biosignaling, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Reyes AM, Ludwig HC, Yañez AJ, Rodríguez PH, Slebe JC. Nativelike intermediate on the unfolding pathway of pig kidney fructose-1,6-bisphosphatase. Biochemistry 2003; 42:6956-64. [PMID: 12795590 DOI: 10.1021/bi034203m] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The unfolding and dissociation of the tetrameric enzyme fructose-1,6-bisphosphatase from pig kidney by guanidine hydrochloride have been investigated at equilibrium by monitoring enzyme activity, ANS binding, intrinsic (tyrosine) protein fluorescence, exposure of thiol groups, fluorescence of extrinsic probes (AEDANS, MIANS), and size-exclusion chromatography. The unfolding is a multistate process involving as the first intermediate a catalytically inactive tetramer. The evidence that indicates the existence of this intermediate is as follows: (1) the loss of enzymatic activity and the concomitant increase of ANS binding, at low concentrations of Gdn.HCl (midpoint at 0.75 M), are both protein concentration independent, and (2) the enzyme remains in a tetrameric state at 0.9 M Gdn.HCl as shown by size-exclusion chromatography. At slightly higher Gdn.HCl concentrations the inactive tetramer dissociates to a compact dimer which is prone to aggregate. Further evidence for dissociation of tetramers to dimers and of dimers to monomers comes from the concentration dependence of AEDANS-labeled enzyme anisotropy data. Above 2.3 M Gdn.HCl the change of AEDANS anisotropy is concentration independent, indicative of monomer unfolding, which also is detected by a red shift of MIANS-labeled enzyme emission. At Gdn.HCl concentrations higher than 3.0 M, the protein elutes from the size-exclusion column as a single peak, with a retention volume smaller than that of the native protein, corresponding to the completely unfolded monomer. In the presence of its cofactor Mg(2+), the denaturated enzyme could be successfully reconstituted into the active enzyme with a yield of approximately 70-90%. Refolding kinetic data indicate that rapid refolding and reassociation of the monomers into a nativelike tetramer and reactivation of the tetramer are sequential events, the latter involving slow and small conformational rearrangements in the refolded enzyme.
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Affiliation(s)
- Alejandro M Reyes
- Instituto de Bioquímica, Facultad de Ciencias, Universidad Austral de Chile, Casilla 567, Valdivia, Chile
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Wright SW, Carlo AA, Danley DE, Hageman DL, Karam GA, Mansour MN, McClure LD, Pandit J, Schulte GK, Treadway JL, Wang IK, Bauer PH. 3-(2-carboxyethyl)-4,6-dichloro-1H-indole-2-carboxylic acid: an allosteric inhibitor of fructose-1,6-bisphosphatase at the AMP site. Bioorg Med Chem Lett 2003; 13:2055-8. [PMID: 12781194 DOI: 10.1016/s0960-894x(03)00310-x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
3-(2-Carboxyethyl)-4,6-dichloro-1H-indole-2-carboxylic acid (MDL-29951), an antagonist of the glycine site of the NMDA receptor, has been found to be an allosteric inhibitor of the enzyme fructose 1,6-bisphosphatase. The compound binds at the AMP regulatory site by X-ray crystallography. This represents a new approach to inhibition of fructose 1,6-bisphosphatase and serves as a lead for further drug design.
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Affiliation(s)
- Stephen W Wright
- Pfizer Central Research, Eastern Point Road, Box 8220-3141, Groton, CT 06340, USA.
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37
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Choe JY, Nelson SW, Fromm HJ, Honzatko RB. Interaction of Tl+ with product complexes of fructose-1,6-bisphosphatase. J Biol Chem 2003; 278:16008-14. [PMID: 12595529 DOI: 10.1074/jbc.m212394200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Fructose-1,6-bisphosphatase requires divalent cations (Mg2+, Mn2+, or Zn2+) for catalysis, but a diverse set of monovalent cations (K+, Tl+, Rb+, or NH(4)(+)) will further enhance enzyme activity. Here, the interaction of Tl+ with fructose-1,6-bisphosphatase is explored under conditions that support catalysis. On the basis of initial velocity kinetics, Tl+ enhances catalysis by 20% with a K(a) of 1.3 mm and a Hill coefficient near unity. Crystal structures of enzyme complexes with Mg2+, Tl+, and reaction products, in which the concentration of Tl+ is 1 mm or less, reveal Mg2+ at metal sites 1, 2, and 3 of the active site, but little or no bound Tl+. Intermediate concentrations of Tl+ (5-20 mm) displace Mg2+ from site 3 and the 1-OH group of fructose 6-phosphate from in-line geometry with respect to bound orthophosphate. Loop 52-72 appears in a new conformational state, differing from its engaged conformation by disorder in residues 61-69. Tl+ does not bind to metal sites 1 or 2 in the presence of Mg2+, but does bind to four other sites with partial occupancy. Two of four Tl+ sites probably represent alternative binding sites for the site 3 catalytic Mg2+, whereas the other sites could play roles in monovalent cation activation.
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Affiliation(s)
- Jun-Yong Choe
- Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, Ames, IA 50011, USA
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38
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Wright SW, Carlo AA, Carty MD, Danley DE, Hageman DL, Karam GA, Levy CB, Mansour MN, Mathiowetz AM, McClure LD, Nestor NB, McPherson RK, Pandit J, Pustilnik LR, Schulte GK, Soeller WC, Treadway JL, Wang IK, Bauer PH. Anilinoquinazoline inhibitors of fructose 1,6-bisphosphatase bind at a novel allosteric site: synthesis, in vitro characterization, and X-ray crystallography. J Med Chem 2002; 45:3865-77. [PMID: 12190310 DOI: 10.1021/jm010496a] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The synthesis and in vitro structure-activity relationships (SAR) of a novel series of anilinoquinazolines as allosteric inhibitors of fructose-1,6-bisphosphatase (F16Bpase) are reported. The compounds have a different SAR as inhibitors of F16Bpase than anilinoquinazolines previously reported. Selective inhibition of F16Bpase can be attained through the addition of appropriate polar functional groups at the quinazoline 2-position, thus separating the F16Bpase inhibitory activity from the epidermal growth factor receptor tyrosine kinase inhibitory activity previously observed with similar structures. The compounds have been found to bind at a symmetry-repeated novel allosteric site at the subunit interface of the enzyme. Inhibition is brought about by binding to a loop comprised of residues 52-72, preventing the necessary participation of these residues in the assembly of the catalytic site. Mutagenesis studies have identified the key amino acid residues in the loop that are required for inhibitor recognition and binding.
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Affiliation(s)
- Stephen W Wright
- Pfizer Central Research, Eastern Point Road, Groton, Connecticut 06340, USA.
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39
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Kelley-Loughnane N, Biolsi SA, Gibson KM, Lu G, Hehir MJ, Phelan P, Kantrowitz ER. Purification, kinetic studies, and homology model of Escherichia coli fructose-1,6-bisphosphatase. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1594:6-16. [PMID: 11825604 DOI: 10.1016/s0167-4838(01)00261-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Previous kinetic characterization of Escherichia coli fructose 1,6-bisphosphatase (FBPase) was performed on enzyme with an estimated purity of only 50%. Contradictory kinetic properties of the partially purified E. coli FBPase have been reported in regard to AMP cooperativity and inactivation by fructose-2,6-bisphosphate. In this investigation, a new purification for E. coli FBPase has been devised yielding enzyme with purity levels as high as 98%. This highly purified E. coli FBPase was characterized and the data compared to that for the pig kidney enzyme. Also, a homology model was created based upon the known three-dimensional structure of the pig kidney enzyme. The kcat of the E. coli FBPase was 14.6 s(-1) as compared to 21 s(-1) for the pig kidney enzyme, while the K(m) of the E. coli enzyme was approximately 10-fold higher than that of the pig kidney enzyme. The concentration of Mg2+ required to bring E. coli FBPase to half maximal activity was estimated to be 0.62 mM Mg2+, which is twice that required for the pig kidney enzyme. Unlike the pig kidney enzyme, the Mg2+ activation of the E. coli FBPase is not cooperative. AMP inhibition of mammalian FBPases is cooperative with a Hill coefficient of 2; however, the E. coli FBPase displays no cooperativity. Although cooperativity is not observed, the E. coli and pig kidney enzymes show similar AMP affinity. The quaternary structure of the E. coli enzyme is tetrameric, although higher molecular mass aggregates were also observed. The homology model of the E. coli enzyme indicated slight variations in the ligand-binding pockets compared to the pig kidney enzyme. The homology model of the E. coli enzyme also identified significant changes in the interfaces between the subunits, indicating possible changes in the path of communication of the allosteric signal.
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Affiliation(s)
- Nancy Kelley-Loughnane
- Department of Chemistry, Boston College, Merkert Chemistry Center, 140 Commonwealth Avenue, Chestnut Hill, MA 02467, USA
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40
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Krusteva NG, Tomova NG, Georgieva MA. Allosteric regulation of NAD(NADP)-dependent glyceraldehyde-3-phosphate dehydrogenase fromChlorellaby α-amino acids, dithiothreitol and ATP. FEBS Lett 2001. [DOI: 10.1016/0014-5793(84)80474-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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41
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Kelley-Loughnane N, Kantrowitz ER. AMP inhibition of pig kidney fructose-1,6-bisphosphatase. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1548:66-71. [PMID: 11451439 DOI: 10.1016/s0167-4838(01)00218-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Lys-112 and Tyr-113 in pig kidney fructose-1,6-bisphosphatase (FBPase) make direct interactions with AMP in the allosteric binding site. Both residues interact with the phosphate moiety of AMP while Tyr-113 also interacts with the 3'-hydroxyl of the ribose ring. The role of these two residues in AMP binding and allosteric inhibition was investigated. Site-specific mutagenesis was used to convert Lys-112 to glutamine (K112Q) and Tyr-113 to phenylalanine (Y113F). These amino acid substitutions result in small alterations in k(cat) and increases in K(m). However, both the K112Q and Y113F enzymes show alterations in Mg(2+) affinity and dramatic reductions in AMP affinity. For both mutant enzymes, the AMP concentration required to reduced the enzyme activity by one-half, [AMP](0.5), was increased more than a 1000-fold as compared to the wild-type enzyme. The K112Q enzyme also showed a 10-fold reduction in affinity for Mg(2+). Although the allosteric site is approximately 28 A from the metal binding sites, which comprise part of the active site, these site-specific mutations in the AMP site influence metal binding and suggest a direct connection between the allosteric and the active sites.
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Affiliation(s)
- N Kelley-Loughnane
- Department of Chemistry, Boston College, Merkert Chemistry Center, Chestnut Hill, MA 02467, USA
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42
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Choe JY, Fromm HJ, Honzatko RB. Crystal structures of fructose 1,6-bisphosphatase: mechanism of catalysis and allosteric inhibition revealed in product complexes. Biochemistry 2000; 39:8565-74. [PMID: 10913263 DOI: 10.1021/bi000574g] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Crystal structures of metal-product complexes of fructose 1, 6-bisphosphatase (FBPase) reveal competition between AMP and divalent cations. In the presence of AMP, the Zn(2+)-product and Mg(2+)-product complexes have a divalent cation present only at one of three metal binding sites (site 1). The enzyme is in the T-state conformation with a disordered loop of residues 52-72 (loop 52-72). In the absence of AMP, the enzyme crystallizes in the R-state conformation, with loop 52-72 associated with the active site. In structures without AMP, three metal-binding sites are occupied by Zn(2+) and two of three metal sites (sites 1 and 2) by Mg(2+). Evidently, the association of AMP with FBPase disorders loop 52-72, the consequence of which is the release of cations from two of three metal binding sites. In the Mg(2+) complexes (but not the Zn(2+) complexes), the 1-OH group of fructose 6-phosphate (F6P) coordinates to the metal at site 1 and is oriented for a nucleophilic attack on the bound phosphate molecule. A mechanism is presented for the forward reaction, in which Asp74 and Glu98 together generate a hydroxide anion coordinated to the Mg(2+) at site 2, which then displaces F6P. Development of negative charge on the 1-oxygen of F6P is stabilized by its coordination to the Mg(2+) at site 1.
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Affiliation(s)
- J Y Choe
- Department of Biochemistry, Iowa State University, Ames 50011, USA
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43
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Sawada M, Mitsui Y, Sugiya H, Furuyama S. Ribose 1,5-bisphosphate is a putative regulator of fructose 6-phosphate/fructose 1,6-bisphosphate cycle in liver. Int J Biochem Cell Biol 2000; 32:447-54. [PMID: 10762070 DOI: 10.1016/s1357-2725(99)00137-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
6-Phosphofructo-1-kinase and fructose-1,6-bisphosphatase are rate-limiting enzymes for glycolysis and gluconeogenesis respectively, in the fructose 6-phosphate/fructose 1,6-bisphosphate cycle in the liver. The effect of ribose 1,5-bisphosphate on the enzymes was investigated. Ribose 1,5-bisphosphate synergistically relieved the ATP inhibition and increased the affinity of liver 6-phosphofructo-1-kinase for fructose 6-phosphate in the presence of AMP. Ribose 1,5-bisphosphate synergistically inhibited fructose-1,6-bisphosphatase in the presence of AMP. The activating effect on 6-phosphofructo-1-kinase and the inhibitory effect on fructose-1,6-bisphosphatase suggest ribose 1,5-bisphosphate is a potent regulator of the fructose 6-phosphate/fructose 1,6-bisphosphate cycle in the liver.
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Affiliation(s)
- M Sawada
- Department of Physiology, Nihon University School of Dentistry at Matsudo, Chiba, Japan
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44
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Cárcamo JG, Yañez AJ, Ludwig HC, León O, Pinto RO, Reyes AM, Slebe JC. The C1-C2 interface residue lysine 50 of pig kidney fructose-1, 6-bisphosphatase has a crucial role in the cooperative signal transmission of the AMP inhibition. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:2242-51. [PMID: 10759847 DOI: 10.1046/j.1432-1327.2000.01227.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To understand the mechanism of signal propagation involved in the cooperative AMP inhibition of the homotetrameric enzyme pig-kidney fructose-1,6-bisphosphatase, Arg49 and Lys50 residues located at the C1-C2 interface of this enzyme were replaced using site-directed mutagenesis. The mutant enzymes Lys50Ala, Lys50Gln, Arg49Ala and Arg49Gln were expressed in Escherichia coli, purified to homogeneity and the initial rate kinetics were compared with the wild-type recombinant enzyme. The mutants exhibited kcat, Km and I50 values for fructose-2,6-bisphosphate that were similar to those of the wild-type enzyme. The kinetic mechanism of AMP inhibition with respect to Mg2+ was changed from competitive (wild-type) to noncompetitive in the mutant enzymes. The Lys50Ala and Lys50Gln mutants showed a biphasic behavior towards AMP, with total loss of cooperativity. In addition, in these mutants the mechanism of AMP inhibition with respect to fructose-1,6-bisphosphate changed from noncompetitive (wild-type) to uncompetitive. In contrast, AMP inhibition was strongly altered in Arg49Ala and Arg49Gln enzymes; the mutants had > 1000-fold lower AMP affinity relative to the wild-type enzyme and exhibited no AMP cooperativity. These studies strongly indicate that the C1-C2 interface is critical for propagation of the cooperative signal between the AMP sites on the different subunits and also in the mechanism of allosteric inhibition of the enzyme by AMP.
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Affiliation(s)
- J G Cárcamo
- Instituto de Bioquímica, Universidad Austral de Chile, Valdivia, Chile
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45
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46
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Caccuri AM, Antonini G, Ascenzi P, Nicotra M, Nuccetelli M, Mazzetti AP, Federici G, Lo Bello M, Ricci G. Temperature adaptation of glutathione S-transferase P1-1. A case for homotropic regulation of substrate binding. J Biol Chem 1999; 274:19276-80. [PMID: 10383436 DOI: 10.1074/jbc.274.27.19276] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Human glutathione S-transferase P1-1 (GST P1-1) is a homodimeric enzyme expressed in several organs as well as in the upper layers of epidermis, playing a role against carcinogenic and toxic compounds. A sophisticated mechanism of temperature adaptation has been developed by this enzyme. In fact, above 35 degrees C, glutathione (GSH) binding to GST P1-1 displays positive cooperativity, whereas negative cooperativity occurs below 25 degrees C. This binding mechanism minimizes changes of GSH affinity for GST P1-1 because of temperature fluctuation. This is a likely advantage for epithelial skin cells, which are naturally exposed to temperature variation and, incidentally, to carcinogenic compounds, always needing efficient detoxifying systems. As a whole, GST P1-1 represents the first enzyme which displays a temperature-dependent homotropic regulation of substrate (e.g. GSH) binding.
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Affiliation(s)
- A M Caccuri
- Department of Biology, University of Rome Tor Vergata, I-00133 Rome, Italy
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47
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Choe JY, Poland BW, Fromm HJ, Honzatko RB. Role of a dynamic loop in cation activation and allosteric regulation of recombinant porcine fructose-1,6-bisphosphatase. Biochemistry 1998; 37:11441-50. [PMID: 9708979 DOI: 10.1021/bi981112u] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
A disordered loop (loop 52-72, residues 52-72) in crystal structures of fructose-1,6-bisphosphatase (FBPase) has been implicated in regulatory and catalytic phenomena by studies in directed mutation. A crystal structure of FBPase in a complex with three zinc cations and the products fructose 6-phosphate (F6P) and phosphate (Pi) reveals loop 52-72 for the first time in a well-defined conformation with strong electron density. Loop 52-57 interacts primarily with the active site of its own subunit. Asp68 of the loop hydrogen bonds with Arg276 and a zinc cation located at the putative potassium activation site. Leu56 and Tyr57 of the loop pack against hydrophobic residues from two separate subunits of FBPase. A mechanism of allosteric regulation of catalysis is presented, in which AMP, by binding to its allosteric pocket, displaces loop 52-72 from the active site. Furthermore, the current structure suggests that both the alpha- and beta-anomers of F6P can be substrates in the reverse reaction catalyzed by FBPase. Mechanisms of catalysis are proposed for the reverse reaction in which Asp121 serves as a catalytic base for the alpha-anomer and Glu280 serves as a catalytic base for the beta-anomer.
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Affiliation(s)
- J Y Choe
- Department of Biochemistry and Biophysics, Iowa State University, Ames 50011, USA
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48
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Kurbanov FT, Choe JY, Honzatko RB, Fromm HJ. Directed mutations in the poorly defined region of porcine liver fructose-1,6-bisphosphatase significantly affect catalysis and the mechanism of AMP inhibition. J Biol Chem 1998; 273:17511-6. [PMID: 9651342 DOI: 10.1074/jbc.273.28.17511] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Asn64, Asp68, Lys71, Lys72, and Asp74 of porcine liver fructose-1, 6-bisphosphatase (FBPase) are conserved residues and part of a loop for which no electron density has been observed in crystal structures. Yet mutations of the above dramatically affect catalytic rates and/or AMP inhibition. The Asp74 --> Ala and Asp74 --> Asn mutant enzymes exhibited 50,000- and 2,000-fold reductions, respectively, in kcat relative to wild-type FBPase. The pH optimum for the catalytic activity of the Asp74 --> Glu, Asp68 --> Glu, Asn64 --> Gln, and Asn64 --> Ala mutant enzymes shifted from pH 7.0 (wild-type enzyme) to pH 8.5, whereas the Lys71 --> Ala mutant and Lys71,72 --> Met double mutant had optimum activity at pH 7.5. Mg2+ cooperativity, Km for fructose 1,6-bisphosphate, and Ki for fructose 2,6-bisphosphate were comparable for the mutant and wild-type enzymes. Nevertheless, for the Asp74 --> Glu, Asp68 --> Glu, Asn64 --> Gln, and Asn64 --> Ala mutants, the binding affinity for Mg2+ decreased by 40-125-fold relative to the wild-type enzyme. In addition, the Asp74 --> Glu and Asn64 --> Ala mutants exhibited no AMP cooperativity, and the kinetic mechanism of AMP inhibition with respect to Mg2+ was changed from competitive to noncompetitive. The double mutation Lys71,72 --> Met increased Ki for AMP by 175-fold and increased Mg2+ affinity by 2-fold relative to wild-type FBPase. The results reported here strongly suggest that loop 51-72 is important for catalytic activity and the mechanism of allosteric inhibition of FBPase by AMP.
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Affiliation(s)
- F T Kurbanov
- Department of Biochemistry and Biophysics, Iowa State University, Ames, Iowa 50011, USA
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49
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Shyur LF, Poland BW, Honzatko RB, Fromm HJ. Major changes in the kinetic mechanism of AMP inhibition and AMP cooperativity attend the mutation of Arg49 in fructose-1,6-bisphosphatase. J Biol Chem 1997; 272:26295-9. [PMID: 9334199 DOI: 10.1074/jbc.272.42.26295] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The significance of subunit interface residues Arg49 and Lys50 in the function of porcine liver fructose-1,6-bisphosphatase was explored by site-directed mutagenesis, initial rate kinetics, and circular dichroism spectroscopy. The Lys50 --> Met mutant had kinetic properties similar to the wild-type enzyme but was more thermostable. Mutants Arg49 --> Leu, Arg49 --> Asp, Arg49 --> Cys were less thermostable than the wild-type enzyme yet exhibited wild-type values for kcat and Km. The Ki for the competitive inhibitor fructose 2,6-bisphosphate increased 3- and 5-fold in Arg49 --> Leu and Arg49 --> Asp, respectively. The Ka for Mg2+ increased 4-8-fold for the Arg49 mutants, with no alteration in the cooperativity of Mg2+ binding. Position 49 mutants had 4-10-fold lower AMP affinity. Most significantly, the mechanism of AMP inhibition with respect to fructose 1,6-bisphosphate changed from noncompetitive (wild-type enzyme) to competitive (Arg49 --> Leu and Arg49 --> Asp mutants) and to uncompetitive (Arg49 --> Cys mutant). In addition, AMP cooperativity was absent in the Arg49 mutants. The R and T-state circular dichroism spectra of the position 49 mutants were identical and superimposable on only the R-state spectrum of the wild-type enzyme. Changes from noncompetitive to competitive inhibition by AMP can be accommodated within the framework of a steady-state Random Bi Bi mechanism. The appearance of uncompetitive inhibition, however, suggests that a more complex mechanism may be necessary to account for the kinetic properties of the enzyme.
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Affiliation(s)
- L F Shyur
- Department of Biochemistry and Biophysics, Iowa State University, Ames, Iowa 50011, USA
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50
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Shyur LF, Aleshin AE, Honzatko RB, Fromm HJ. Biochemical properties of mutant and wild-type fructose-1,6-bisphosphatases are consistent with the coupling of intra- and intersubunit conformational changes in the T- and R-state transition. J Biol Chem 1996; 271:33301-7. [PMID: 8969189 DOI: 10.1074/jbc.271.52.33301] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The significance of interactions between AMP domains in recombinant porcine fructose-1,6-bisphosphatase (FBPase) is explored by site-directed mutagenesis and kinetic characterization of homogeneous preparations of mutant enzymes. Mutations of Lys42, Ile190, and Gly191 do not perturb the circular dichroism spectra, but have significant effects on ligand binding and mechanisms of cooperativity. The Km for fructose 1,6-bisphosphate and the Ki for the competitive inhibitor, fructose 2,6-bisphosphate, decreased by as much as 4- and 8-fold, respectively, in the Q32L, K42E, K42T, I190T, and G191A mutants relative to the wild-type enzyme. Q32L, unlike the other four mutants, exhibited a 1.7-fold increase in Kcat. Mg2+ binding is sigmoidal for the five mutants as well as for the wild-type enzyme, but the Mg2+ affinities were decreased (3-22-fold) in mutant FBPases. With the exception of Q32L (8-fold increase), the 50% inhibiting concentrations of AMP for K42E, K42T, I190T, and G191A were increased over 2,000-fold (>10 mM) relative to the wild-type enzyme. Most importantly, a loss of AMP cooperativity was found with K42E, K42T, I190T, and G191A. In addition, the mechanism of AMP inhibition with respect to Mg2+ was changed from competitive to noncompetitive for K42T, I190T, and G191A FBPases. Structural modeling and kinetic studies suggest that Lys42, Ile190, and Gly191 are located at the pivot point of intersubunit conformational changes that energetically couple the Mg2+-binding site to the AMP domain of FBPase.
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Affiliation(s)
- L F Shyur
- Department of Biochemistry and Biophysics, Iowa State University, Ames, Iowa 50011, USA
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