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Benzarti M, Neises L, Oudin A, Krötz C, Viry E, Gargiulo E, Pulido C, Schmoetten M, Pozdeev V, Lorenz NI, Ronellenfitsch MW, Sumpton D, Warmoes M, Jaeger C, Lesur A, Becker B, Moussay E, Paggetti J, Niclou SP, Letellier E, Meiser J. PKM2 diverts glycolytic flux in dependence on mitochondrial one-carbon cycle. Cell Rep 2024; 43:113868. [PMID: 38421868 DOI: 10.1016/j.celrep.2024.113868] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Revised: 12/14/2023] [Accepted: 02/09/2024] [Indexed: 03/02/2024] Open
Abstract
Modeling tumor metabolism in vitro remains challenging. Here, we used galactose as an in vitro tool compound to mimic glycolytic limitation. In contrast to the established idea that high glycolytic flux reduces pyruvate kinase isozyme M2 (PKM2) activity to support anabolic processes, we have discovered that glycolytic limitation also affects PKM2 activity. Surprisingly, despite limited carbon availability and energetic stress, cells induce a near-complete block of PKM2 to divert carbons toward serine metabolism. Simultaneously, TCA cycle flux is sustained, and oxygen consumption is increased, supported by glutamine. Glutamine not only supports TCA cycle flux but also serine synthesis via distinct mechanisms that are directed through PKM2 inhibition. Finally, deleting mitochondrial one-carbon (1C) cycle reversed the PKM2 block, suggesting a potential formate-dependent crosstalk that coordinates mitochondrial 1C flux and cytosolic glycolysis to support cell survival and proliferation during nutrient-scarce conditions.
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Affiliation(s)
- Mohaned Benzarti
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg; Faculty of Science, Technology and Medicine, University of Luxembourg, Belvaux, Luxembourg; Molecular Disease Mechanisms Group, Faculty of Science, Technology and Medicine, Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Laura Neises
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Anais Oudin
- NORLUX Neuro-Oncology Laboratory, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Christina Krötz
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Elodie Viry
- Tumor Stroma Interactions, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Ernesto Gargiulo
- Tumor Stroma Interactions, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Coralie Pulido
- Animal Facility, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Maryse Schmoetten
- Molecular Disease Mechanisms Group, Faculty of Science, Technology and Medicine, Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Vitaly Pozdeev
- Molecular Disease Mechanisms Group, Faculty of Science, Technology and Medicine, Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Nadia I Lorenz
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; German Cancer Consortium, Partner Site Frankfurt/Mainz, Frankfurt am Main, Germany; Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; University Cancer Center Frankfurt (UCT), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - Michael W Ronellenfitsch
- Dr. Senckenberg Institute of Neurooncology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; German Cancer Consortium, Partner Site Frankfurt/Mainz, Frankfurt am Main, Germany; Frankfurt Cancer Institute (FCI), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; University Cancer Center Frankfurt (UCT), University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany
| | - David Sumpton
- Cancer Research U.K. Scotland Institute, Switchback Road, Bearsden, Glasgow G61 1BD, UK
| | - Marc Warmoes
- Metabolomics Platform, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Christian Jaeger
- Metabolomics Platform, Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Antoine Lesur
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Björn Becker
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Etienne Moussay
- Tumor Stroma Interactions, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Jerome Paggetti
- Tumor Stroma Interactions, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Simone P Niclou
- Faculty of Science, Technology and Medicine, University of Luxembourg, Belvaux, Luxembourg; NORLUX Neuro-Oncology Laboratory, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
| | - Elisabeth Letellier
- Molecular Disease Mechanisms Group, Faculty of Science, Technology and Medicine, Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Johannes Meiser
- Cancer Metabolism Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg.
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Swint-Kruse L, Dougherty LL, Page B, Wu T, O’Neil PT, Prasannan CB, Timmons C, Tang Q, Parente DJ, Sreenivasan S, Holyoak T, Fenton AW. PYK-SubstitutionOME: an integrated database containing allosteric coupling, ligand affinity and mutational, structural, pathological, bioinformatic and computational information about pyruvate kinase isozymes. Database (Oxford) 2023; 2023:baad030. [PMID: 37171062 PMCID: PMC10176505 DOI: 10.1093/database/baad030] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 03/29/2023] [Accepted: 04/11/2023] [Indexed: 05/13/2023]
Abstract
Interpreting changes in patient genomes, understanding how viruses evolve and engineering novel protein function all depend on accurately predicting the functional outcomes that arise from amino acid substitutions. To that end, the development of first-generation prediction algorithms was guided by historic experimental datasets. However, these datasets were heavily biased toward substitutions at positions that have not changed much throughout evolution (i.e. conserved). Although newer datasets include substitutions at positions that span a range of evolutionary conservation scores, these data are largely derived from assays that agglomerate multiple aspects of function. To facilitate predictions from the foundational chemical properties of proteins, large substitution databases with biochemical characterizations of function are needed. We report here a database derived from mutational, biochemical, bioinformatic, structural, pathological and computational studies of a highly studied protein family-pyruvate kinase (PYK). A centerpiece of this database is the biochemical characterization-including quantitative evaluation of allosteric regulation-of the changes that accompany substitutions at positions that sample the full conservation range observed in the PYK family. We have used these data to facilitate critical advances in the foundational studies of allosteric regulation and protein evolution and as rigorous benchmarks for testing protein predictions. We trust that the collected dataset will be useful for the broader scientific community in the further development of prediction algorithms. Database URL https://github.com/djparente/PYK-DB.
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Affiliation(s)
- Liskin Swint-Kruse
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Larissa L Dougherty
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Braelyn Page
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Tiffany Wu
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Pierce T O’Neil
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Charulata B Prasannan
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Cody Timmons
- Chemistry Department, Southwestern Oklahoma State University, 100 Campus Dr., Weatherford, OK 73096, USA
| | - Qingling Tang
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Daniel J Parente
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
- Department of Family Medicine and Community Health, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Shwetha Sreenivasan
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
| | - Todd Holyoak
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
- Department of Biology, University of Waterloo, 200 University Ave. W, Waterloo, ON N2L 3G1, Canada
| | - Aron W Fenton
- Department of Biochemistry and Molecular Biology, The University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160, USA
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Nandi S, Razzaghi M, Srivastava D, Dey M. Structural basis for allosteric regulation of pyruvate kinase M2 by phosphorylation and acetylation. J Biol Chem 2021; 295:17425-17440. [PMID: 33453989 DOI: 10.1074/jbc.ra120.015800] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Revised: 09/18/2020] [Indexed: 01/01/2023] Open
Abstract
Pyruvate kinase muscle isoform 2 (PKM2) is a key glycolytic enzyme and transcriptional coactivator and is critical for tumor metabolism. In cancer cells, native tetrameric PKM2 is phosphorylated or acetylated, which initiates a switch to a dimeric/monomeric form that translocates into the nucleus, causing oncogene transcription. However, it is not known how these post-translational modifications (PTMs) disrupt the oligomeric state of PKM2. We explored this question via crystallographic and biophysical analyses of PKM2 mutants containing residues that mimic phosphorylation and acetylation. We find that the PTMs elicit major structural reorganization of the fructose 1,6-bisphosphate (FBP), an allosteric activator, binding site, impacting the interaction with FBP and causing a disruption in oligomerization. To gain insight into how these modifications might cause unique outcomes in cancer cells, we examined the impact of increasing the intracellular pH (pHi) from ∼7.1 (in normal cells) to ∼7.5 (in cancer cells). Biochemical studies of WT PKM2 (wtPKM2) and the two mimetic variants demonstrated that the activity decreases as the pH is increased from 7.0 to 8.0, and wtPKM2 is optimally active and amenable to FBP-mediated allosteric regulation at pHi 7.5. However, the PTM mimetics exist as a mixture of tetramer and dimer, indicating that physiologically dimeric fraction is important and might be necessary for the modified PKM2 to translocate into the nucleus. Thus, our findings provide insight into how PTMs and pH regulate PKM2 and offer a broader understanding of its intricate allosteric regulation mechanism by phosphorylation or acetylation.
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Affiliation(s)
- Suparno Nandi
- Department of Chemistry, University of Iowa, Iowa City, Iowa, USA
| | | | | | - Mishtu Dey
- Department of Chemistry, University of Iowa, Iowa City, Iowa, USA.
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Chen H, Blum JE, Thalacker-Mercer A, Gu Z. Impact of the Whole Genome Duplication Event on PYK Activity and Effects of a PYK1 Mutation on Metabolism in S. cerevisiae. Front Mol Biosci 2021; 8:656461. [PMID: 33796550 PMCID: PMC8007964 DOI: 10.3389/fmolb.2021.656461] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 02/22/2021] [Indexed: 11/13/2022] Open
Abstract
Background: Evolution of aerobic fermentation (crabtree effect) in yeast is associated with the whole genome duplication (WGD) event, suggesting that duplication of certain genes may have altered yeast metabolism. The pyruvate kinase (PYK) gene is associated with alterations in cell metabolism, and duplicated during the WGD, generating PYK1 and PYK2. Thus, the impact of WGD on PYK activity and role of PYK in yeast metabolism were explored. Methods: PYK activity in the presence or absence of fructose-1,6-bisphosphate (FBP) was compared between pre- and post-WGD yeast. Glucose consumption, ethanol production, and oxygen consumption were measured in wildtype yeast and yeast with a T403E point mutation, which alters FBP binding affinity. Results: FBP stimulated increased PYK activity in pre-WGD yeast and in the PYK1 isoforms of post-WGD yeast, but not in the PYK2 isoforms of post-WGD yeast. Compared to wildtype, T403E mutant yeast displayed reduced glucose consumption, reduced ethanol production, and increased mitochondrial metabolism. Conclusion: The WGD event impacted the sensitivity of PYK activity to FBP. Mutations in the FBP binding domain of PYK induce metabolic shifts that favor respiration and suppress fermentation.
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Affiliation(s)
- Hong Chen
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States
| | - Jamie E Blum
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States
| | - Anna Thalacker-Mercer
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States.,Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Zhenglong Gu
- Division of Nutritional Sciences, Cornell University, Ithaca, NY, United States
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Lam SD, Babu MM, Lees J, Orengo CA. Biological impact of mutually exclusive exon switching. PLoS Comput Biol 2021; 17:e1008708. [PMID: 33651795 PMCID: PMC7954323 DOI: 10.1371/journal.pcbi.1008708] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Revised: 03/12/2021] [Accepted: 01/14/2021] [Indexed: 12/27/2022] Open
Abstract
Alternative splicing can expand the diversity of proteomes. Homologous mutually exclusive exons (MXEs) originate from the same ancestral exon and result in polypeptides with similar structural properties but altered sequence. Why would some genes switch homologous exons and what are their biological impact? Here, we analyse the extent of sequence, structural and functional variability in MXEs and report the first large scale, structure-based analysis of the biological impact of MXE events from different genomes. MXE-specific residues tend to map to single domains, are highly enriched in surface exposed residues and cluster at or near protein functional sites. Thus, MXE events are likely to maintain the protein fold, but alter specificity and selectivity of protein function. This comprehensive resource of MXE events and their annotations is available at: http://gene3d.biochem.ucl.ac.uk/mxemod/. These findings highlight how small, but significant changes at critical positions on a protein surface are exploited in evolution to alter function.
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Affiliation(s)
- Su Datt Lam
- Institute of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
- Department of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Malaysia
- * E-mail: (SDL); (JL); (CO)
| | - M. Madan Babu
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, United Kingdom
- Department of Structural Biology and Center for Data Driven Discovery, St Jude Children’s Research Hospital, Memphis, Tennessee, United States of America
| | - Jonathan Lees
- Faculty of Health and Life Sciences, Oxford Brookes University, Oxford, United Kingdom
- * E-mail: (SDL); (JL); (CO)
| | - Christine A. Orengo
- Institute of Structural and Molecular Biology, University College London, Darwin Building, Gower Street, London, United Kingdom
- * E-mail: (SDL); (JL); (CO)
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6
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Andrejc D, Možir A, Legiša M. Effect of the cancer specific shorter form of human 6-phosphofructo-1-kinase on the metabolism of the yeast Saccharomyces cerevisiae. BMC Biotechnol 2017; 17:41. [PMID: 28482870 PMCID: PMC5422889 DOI: 10.1186/s12896-017-0362-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 04/20/2017] [Indexed: 12/21/2022] Open
Abstract
Background At first glance, there appears to be a high degree of similarity between the metabolism of yeast (the Crabtree effect) and human cancer cells (the Warburg effect). At the root of both effects is accelerated metabolic flow through glycolysis which leads to overflows of ethanol and lactic acid, respectively. It has been proposed that enhanced glycolytic flow in cancer cells is triggered by the altered kinetic characteristics of the key glycolytic regulatory enzyme 6-phosphofructo-1-kinase (Pfk). Through a posttranslational modification, highly active shorter Pfk-M fragments, which are resistant to feedback inhibition, are formed after the proteolytic cleavage of the C-terminus of the native human Pfk-M. Alternatively, enhanced glycolysis is triggered by optimal growth conditions in the yeast Saccharomyces cerevisiae. Results To assess the deregulation of glycolysis in yeast cells, the sfPFKM gene encoding highly active human shorter Pfk-M fragments was introduced into pfk-null S. cerevisiae. No growth of the transformants with the sfPFKM gene was observed on glucose and fructose. Glucose even induced rapid deactivation of Pfk1 activities in such transformants. However, Pfk1 activities of the sfPFKM transformants were detected in maltose medium, but the growth in maltose was possible only after the addition of 10 mM of ethanol to the medium. Ethanol seemed to alleviate the severely unbalanced NADH/NADPH ratio in the sfPFKM cells. However, the transformants carrying modified Pfk-M enzymes grew faster than the transformants with the human native human Pfk-M enzyme in a narrow ecological niche with a low maltose concentration medium that was further improved by additional modifications. Interestingly, periodic extracellular accumulation of phenylacetaldehyde was detected during the growth of the strain with modified Pfk-M but not with the strain encoding the human native enzyme. Conclusions Highly active cancer-specific shorter Pfk-M fragments appear to trigger several controlling mechanisms in the primary metabolism of yeast S. cerevisiae cells. These results suggest more complex metabolic regulation is present in S. cerevisiae as free living unicellular eukaryotic organisms in comparison to metazoan human cells. However, increased productivity under broader growth conditions may be achieved if more gene engineering is performed to reduce or omit several controlling mechanisms. Electronic supplementary material The online version of this article (doi:10.1186/s12896-017-0362-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Darjan Andrejc
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hjadrihova 19, Si-1000, Ljubljana, Slovenia
| | - Alenka Možir
- Department of Polymer Chemistry and Technology, National Institute of Chemistry, Hajdrihova 19, Si-1000, Ljubljana, Slovenia.,Current address: Lek-Sandoz Company, Ljubljana, Slovenia
| | - Matic Legiša
- Department of Synthetic Biology and Immunology, National Institute of Chemistry, Hjadrihova 19, Si-1000, Ljubljana, Slovenia.
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7
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Israelsen WJ, Vander Heiden MG. Pyruvate kinase: Function, regulation and role in cancer. Semin Cell Dev Biol 2015; 43:43-51. [PMID: 26277545 DOI: 10.1016/j.semcdb.2015.08.004] [Citation(s) in RCA: 326] [Impact Index Per Article: 36.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Revised: 08/01/2015] [Accepted: 08/09/2015] [Indexed: 12/22/2022]
Abstract
Pyruvate kinase is an enzyme that catalyzes the conversion of phosphoenolpyruvate and ADP to pyruvate and ATP in glycolysis and plays a role in regulating cell metabolism. There are four mammalian pyruvate kinase isoforms with unique tissue expression patterns and regulatory properties. The M2 isoform of pyruvate kinase (PKM2) supports anabolic metabolism and is expressed both in cancer and normal tissue. The enzymatic activity of PKM2 is allosterically regulated by both intracellular signaling pathways and metabolites; PKM2 thus integrates signaling and metabolic inputs to modulate glucose metabolism according to the needs of the cell. Recent advances have increased our understanding of metabolic regulation by pyruvate kinase, raised new questions, and suggested the possibility of non-canonical PKM2 functions to regulate gene expression and cell cycle progression via protein-protein interactions and protein kinase activity. Here we review the structure, function, and regulation of pyruvate kinase and discuss how these properties enable regulation of PKM2 for cell proliferation and tumor growth.
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Affiliation(s)
- William J Israelsen
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA 02115, USA.
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8
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Vasu D, Sunitha MM, Srikanth L, Swarupa V, Prasad UV, Sireesha K, Yeswanth S, Kumar PS, Venkatesh K, Chaudhary A, Sarma PVGK. In Staphylococcus aureus the regulation of pyruvate kinase activity by serine/threonine protein kinase favors biofilm formation. 3 Biotech 2015; 5:505-512. [PMID: 28324552 PMCID: PMC4522715 DOI: 10.1007/s13205-014-0248-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2014] [Accepted: 08/26/2014] [Indexed: 11/30/2022] Open
Abstract
Staphylococcus aureus, a natural
inhabitant of nasopharyngeal tract, survives mainly as biofilms. Previously we have observed that S. aureus ATCC 12600 grown under anaerobic conditions exhibited high rate of biofilm formation and l-lactate dehydrogenase activity. Thus, the concentration of pyruvate plays a critical role in S. aureus, which is primarily catalyzed by pyruvate kinase (PK). Analyses of the PK gene sequence (JN645815) revealed presence of PknB site in PK gene indicating that phosphorylation may be influencing the functioning of PK. To establish this hypothesis the pure enzymes of S. aureus ATCC 12600 were obtained by expressing these genes in PK 1 and PV 1 (JN695616) clones and passing the cytosolic fractions through nickel metal chelate column. The molecular weights of pure recombinant PK and PknB are 63 and 73 kDa, respectively. The enzyme kinetics of pure PK showed KM of 0.69 ± 0.02 µM, while the KM of PknB for stpks (stpks = NLCNIPCSALLSSDITASVNCAK) substrate was 0.720 ± 0.08 mM and 0.380 ± 0.07 mM for autophosphorylation. The phosphorylated PK exhibited 40 % reduced activity (PK = 0.2 ± 0.015 μM NADH/min/ml to P-PK = 0.12 ± 0.01 μM NADH/min/ml). Elevated synthesis of pyruvate kinase was observed in S. aureus ATCC 12600 grown in anaerobic conditions suggesting that the formed pyruvate is more utilized in the synthesis phase, supporting increased rate of biofilm formation.
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Affiliation(s)
- D Vasu
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - M M Sunitha
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - L Srikanth
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - V Swarupa
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - U Venkateswara Prasad
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - K Sireesha
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - S Yeswanth
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - P Santhosh Kumar
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - K Venkatesh
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - Abhijit Chaudhary
- Department of Microbiology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India
| | - P V G K Sarma
- Department of Biotechnology, Sri Venkateswara Institute of Medical Sciences, Tirupati, AP, 517507, India.
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Systematic discovery of molecular probes targeting multiple non-orthosteric and spatially distinct sites in the botulinum neurotoxin subtype A (BoNT/A). Mol Cell Probes 2015; 29:135-43. [PMID: 25745992 DOI: 10.1016/j.mcp.2015.02.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Revised: 02/23/2015] [Accepted: 02/23/2015] [Indexed: 01/29/2023]
Abstract
The development of molecular probes targeting proteins has traditionally relied on labeling compounds already known to bind to the protein of interest. These known ligands bind to orthosteric or allosteric sites in their target protein as a way to control their activity. Binding pockets other than known orthosteric or allosteric sites may exist that are large enough to accommodate a ligand without significantly disrupting protein activity. Such sites may provide opportunities to discriminate between subtypes or other closely related proteins, since they are under less evolutionary pressure to be conserved. The Protein Scanning with Virtual Ligand Screening (PSVLS) approach was previously used to identify a novel inhibitor and a fluorescent probe against the catalytic site of the botulinum neurotoxin subtype A (BoNT/A). PSVLS screens compound databases against multiple sites within a target protein, and the results for all the sites probed against BoNT/A, not only the catalytic site, are available online. Here, we analyze the PSVLS data for multiple sites in order to identify molecular probes with affinity for binding pockets other than the catalytic site of BoNT/A. BoNT/A is a large protein with a light (LC) and a heavy (HC) chain that can be assayed separately. We used scintillation proximity assay (SPA) to test experimentally 5 probe candidates predicted computationally to have affinity for different non-orthosteric binding regions within the HC and LC, and one compound predicted not to have affinity for either domain. The binding profiles obtained experimentally confirmed the targeting of multiple and spatially distinct pockets within BoNT/A. Moreover, inhibition assay results indicate that some of these probes do not significantly interfere with the catalytic activity of BoNT/A.
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10
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Wong N, Ojo D, Yan J, Tang D. PKM2 contributes to cancer metabolism. Cancer Lett 2015; 356:184-91. [PMID: 24508027 DOI: 10.1016/j.canlet.2014.01.031] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2013] [Revised: 01/21/2014] [Accepted: 01/29/2014] [Indexed: 01/12/2023]
Abstract
Reprogramming of cell metabolism is essential for tumorigenesis, and is regulated by a complex network, in which PKM2 plays a critical role. PKM2 exists as an inactive monomer, less active dimer and active tetramer. While dimeric PKM2 diverts glucose metabolism towards anabolism through aerobic glycolysis, tetrameric PKM2 promotes the flux of glucose-derived carbons for ATP production via oxidative phosphorylation. Equilibrium of the PKM2 dimers and tetramers is critical for tumorigenesis, and is controlled by multiple factors. The PKM2 dimer also promotes aerobic glycolysis by modulating transcriptional regulation. We will discuss the current understanding of PKM2 in regulating cancer metabolism.
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Affiliation(s)
- Nicholas Wong
- Division of Nephrology, Department of Medicine, Hamilton, Ontario, Canada; Division of Urology, Department of Surgery, McMaster University, Hamilton, Ontario, Canada; Father Sean O'Sullivan Research Institute, Hamilton, Ontario, Canada; The Hamilton Center for Kidney Research, St. Joseph's Hospital, Hamilton, Ontario, Canada
| | - Diane Ojo
- Division of Nephrology, Department of Medicine, Hamilton, Ontario, Canada; Division of Urology, Department of Surgery, McMaster University, Hamilton, Ontario, Canada; Father Sean O'Sullivan Research Institute, Hamilton, Ontario, Canada; The Hamilton Center for Kidney Research, St. Joseph's Hospital, Hamilton, Ontario, Canada
| | - Judy Yan
- Division of Nephrology, Department of Medicine, Hamilton, Ontario, Canada; Division of Urology, Department of Surgery, McMaster University, Hamilton, Ontario, Canada; Father Sean O'Sullivan Research Institute, Hamilton, Ontario, Canada; The Hamilton Center for Kidney Research, St. Joseph's Hospital, Hamilton, Ontario, Canada
| | - Damu Tang
- Division of Nephrology, Department of Medicine, Hamilton, Ontario, Canada; Division of Urology, Department of Surgery, McMaster University, Hamilton, Ontario, Canada; Father Sean O'Sullivan Research Institute, Hamilton, Ontario, Canada; The Hamilton Center for Kidney Research, St. Joseph's Hospital, Hamilton, Ontario, Canada.
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11
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Lv L, Xu YP, Zhao D, Li FL, Wang W, Sasaki N, Jiang Y, Zhou X, Li TT, Guan KL, Lei QY, Xiong Y. Mitogenic and oncogenic stimulation of K433 acetylation promotes PKM2 protein kinase activity and nuclear localization. Mol Cell 2013; 52:340-52. [PMID: 24120661 PMCID: PMC4183148 DOI: 10.1016/j.molcel.2013.09.004] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2012] [Revised: 07/20/2013] [Accepted: 08/30/2013] [Indexed: 12/17/2022]
Abstract
Alternative splicing of the PKM2 gene produces two isoforms, M1 and M2, which are preferentially expressed in adult and embryonic tissues, respectively. The M2 isoform is reexpressed in human cancer and has nonmetabolic functions in the nucleus as a protein kinase. Here, we report that PKM2 is acetylated by p300 acetyltransferase at K433, which is unique to PKM2 and directly contacts its allosteric activator, fructose 1,6-bisphosphate (FBP). Acetylation prevents PKM2 activation by interfering with FBP binding and promotes the nuclear accumulation and protein kinase activity of PKM2. Acetylation-mimetic PKM2(K433) mutant promotes cell proliferation and tumorigenesis. K433 acetylation is decreased by serum starvation and cell-cell contact, increased by cell cycle stimulation, epidermal growth factor (EGF), and oncoprotein E7, and enriched in breast cancers. Hence, K433 acetylation links cell proliferation and transformation to the switch of PKM2 from a cytoplasmic metabolite kinase to a nuclear protein kinase.
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Affiliation(s)
- Lei Lv
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
- School of Life Sciences, Fudan University 200032, People’s Republic of China
| | - Yan-Ping Xu
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
- School of Life Sciences, Fudan University 200032, People’s Republic of China
| | - Di Zhao
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
| | - Fu-Long Li
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
- School of Life Sciences, Fudan University 200032, People’s Republic of China
| | - Wei Wang
- Department of Pharmacology and Moores Cancer Center, University of California at San Diego, La Jolla, CA 92093-0815, USA
| | - Naoya Sasaki
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ying Jiang
- Department of General Surgery, Zhongshan Hospital, Fudan University, Shanghai 200032, People’s Republic of China
| | - Xin Zhou
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
- School of Life Sciences, Fudan University 200032, People’s Republic of China
| | - Ting-Ting Li
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
- School of Life Sciences, Fudan University 200032, People’s Republic of China
| | - Kun-Liang Guan
- Department of Pharmacology and Moores Cancer Center, University of California at San Diego, La Jolla, CA 92093-0815, USA
| | - Qun-Ying Lei
- Key Laboratory of Molecular Medicine, Ministry of Education, and Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, People’s Republic of China
- Molecular and Cell Biology Lab, Institutes of Biomedical Sciences, Fudan University, Shanghai 200032, People’s Republic of China
| | - Yue Xiong
- School of Life Sciences, Fudan University 200032, People’s Republic of China
- Department of Biochemistry and Biophysics, Lineberger Comprehensive Cancer Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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12
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Veith N, Feldman-Salit A, Cojocaru V, Henrich S, Kummer U, Wade RC. Organism-adapted specificity of the allosteric regulation of pyruvate kinase in lactic acid bacteria. PLoS Comput Biol 2013; 9:e1003159. [PMID: 23946717 PMCID: PMC3738050 DOI: 10.1371/journal.pcbi.1003159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Accepted: 06/11/2013] [Indexed: 11/19/2022] Open
Abstract
Pyruvate kinase (PYK) is a critical allosterically regulated enzyme that links glycolysis, the primary energy metabolism, to cellular metabolism. Lactic acid bacteria rely almost exclusively on glycolysis for their energy production under anaerobic conditions, which reinforces the key role of PYK in their metabolism. These organisms are closely related, but have adapted to a huge variety of native environments. They include food-fermenting organisms, important symbionts in the human gut, and antibiotic-resistant pathogens. In contrast to the rather conserved inhibition of PYK by inorganic phosphate, the activation of PYK shows high variability in the type of activating compound between different lactic acid bacteria. System-wide comparative studies of the metabolism of lactic acid bacteria are required to understand the reasons for the diversity of these closely related microorganisms. These require knowledge of the identities of the enzyme modifiers. Here, we predict potential allosteric activators of PYKs from three lactic acid bacteria which are adapted to different native environments. We used protein structure-based molecular modeling and enzyme kinetic modeling to predict and validate potential activators of PYK. Specifically, we compared the electrostatic potential and the binding of phosphate moieties at the allosteric binding sites, and predicted potential allosteric activators by docking. We then made a kinetic model of Lactococcus lactis PYK to relate the activator predictions to the intracellular sugar-phosphate conditions in lactic acid bacteria. This strategy enabled us to predict fructose 1,6-bisphosphate as the sole activator of the Enterococcus faecalis PYK, and to predict that the PYKs from Streptococcus pyogenes and Lactobacillus plantarum show weaker specificity for their allosteric activators, while still having fructose 1,6-bisphosphate play the main activator role in vivo. These differences in the specificity of allosteric activation may reflect adaptation to different environments with different concentrations of activating compounds. The combined computational approach employed can readily be applied to other enzymes.
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Affiliation(s)
- Nadine Veith
- Molecular and Cellular Modelling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
- Department of Modelling Biological Processes, Centre for Organismal Studies (COS)/BIOQUANT, Heidelberg University, Heidelberg, Germany
| | - Anna Feldman-Salit
- Molecular and Cellular Modelling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
- Department of Modelling Biological Processes, Centre for Organismal Studies (COS)/BIOQUANT, Heidelberg University, Heidelberg, Germany
- Center for Modelling and Simulation in the Biosciences (BIOMS), Heidelberg, Germany
| | - Vlad Cojocaru
- Molecular and Cellular Modelling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
| | - Stefan Henrich
- Molecular and Cellular Modelling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
| | - Ursula Kummer
- Department of Modelling Biological Processes, Centre for Organismal Studies (COS)/BIOQUANT, Heidelberg University, Heidelberg, Germany
| | - Rebecca C. Wade
- Molecular and Cellular Modelling Group, Heidelberg Institute for Theoretical Studies (HITS), Heidelberg, Germany
- Center for Molecular Biology (ZMBH), Heidelberg University, Heidelberg, Germany
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13
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Natter K, Kohlwein SD. Yeast and cancer cells - common principles in lipid metabolism. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1831:314-26. [PMID: 22989772 PMCID: PMC3549488 DOI: 10.1016/j.bbalip.2012.09.003] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/19/2012] [Revised: 09/07/2012] [Accepted: 09/08/2012] [Indexed: 12/15/2022]
Abstract
One of the paradigms in cancer pathogenesis is the requirement of a cell to undergo transformation from respiration to aerobic glycolysis - the Warburg effect - to become malignant. The demands of a rapidly proliferating cell for carbon metabolites for the synthesis of biomass, energy and redox equivalents, are fundamentally different from the requirements of a differentiated, quiescent cell, but it remains open whether this metabolic switch is a cause or a consequence of malignant transformation. One of the major requirements is the synthesis of lipids for membrane formation to allow for cell proliferation, cell cycle progression and cytokinesis. Enzymes involved in lipid metabolism were indeed found to play a major role in cancer cell proliferation, and most of these enzymes are conserved in the yeast, Saccharomyces cerevisiae. Most notably, cancer cell physiology and metabolic fluxes are very similar to those in the fermenting and rapidly proliferating yeast. Both types of cells display highly active pathways for the synthesis of fatty acids and their incorporation into complex lipids, and imbalances in synthesis or turnover of lipids affect growth and viability of both yeast and cancer cells. Thus, understanding lipid metabolism in S. cerevisiae during cell cycle progression and cell proliferation may complement recent efforts to understand the importance and fundamental regulatory mechanisms of these pathways in cancer.
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Affiliation(s)
- Klaus Natter
- University of Graz, Institute of Molecular Biosciences, Lipidomics Research Center Graz, Humboldtstrasse 50/II, 8010 Graz,
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14
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In silico-screening approaches for lead generation: identification of novel allosteric modulators of human-erythrocyte pyruvate kinase. Methods Mol Biol 2012; 796:351-67. [PMID: 22052500 DOI: 10.1007/978-1-61779-334-9_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
Identification of allosteric binding site modulators have gained increased attention lately for their potential to be developed as selective agents with a novel chemotype and targeting perhaps a new and unique binding site with probable fewer side effects. Erythrocyte pyruvate kinase (R-PK) is an important glycolytic enzyme that can be pharmacologically modulated through its allosteric effectors for the treatment of hemolytic anemia, sickle-cell anemia, hypoxia-related diseases, and other disorders arising from erythrocyte PK malfunction. An in-silico screening approach was applied to identify novel allosteric modulators of pyruvate kinase. A small-molecules database of the National Cancer Institute (NCI), was virtually screened based on structure/ligand-based pharmacophore. The virtual screening campaign led to the identification of several compounds with similar pharmacophoric features as fructose-1,6-bisphosphate (FBP), the natural allosteric activator of the kinase. The compounds were subsequently docked into the FBP-binding site using the programs FlexX and GOLD, and their interactions with the protein were analyzed with the energy-scoring function of HINT. Seven promising candidates were obtained from the NCI and subjected to kinetics analysis, which revealed both activators and inhibitors of the R-isozyme of PK (R-PK).
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15
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The crystal structure of Toxoplasma gondii pyruvate kinase 1. PLoS One 2010; 5:e12736. [PMID: 20856875 PMCID: PMC2939071 DOI: 10.1371/journal.pone.0012736] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2010] [Accepted: 07/16/2010] [Indexed: 12/28/2022] Open
Abstract
Background Pyruvate kinase (PK), which catalyzes the final step in glycolysis converting phosphoenolpyruvate to pyruvate, is a central metabolic regulator in most organisms. Consequently PK represents an attractive therapeutic target in cancer and human pathogens, like Apicomplexans. The phylum Aplicomplexa, a group of exclusively parasitic organisms, includes the genera Plasmodium, Cryptosporidium and Toxoplasma, the etiological agents of malaria, cryptosporidiosis and toxoplasmosis respectively. Toxoplasma gondii infection causes a mild illness and is a very common infection affecting nearly one third of the world's population. Methodology/Principal Findings We have determined the crystal structure of the PK1 enzyme from T. gondii, with the B domain in the open and closed conformations. We have also characterized its enzymatic activity and confirmed glucose-6-phosphate as its allosteric activator. This is the first description of a PK enzyme in a closed inactive conformation without any bound substrate. Comparison of the two tetrameric TgPK1 structures indicates a reorientation of the monomers with a concomitant change in the buried surface among adjacent monomers. The change in the buried surface was associated with significant B domain movements in one of the interacting monomers. Conclusions We hypothesize that a loop in the interface between the A and B domains plays an important role linking the position of the B domain to the buried surface among monomers through two α-helices. The proposed model links the catalytic cycle of the enzyme with its domain movements and highlights the contribution of the interface between adjacent subunits. In addition, an unusual ordered conformation was observed in one of the allosteric binding domains and it is related to a specific apicomplexan insertion. The sequence and structural particularity would explain the atypical activation by a mono-phosphorylated sugar. The sum of peculiarities raises this enzyme as an emerging target for drug discovery. Enhanced version This article can also be viewed as an enhanced version in which the text of the article is integrated with interactive 3D representations and animated transitions. Please note that a web plugin is required to access this enhanced functionality. Instructions for the installation and use of the web plugin are available in Text S1.
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16
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Ramirez UD, Myachina F, Stith L, Jaffe EK. Docking to large allosteric binding sites on protein surfaces. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 680:481-8. [PMID: 20865533 PMCID: PMC2946403 DOI: 10.1007/978-1-4419-5913-3_54] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The inactive porphobilinogen synthase (PBGS) hexamer has an oligomer-specific and phylogenetically variable surface cavity that is not present in the active octamer. The octamer and hexamer are components of a dynamic quaternary structure equilibrium characteristic of morpheeins. Small molecules that bind to the hexamer-specific surface cavity, which is at the interface of three subunits, are predicted to act as allosteric inhibitors that function by drawing the oligomeric equilibrium toward the hexamer. We used GLIDE as a tool to enrich a 250,000 molecule library for molecules with enhanced probability of acting as hexamer-stabilizing allosteric inhibitors of PBGS from Yersinia enterocolitica. Eighty-six compounds were tested in vitro and five showed hexamer stabilization. We discuss the application of computational docking to surface cavities as an approach to find allosteric modulators of protein function with specific reference to morpheeins that function as an equilibrium of non-additive quaternary structure assemblies.
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17
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Bulik S, Grimbs S, Huthmacher C, Selbig J, Holzhütter HG. Kinetic hybrid models composed of mechanistic and simplified enzymatic rate laws--a promising method for speeding up the kinetic modelling of complex metabolic networks. FEBS J 2009; 276:410-24. [PMID: 19137631 DOI: 10.1111/j.1742-4658.2008.06784.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Kinetic modelling of complex metabolic networks - a central goal of computational systems biology - is currently hampered by the lack of reliable rate equations for the majority of the underlying biochemical reactions and membrane transporters. On the basis of biochemically substantiated evidence that metabolic control is exerted by a narrow set of key regulatory enzymes, we propose here a hybrid modelling approach in which only the central regulatory enzymes are described by detailed mechanistic rate equations, and the majority of enzymes are approximated by simplified(non mechanistic) rate equations (e.g. mass action, LinLog, Michaelis-Menten and power law) capturing only a few basic kinetic features and hence containing only a small number of parameters to be experimentally determined. To check the reliability of this approach, we have applied it to two different metabolic networks, the energy and redox metabolism of red blood cells, and the purine metabolism of hepatocytes, using in both cases available comprehensive mechanistic models as reference standards. Identification of the central regulatory enzymes was performed by employing only information on network topology and the metabolic data for a single reference state of the network [Grimbs S, Selbig J, Bulik S, Holzhutter HG & Steuer R (2007) Mol Syst Biol 3, 146, doi:10.1038/msb4100186].Calculations of stationary and temporary states under various physiological challenges demonstrate the good performance of the hybrid models. We propose the hybrid modelling approach as a means to speed up the development of reliable kinetic models for complex metabolic networks.
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Affiliation(s)
- Sascha Bulik
- Institute of Biochemistry, Charité University Medicine Berlin, Germany.
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18
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Jardón R, Gancedo C, Flores CL. The gluconeogenic enzyme fructose-1,6-bisphosphatase is dispensable for growth of the yeast Yarrowia lipolytica in gluconeogenic substrates. EUKARYOTIC CELL 2008; 7:1742-9. [PMID: 18689525 PMCID: PMC2568072 DOI: 10.1128/ec.00169-08] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 08/04/2008] [Indexed: 11/20/2022]
Abstract
The genes encoding gluconeogenic enzymes in the nonconventional yeast Yarrowia lipolytica were found to be differentially regulated. The expression of Y. lipolytica FBP1 (YlFBP1) encoding the key enzyme fructose-1,6-bisphosphatase was not repressed by glucose in contrast with the situation in other yeasts; however, this sugar markedly repressed the expression of YlPCK1, encoding phosphoenolpyruvate carboxykinase, and YlICL1, encoding isocitrate lyase. We constructed Y. lipolytica strains with two different disrupted versions of YlFBP1 and found that they grew much slower than the wild type in gluconeogenic carbon sources but that growth was not abolished as happens in most microorganisms. We attribute this growth to the existence of an alternative phosphatase with a high K(m) (2.3 mM) for fructose-1,6-bisphosphate. The gene YlFBP1 restored fructose-1,6-bisphosphatase activity and growth in gluconeogenic carbon sources to a Saccharomyces cerevisiae fbp1 mutant, but the introduction of the FBP1 gene from S. cerevisiae in the Ylfbp1 mutant did not produce fructose-1,6-bisphosphatase activity or growth complementation. Subcellular fractionation revealed the presence of fructose-1,6-bisphosphatase both in the cytoplasm and in the nucleus.
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Affiliation(s)
- Raquel Jardón
- Department of Metabolism and Cell Signaling, Instituto de Investigaciones Biomédicas Alberto Sols CSIC-UAM, Madrid, Spain
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19
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Kharalkar SS, Joshi GS, Musayev FN, Fornabaio M, Abraham DJ, Safo MK. Identification of novel allosteric regulators of human-erythrocyte pyruvate kinase. Chem Biodivers 2008; 4:2603-17. [PMID: 18027374 DOI: 10.1002/cbdv.200790213] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Erythrocyte pyruvate kinase (PK) is an important glycolytic enzyme, and manipulation of its regulatory behavior by allosteric modifiers is of interest for medicinal purposes. Human-erythrocyte PK was expressed in Rosetta cells and purified on an Ni-NTA column. A search of the small-molecules database of the National Cancer Institute (NCI), using the UNITY software, led to the identification of several compounds with similar pharmacophores as fructose-1,6-bisphosphate (FBP), the natural allosteric activator of the human kinases. The compounds were subsequently docked into the FBP binding site using the programs FlexX and GOLD, and their interactions with the protein were analyzed with the energy-scoring function of HINT. Seven promising candidates, compounds 1-7, were obtained from the NCI, and subjected to kinetics analysis, which revealed both activators and inhibitors of the R-isozyme of PK (R-PK). The allosteric effectors discovered in this study could prove to be lead compounds for developing medications for the treatment of hemolytic anemia, sickle-cell anemia, hypoxia-related diseases, and other disorders arising from erythrocyte PK malfunction.
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Affiliation(s)
- Shilpa S Kharalkar
- Department of Medicinal Chemistry, School of Pharmacy, and Institute for Structural Biology and Drug Discovery, Virginia Commonwealth University, Richmond, VA 23298, USA
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20
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Lin WY, Chang JY, Hish CH, Pan TM. Proteome response of Monascus pilosus during rice starch limitation with suppression of monascorubramine production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2007; 55:9226-9234. [PMID: 17924709 DOI: 10.1021/jf071109u] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
For centuries, red mold rice has been made by fermentation of cooked rice with Monascus species. However, the influence of different carbon sources on the metabolism of Monascus cells remains unclear. We compared the proteome response of Monascus pilosus to replacement of the rice starch fraction with lactose during cultivation, using two-dimensional gel electrophoresis, matrix-assisted laser desorption-ionization time-of-flight/time-of-flight mass spectrometry, and tandem mass spectrometry to identify the proteins expressed. The results showed that cell growth and monascorubramine pigment formation of M. pilosus were sensitive to rice starch limitation during cultivation. A total of 12 proteins were identified with statistically altered expression in the cells cultivated with lactose. These deregulated proteins were involved in glycolysis, TCA cycle, energy generation, protein folding, and peptide biosynthesis. The possible metabolic flux shifts induced by rice starch limitation were discussed. The results suggested that the suppression of monascorubramine formation could be related to the necessary energy-requiring adaptations executed in response to carbon depletion during rice starch limitation.
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Affiliation(s)
- Wun-Yuan Lin
- Department of Food Science, Nutrition and Nutraceutical Biotechnology, Shih Chien University, Taiwan, Republic of China
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21
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Spiegel PC, Kaiser SM, Simon JA, Stoddard BL. Disruption of Protein-Membrane Binding and Identification of Small-Molecule Inhibitors of Coagulation Factor VIII. ACTA ACUST UNITED AC 2004; 11:1413-22. [PMID: 15489168 DOI: 10.1016/j.chembiol.2004.08.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2004] [Revised: 08/03/2004] [Accepted: 08/04/2004] [Indexed: 11/16/2022]
Abstract
Factor VIII is a critical member of the blood coagulation cascade. It binds to the membrane surfaces of activated platelets at the site of vascular injury via a highly specific interaction between factor VIII's carboxy-terminal C2 domain and their phosphatidylserine-rich lipid bilayer. We have identified small-molecule inhibitors of factor VIII's membrane binding activity that have IC50 values as low as 2.5 microM. This interaction is approximately 10(3)-fold tighter than that of free o-phospho-L-serine. These compounds also inhibit factor VIII-dependent activation of factor X, indicating that disruption of membrane lipid binding leads to inhibition of the intrinsic coagulation pathway. The tightest binding inhibitor is specific and does not prevent membrane binding by the closely related coagulation factor V. These results indicate that this and related compounds may be used as leads to develop novel antithrombotic agents.
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Affiliation(s)
- P Clint Spiegel
- Graduate Program in Biomolecular Structure and Design, University of Washington, Seattle, Washington 98195, USA
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22
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Mazurek S, Grimm H, Boschek CB, Vaupel P, Eigenbrodt E. Pyruvate kinase type M2: a crossroad in the tumor metabolome. Br J Nutr 2002. [PMID: 11895152 DOI: 10.1079/bjn2001454] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Cell proliferation is a process that consumes large amounts of energy. A reduction in the nutrient supply can lead to cell death by ATP depletion, if cell proliferation is not limited. A key sensor for this regulation is the glycolytic enzyme pyruvate kinase, which determines whether glucose carbons are channelled to synthetic processes or used for glycolytic energy production. In unicellular organisms pyruvate kinase is regulated by ATP, ADP and AMP, by ribose 5-P, the precursor of the nucleic acid synthesis, and by the glycolytic intermediate fructose 1,6-P2 (FBP), thereby adapting cell proliferation to nutrient supply. The mammalian pyruvate kinase isoenzyme type M2 (M2-PK) displays the same kinetic properties as the pyruvate kinase enzyme from unicellular organisms. The mammalian M2-PK isoenzyme can switch between a less active dimeric form and a highly active tetrameric form which regulates the channeling of glucose carbons either to synthetic processes (dimeric form) or to glycolytic energy production (tetrameric form). Tumor cells are usually characterized by a high amount of the dimeric form leading to a strong accumulation of all glycolytic phosphometabolites above pyruvate kinase. The tetramer-dimer ratio is regulated by ATP, FBP and serine and by direct interactions with different oncoproteins (pp60v-src, HPV-16 E7). In solid tumors with sufficient oxygen supply pyruvate is supplied by glutaminolysis. Pyruvate produced in glycolysis and glutaminolysis is used for the synthesis of lactate, glutamate and fatty acids thereby releasing the hydrogen produced in the glycolytic glyceraldehyde 3-phosphate dehydrogenase reaction.
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Affiliation(s)
- S Mazurek
- Institute for Biochemistry & Endocrinology, Veterinary Faculty, University of Giessen, Germany
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23
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Fenton AW, Blair JB. Kinetic and allosteric consequences of mutations in the subunit and domain interfaces and the allosteric site of yeast pyruvate kinase. Arch Biochem Biophys 2002; 397:28-39. [PMID: 11747307 DOI: 10.1006/abbi.2001.2634] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mechanism by which pyruvate kinase (PK) is allosterically activated by fructose-1,6-bisphosphate (FBP) is poorly understood. To identify residues key to allostery of yeast PK, a point mutation strategy was used. T403E and R459Q mutations in the FBP binding site caused reduced FBP affinity. Introducing positive charges at the 403, 458, and 406 positions in the FBP binding site had little consequence. The mutation Q299N in the A [bond] A subunit interface caused the enzyme response to ADP to be sensitive to FBP. The T311M A [bond] A interface mutant has a decreased affinity for PEP and FBP, and is dependent on FBP for activity. The R369A mutation in the C [bond] C interface only moderately influenced allostery. Creating an E392A mutation in the C [bond] C subunit interface eliminated all cooperativity and allosteric regulation. None of the seven A [bond] C domain interface mutations altered allostery. A model that includes a central role for E392 in allosteric regulation of yeast PK is proposed.
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Affiliation(s)
- Aron W Fenton
- Department of Biochemistry and Molecular Biology, Oklahoma State University, Stillwater, Oklahoma 74078, USA.
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24
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Current awareness on yeast. Yeast 2001; 18:577-84. [PMID: 11284013 DOI: 10.1002/yea.684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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25
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Metzler DE, Metzler CM, Sauke DJ. The Organization of Metabolism. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50020-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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