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Ayoub N, Gedeon A, Munier-Lehmann H. A journey into the regulatory secrets of the de novo purine nucleotide biosynthesis. Front Pharmacol 2024; 15:1329011. [PMID: 38444943 PMCID: PMC10912719 DOI: 10.3389/fphar.2024.1329011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Accepted: 02/01/2024] [Indexed: 03/07/2024] Open
Abstract
De novo purine nucleotide biosynthesis (DNPNB) consists of sequential reactions that are majorly conserved in living organisms. Several regulation events take place to maintain physiological concentrations of adenylate and guanylate nucleotides in cells and to fine-tune the production of purine nucleotides in response to changing cellular demands. Recent years have seen a renewed interest in the DNPNB enzymes, with some being highlighted as promising targets for therapeutic molecules. Herein, a review of two newly revealed modes of regulation of the DNPNB pathway has been carried out: i) the unprecedent allosteric regulation of one of the limiting enzymes of the pathway named inosine 5'-monophosphate dehydrogenase (IMPDH), and ii) the supramolecular assembly of DNPNB enzymes. Moreover, recent advances that revealed the therapeutic potential of DNPNB enzymes in bacteria could open the road for the pharmacological development of novel antibiotics.
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Affiliation(s)
- Nour Ayoub
- Institut Pasteur, Université Paris Cité, INSERM UMRS-1124, Paris, France
| | - Antoine Gedeon
- Sorbonne Université, École Normale Supérieure, Université PSL, CNRS UMR7203, Laboratoire des Biomolécules, LBM, Paris, France
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2
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Xu M, Neelands T, Powers AS, Liu Y, Miller SD, Pintilie GD, Bois JD, Dror RO, Chiu W, Maduke M. CryoEM structures of the human CLC-2 voltage-gated chloride channel reveal a ball-and-chain gating mechanism. eLife 2024; 12:RP90648. [PMID: 38345841 PMCID: PMC10942593 DOI: 10.7554/elife.90648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024] Open
Abstract
CLC-2 is a voltage-gated chloride channel that contributes to electrical excitability and ion homeostasis in many different tissues. Among the nine mammalian CLC homologs, CLC-2 is uniquely activated by hyperpolarization, rather than depolarization, of the plasma membrane. The molecular basis for the divergence in polarity of voltage gating among closely related homologs has been a long-standing mystery, in part because few CLC channel structures are available. Here, we report cryoEM structures of human CLC-2 at 2.46 - 2.76 Å, in the presence and absence of the selective inhibitor AK-42. AK-42 binds within the extracellular entryway of the Cl--permeation pathway, occupying a pocket previously proposed through computational docking studies. In the apo structure, we observed two distinct conformations involving rotation of one of the cytoplasmic C-terminal domains (CTDs). In the absence of CTD rotation, an intracellular N-terminal 15-residue hairpin peptide nestles against the TM domain to physically occlude the Cl--permeation pathway. This peptide is highly conserved among species variants of CLC-2 but is not present in other CLC homologs. Previous studies suggested that the N-terminal domain of CLC-2 influences channel properties via a "ball-and-chain" gating mechanism, but conflicting data cast doubt on such a mechanism, and thus the structure of the N-terminal domain and its interaction with the channel has been uncertain. Through electrophysiological studies of an N-terminal deletion mutant lacking the 15-residue hairpin peptide, we support a model in which the N-terminal hairpin of CLC-2 stabilizes a closed state of the channel by blocking the cytoplasmic Cl--permeation pathway.
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Affiliation(s)
- Mengyuan Xu
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Torben Neelands
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
| | - Alexander S Powers
- Department of Chemistry, Stanford UniversityStanfordUnited States
- Department of Computer Science, Stanford UniversityStanfordUnited States
- Department of Structural Biology, Stanford UniversityStanfordUnited States
- Institute for Computational and Mathematical Engineering, Stanford UniversityStanfordUnited States
| | - Yan Liu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford UniversityStanfordUnited States
| | - Steven D Miller
- Department of Chemistry, Stanford UniversityStanfordUnited States
| | - Grigore D Pintilie
- Department of Bioengineering and Department of Microbiology and Immunology, Stanford UniversityStanfordUnited States
| | - J Du Bois
- Department of Chemistry, Stanford UniversityStanfordUnited States
| | - Ron O Dror
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
- Department of Computer Science, Stanford UniversityStanfordUnited States
- Department of Structural Biology, Stanford UniversityStanfordUnited States
- Institute for Computational and Mathematical Engineering, Stanford UniversityStanfordUnited States
| | - Wah Chiu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford UniversityStanfordUnited States
- Department of Bioengineering and Department of Microbiology and Immunology, Stanford UniversityStanfordUnited States
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford UniversityStanfordUnited States
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3
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Xu M, Neelands T, Powers AS, Liu Y, Miller SD, Pintilie G, Bois JD, Dror RO, Chiu W, Maduke M. CryoEM structures of the human CLC-2 voltage gated chloride channel reveal a ball and chain gating mechanism. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.13.553136. [PMID: 37645939 PMCID: PMC10462068 DOI: 10.1101/2023.08.13.553136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
CLC-2 is a voltage-gated chloride channel that contributes to electrical excitability and ion homeostasis in many different mammalian tissues and cell types. Among the nine mammalian CLC homologs, CLC-2 is uniquely activated by hyperpolarization, rather than depolarization, of the plasma membrane. The molecular basis for the divergence in polarity of voltage gating mechanisms among closely related CLC homologs has been a long-standing mystery, in part because few CLC channel structures are available, and those that exist exhibit high conformational similarity. Here, we report cryoEM structures of human CLC-2 at 2.46 - 2.76 Å, in the presence and absence of the potent and selective inhibitor AK-42. AK-42 binds within the extracellular entryway of the Cl--permeation pathway, occupying a pocket previously proposed through computational docking studies. In the apo structure, we observed two distinct apo conformations of CLC-2 involving rotation of one of the cytoplasmic C-terminal domains (CTDs). In the absence of CTD rotation, an intracellular N-terminal 15-residue hairpin peptide nestles against the TM domain to physically occlude the Cl--permeation pathway from the intracellular side. This peptide is highly conserved among species variants of CLC-2 but is not present in any other CLC homologs. Previous studies suggested that the N-terminal domain of CLC-2 influences channel properties via a "ball-and-chain" gating mechanism, but conflicting data cast doubt on such a mechanism, and thus the structure of the N-terminal domain and its interaction with the channel has been uncertain. Through electrophysiological studies of an N-terminal deletion mutant lacking the 15-residue hairpin peptide, we show that loss of this short sequence increases the magnitude and decreases the rectification of CLC-2 currents expressed in mammalian cells. Furthermore, we show that with repetitive hyperpolarization WT CLC-2 currents increase in resemblance to the hairpin-deleted CLC-2 currents. These functional results combined with our structural data support a model in which the N-terminal hairpin of CLC-2 stabilizes a closed state of the channel by blocking the cytoplasmic Cl--permeation pathway.
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Affiliation(s)
- Mengyuan Xu
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
| | - Torben Neelands
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
| | - Alexander S. Powers
- Department of Chemistry, Stanford University, Stanford, CA 94305
- Department of Computer Science, Stanford University, Stanford, CA 94305
- Department of Structural Biology, Stanford University, Stanford, CA 94305
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305
| | - Yan Liu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park 94025
| | - Steven D. Miller
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Grigore Pintilie
- Department of Bioengineering and Department of Microbiology and Immunology, Stanford University, Stanford, 94305
| | - J. Du Bois
- Department of Chemistry, Stanford University, Stanford, CA 94305
| | - Ron O. Dror
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
- Department of Computer Science, Stanford University, Stanford, CA 94305
- Department of Structural Biology, Stanford University, Stanford, CA 94305
- Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305
| | - Wah Chiu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park 94025
- Department of Bioengineering and Department of Microbiology and Immunology, Stanford University, Stanford, 94305
| | - Merritt Maduke
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305
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Conter C, Favretto F, Dominici P, Martinez-Cruz LA, Astegno A. Key substrate recognition residues in the active site of cystathionine beta-synthase from Toxoplasma gondii. Proteins 2023; 91:1383-1393. [PMID: 37163386 DOI: 10.1002/prot.26507] [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: 02/08/2023] [Revised: 03/28/2023] [Accepted: 04/19/2023] [Indexed: 05/12/2023]
Abstract
Cystathionine β-synthase (CBS) catalyzes the condensation of l-serine and l-homocysteine to give l-cystathionine in the transsulfuration pathway. Recently, a few O-acetylserine (l-OAS)-dependent CBSs (OCBSs) have been found in bacteria that can exclusively function with l-OAS. CBS from Toxoplasma gondii (TgCBS) can efficiently use both l-serine and l-OAS to form l-cystathionine. In this work, a series of site-specific variants substituting S84, Y160, and Y246 with hydrophobic residues found at the same positions in OCBSs was generated to explore the roles of the hydroxyl moieties of these residues as determinants of l-serine/l-OAS preference in TgCBS. We found that the S84A/Y160F/Y246V triple mutant behaved like an OCBS in terms of both substrate requirements, showing β-replacement activity only with l-OAS, and pH optimum, which is decreased by ~1 pH unit. Formation of a stable aminoacrylate upon reaction with l-serine is prevented by the triple mutation, indicating the importance of the H-bonds between the hydroxyl groups of Y160, Y246, and S84 with l-serine in formation of the intermediate. Analysis of the independent effect of each mutation on TgCBS activity and investigation of the protein-aminoacrylate complex structure allowed for the conclusion that the hydroxyl group of Y246 has a major, but not exclusive, role in controlling the l-serine preference by efficiently stabilizing its leaving group. These studies demonstrate that differences in substrate specificity of CBSs are controlled by natural variations in as few as three residue positions. A better understanding of substrate specificity in TgCBS will facilitate the design of new antimicrobial compounds.
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Affiliation(s)
- Carolina Conter
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Filippo Favretto
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Paola Dominici
- Department of Biotechnology, University of Verona, Verona, Italy
| | - Luis Alfonso Martinez-Cruz
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Derio, Spain
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5
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Gedeon A, Ayoub N, Brûlé S, Raynal B, Karimova G, Gelin M, Mechaly A, Haouz A, Labesse G, Munier‐Lehmann H. Insight into the role of the Bateman domain at the molecular and physiological levels through engineered IMP dehydrogenases. Protein Sci 2023; 32:e4703. [PMID: 37338125 PMCID: PMC10357500 DOI: 10.1002/pro.4703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/15/2023] [Accepted: 06/06/2023] [Indexed: 06/21/2023]
Abstract
Inosine 5'-monophosphate (IMP) dehydrogenase (IMPDH) is an ubiquitous enzyme that catalyzes the NAD+ -dependent oxidation of inosine 5'-monophosphate into xanthosine 5'-monophosphate. This enzyme is formed of two distinct domains, a core domain where the catalytic reaction occurs, and a less-conserved Bateman domain. Our previous studies gave rise to the classification of bacterial IMPDHs into two classes, according to their oligomeric and kinetic properties. MgATP is a common effector but cause to different effects when it binds within the Bateman domain: it is either an allosteric activator for Class I IMPDHs or a modulator of the oligomeric state for Class II IMPDHs. To get insight into the role of the Bateman domain in the dissimilar properties of the two classes, deleted variants of the Bateman domain and chimeras issued from the interchange of the Bateman domain between the three selected IMPDHs have been generated and characterized using an integrative structural biology approach. Biochemical, biophysical, structural, and physiological studies of these variants unveil the Bateman domain as being the carrier of the molecular behaviors of both classes.
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Affiliation(s)
- Antoine Gedeon
- Institut Pasteur, Université Paris Cité, Unité de Chimie et Biocatalyse, CNRS UMR3523ParisFrance
- Present address:
Institut Pasteur, Université Paris Cité, Unité de Microbiologie Structurale, CNRS UMR3525ParisFrance
| | - Nour Ayoub
- Institut Pasteur, Université Paris Cité, Unité de Chimie et Biocatalyse, CNRS UMR3523ParisFrance
- Present address:
Institut Pasteur, Université Paris Cité, Plate‐Forme de Criblage Chémogénomique et Biologique, CNRS UMR3523ParisFrance
| | - Sébastien Brûlé
- Institut Pasteur, Université Paris Cité, Plate‐Forme de Biophysique Moléculaire, C2RT, CNRS UMR3528ParisFrance
| | - Bertrand Raynal
- Institut Pasteur, Université Paris Cité, Plate‐Forme de Biophysique Moléculaire, C2RT, CNRS UMR3528ParisFrance
| | - Gouzel Karimova
- Institut Pasteur, Université Paris Cité, Unité de Biochimie des Interactions Macromoléculaires, CNRS UMR3528ParisFrance
| | - Muriel Gelin
- Centre de Biologie StructuraleUniversité Montpellier, INSERM, CNRSMontpellierFrance
| | - Ariel Mechaly
- Institut Pasteur, Université Paris Cité, Plate‐Forme de Cristallographie, C2RT, CNRS UMR3528ParisFrance
| | - Ahmed Haouz
- Institut Pasteur, Université Paris Cité, Plate‐Forme de Cristallographie, C2RT, CNRS UMR3528ParisFrance
| | - Gilles Labesse
- Centre de Biologie StructuraleUniversité Montpellier, INSERM, CNRSMontpellierFrance
| | - Hélène Munier‐Lehmann
- Institut Pasteur, Université Paris Cité, Unité de Chimie et Biocatalyse, CNRS UMR3523ParisFrance
- Present address:
Institut Pasteur, Université Paris Cité, Plate‐Forme de Criblage Chémogénomique et Biologique, CNRS UMR3523ParisFrance
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6
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Yazdani M, Zamani J, Fatemi SSA. Identification of a potent dual-function inhibitor for hIMPDH isoforms by computer-aided drug discovery approaches. Front Pharmacol 2022; 13:977568. [PMID: 36386211 PMCID: PMC9643795 DOI: 10.3389/fphar.2022.977568] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 09/29/2022] [Indexed: 11/19/2023] Open
Abstract
Inosine monophosphate dehydrogenase (IMPDH) is a key enzyme in de novo biosynthesis of purine nucleotides. Due to this important role, it is a great target to drug discovery for a wide range of activities, especially immunosuppressant in heart and kidney transplantation. Both human IMPDH isoforms are expressed in stimulated lymphocytes. In addition to the side effects of existing drugs, previous studies have mainly focused on the type II isoform. In this study, virtual screening and computer-aided approaches were employed to identify potential drugs with simultaneous inhibitory effects on both human IMPDH isoforms. After Re-docking, Double-step docking, and identification of virtual hits based on the PLANTS scoring function, drug-likeness and ADME-Tox assessments of the topmost ligands were performed. Following further evaluation, the best ligand was selected and, in complex with both isoforms, simulated in monomeric and tetrameric forms using molecular dynamics to evaluate its stability and binding pattern. The results showed a potential drug candidate [(S)-N-(3-hydroxy-1-(4-hydroxyphenyl) propyl)-2-(3-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl) acetamide] with a high inhibitory effect on the two human IMPDH isoforms. This drug-like inhibitor could potentially serve as an immunosuppressant to prevent transplant rejection response by inhibiting B- and T-lymphocyte proliferation. In addition, its effect can be evaluated in various therapeutic targets in which IMPDH is known as a therapeutic target, especially in Covid-19 patients.
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Affiliation(s)
- Meysam Yazdani
- Department of Systems Biotechnology, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Javad Zamani
- Department of Plant Molecular Biotechnology, Institute of Agricultural Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Seyed Safa-Ali Fatemi
- Department of Systems Biotechnology, Institute of Industrial and Environmental Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
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7
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Giammarinaro PI, Young MKM, Steinchen W, Mais CN, Hochberg G, Yang J, Stevenson DM, Amador-Noguez D, Paulus A, Wang JD, Bange G. Diadenosine tetraphosphate regulates biosynthesis of GTP in Bacillus subtilis. Nat Microbiol 2022; 7:1442-1452. [PMID: 35953658 PMCID: PMC10439310 DOI: 10.1038/s41564-022-01193-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 06/29/2022] [Indexed: 11/09/2022]
Abstract
Diadenosine tetraphosphate (Ap4A) is a putative second messenger molecule that is conserved from bacteria to humans. Nevertheless, its physiological role and the underlying molecular mechanisms are poorly characterized. We investigated the molecular mechanism by which Ap4A regulates inosine-5'-monophosphate dehydrogenase (IMPDH, a key branching point enzyme for the biosynthesis of adenosine or guanosine nucleotides) in Bacillus subtilis. We solved the crystal structure of BsIMPDH bound to Ap4A at a resolution of 2.45 Å to show that Ap4A binds to the interface between two IMPDH subunits, acting as the glue that switches active IMPDH tetramers into less active octamers. Guided by these insights, we engineered mutant strains of B. subtilis that bypass Ap4A-dependent IMPDH regulation without perturbing intracellular Ap4A pools themselves. We used metabolomics, which suggests that these mutants have a dysregulated purine, and in particular GTP, metabolome and phenotypic analysis, which shows increased sensitivity of B. subtilis IMPDH mutant strains to heat compared with wild-type strains. Our study identifies a central role for IMPDH in remodelling metabolism and heat resistance, and provides evidence that Ap4A can function as an alarmone.
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Affiliation(s)
- Pietro I Giammarinaro
- Department of Chemistry and Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany
| | - Megan K M Young
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - Wieland Steinchen
- Department of Chemistry and Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany
| | - Christopher-Nils Mais
- Department of Chemistry and Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany
| | - Georg Hochberg
- Department of Chemistry and Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany
| | - Jin Yang
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | - David M Stevenson
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA
| | | | - Anja Paulus
- Department of Chemistry and Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany
| | - Jue D Wang
- Department of Bacteriology, University of Wisconsin-Madison, Madison, WI, USA.
| | - Gert Bange
- Department of Chemistry and Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany.
- Max Planck Institute for Terrestrial Microbiology, Marburg, Germany.
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8
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Zhou JR, Li J, Lin JX, Xu HM, Chu N, Wang QN, Gao SJ. Genome-wide characterization of cys-tathionine-β-synthase domain-containing proteins in sugarcane reveals their role in defense responses under multiple stressors. FRONTIERS IN PLANT SCIENCE 2022; 13:985653. [PMID: 36092401 PMCID: PMC9453547 DOI: 10.3389/fpls.2022.985653] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/02/2022] [Indexed: 06/15/2023]
Abstract
Cys-tathionine-β-synthase (CBS) domain-containing proteins (CDCPs) are essential for regulating plant responses to various biotic and abiotic stressors. This study describes the systematic identification and characterization of CDCP family genes in Saccharum spontaneum. A total of 95 SsCDCP genes and eight phylogenetic groups were identified that were distributed over 29 chromosomes of the AP85-441 genome. Most (78/95) SsCDCPs underwent fragment duplication events, and 64 gene pairs were located in synteny blocks. Expression profiling of nine ShCDCPs was also carried out in the Saccharum spp. cultivars ROC22 and MT11-611 that are resistant and susceptible to red stripe, respectively, in response to: (i) Infection by the bacterial pathogen Acidovorax avenue subsp. avenae (Aaa); (ii) abiotic stressors (drought and salinity); and (iii) exogenous salicylic acid (SA) treatment. Members of one gene pair (ShCBSD-PB1-5A and ShCBSD-PB1-7A-1) with a fragment duplication event acted as negative regulators in sugarcane under four stresses, as supported by the significantly decreased expression levels of ShCBSD-PB1-5A (23-83%) and ShCBSD-PB1-7A-1 (15-75%) at all-time points, suggesting that they have functional redundancy. Genes in another pair, ShCBS-4C and ShCBS-4D-1, which have a fragment duplication event, play opposing regulatory roles in sugarcane exposed to multiple stresses, particularly Aaa and NaCl treatments. ShCBS-4C expression was significantly decreased by 32-77%, but ShCBS-4D-1 expression was dramatically upregulated by 1.2-6.2-fold in response to Aaa treatment of both cultivars across all-time points. This result suggested that both genes exhibited functional divergence. Meanwhile, the expression of SsCBSDCBS-5A was significantly upregulated in ROC22 by 1.4-4.6-fold in response to the four stressors. These findings provide important clues for further elucidating the function of ShCDCP genes in sugarcane responding to a diverse range of stresses.
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Affiliation(s)
- Jing-Ru Zhou
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Juan Li
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Jia-Xin Lin
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Hui-Mei Xu
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Na Chu
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
| | - Qin-Nan Wang
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
- Institute of Nanfan and Seed Industry, Guangdong Academy of Sciences, Guangzhou, China
| | - San-Ji Gao
- National Engineering Research Center for Sugarcane, Fujian Agriculture and Forestry University, Fuzhou, China
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9
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Insights into Domain Organization and Regulatory Mechanism of Cystathionine Beta-Synthase from Toxoplasma gondii. Int J Mol Sci 2022; 23:ijms23158169. [PMID: 35897745 PMCID: PMC9331509 DOI: 10.3390/ijms23158169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Revised: 07/20/2022] [Accepted: 07/20/2022] [Indexed: 11/25/2022] Open
Abstract
Cystathionine beta-synthase (CBS) is a key regulator of homocysteine metabolism. Although eukaryotic CBS have a similar domain architecture with a catalytic core and a C-terminal Bateman module, their regulation varies widely across phyla. In human CBS (HsCBS), the C-terminus has an autoinhibitory effect by acting as a cap that avoids the entry of substrates into the catalytic site. The binding of the allosteric modulator AdoMet to this region alleviates this cap, allowing the protein to progress from a basal toward an activated state. The same activation is obtained by artificial removal or heat-denaturation of the Bateman module. Recently, we reported the crystal structure of CBS from Toxoplasma gondii (TgCBS) showing that the enzyme assembles into basket-like dimers similar to the basal conformers of HsCBS. These findings would suggest a similar lid function for the Bateman module which, as in HsCBS, should relax in the absence of the C-terminal module. However, herein we demonstrate that, in contrast with HsCBS, removal of the Bateman module in TgCBS through deletion mutagenesis, limited proteolysis, or thermal denaturation has no effects on its activity, oligomerization, and thermal stability. This opposite behavior we have now found in TgCBS provides evidence of a novel type of CBS regulation.
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10
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Heidemann JL, Neumann P, Krüger L, Wicke D, Vinhoven L, Linden A, Dickmanns A, Stülke J, Urlaub H, Ficner R. Structural basis for c-di-AMP-dependent regulation of the bacterial stringent response by receptor protein DarB. J Biol Chem 2022; 298:102144. [PMID: 35714772 PMCID: PMC9293649 DOI: 10.1016/j.jbc.2022.102144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Revised: 06/09/2022] [Accepted: 06/11/2022] [Indexed: 10/31/2022] Open
Abstract
The bacterial second messenger c-di-AMP controls essential cellular processes, including potassium and osmolyte homeostasis. This makes synthesizing enzymes and components involved in c-di-AMP signal transduction intriguing as potential targets for drug development. The c-di-AMP receptor protein DarB of Bacillus subtilis is known to bind the Rel protein and trigger the Rel-dependent stringent response to stress conditions; however, the structural basis for this trigger is unclear. Here we report crystal structures of DarB in the ligand-free state and of DarB complexed with c-di-AMP, 3´3´-cGAMP, and AMP. We show that DarB forms a homodimer with a parallel, head-to-head assembly of the monomers. We also confirm the DarB dimer binds two cyclic di-nucleotide molecules or two AMP molecules; only one adenine of bound c-di-AMP is specifically recognized by DarB, while the second protrudes out of the donut-shaped protein. This enables DarB to bind also 3´3´-cGAMP, as only the adenine fits in the active site. In absence of c-di-AMP, we show DarB binds to Rel and stimulates (p)ppGpp synthesis, whereas the presence of c-di-AMP abolishes this interaction. Furthermore, the DarB crystal structures reveal no conformational changes upon c-di-AMP binding, leading us to conclude the regulatory function of DarB on Rel must be controlled directly by the bound c-di-AMP. We thus derived a structural model of the DarB-Rel complex via in silico docking, which was validated with mass spectrometric analysis of the chemically cross-linked DarB-Rel complex and mutagenesis studies. We suggest, based on the predicted complex structure, a mechanism of stringent response regulation by c-di-AMP.
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Affiliation(s)
| | | | - Larissa Krüger
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Dennis Wicke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | | | - Andreas Linden
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
| | | | - Jörg Stülke
- Department of General Microbiology, Institute for Microbiology & Genetics, GZMB, Georg-August-University Göttingen, 37077 Göttingen, Germany
| | - Henning Urlaub
- Bioanalytical Mass Spectrometry, Max Planck Institute for Biophysical Chemistry, 37077 Göttingen, Germany
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11
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Seebacher F, Beaman J. Evolution of plasticity: metabolic compensation for fluctuating energy demands at the origin of life. J Exp Biol 2022; 225:274636. [PMID: 35254445 DOI: 10.1242/jeb.243214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phenotypic plasticity of physiological functions enables rapid responses to changing environments and may thereby increase the resilience of organisms to environmental change. Here, we argue that the principal hallmarks of life itself, self-replication and maintenance, are contingent on the plasticity of metabolic processes ('metabolic plasticity'). It is likely that the Last Universal Common Ancestor (LUCA), 4 billion years ago, already possessed energy-sensing molecules that could adjust energy (ATP) production to meet demand. The earliest manifestation of metabolic plasticity, switching cells from growth and storage (anabolism) to breakdown and ATP production (catabolism), coincides with the advent of Darwinian evolution. Darwinian evolution depends on reliable translation of information from information-carrying molecules, and on cell genealogy where information is accurately passed between cell generations. Both of these processes create fluctuating energy demands that necessitate metabolic plasticity to facilitate replication of genetic material and (proto)cell division. We propose that LUCA possessed rudimentary forms of these capabilities. Since LUCA, metabolic networks have increased in complexity. Generalist founder enzymes formed the basis of many derived networks, and complexity arose partly by recruiting novel pathways from the untapped pool of reactions that are present in cells but do not have current physiological functions (the so-called 'underground metabolism'). Complexity may thereby be specific to environmental contexts and phylogenetic lineages. We suggest that a Boolean network analysis could be useful to model the transition of metabolic networks over evolutionary time. Network analyses can be effective in modelling phenotypic plasticity in metabolic functions for different phylogenetic groups because they incorporate actual biochemical regulators that can be updated as new empirical insights are gained.
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Affiliation(s)
- Frank Seebacher
- School of Life and Environmental Sciences, A08, University of Sydney, Sydney, NSW 2006, Australia
| | - Julian Beaman
- College of Science and Engineering, Flinders University, Bedford Park, SA 5042, Australia
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12
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Hu Z, Li M, Cao Y, Akan OD, Guo T, Luo F. Targeting AMPK Signaling by Dietary Polyphenols in Cancer Prevention. Mol Nutr Food Res 2021; 66:e2100732. [PMID: 34802178 DOI: 10.1002/mnfr.202100732] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 11/03/2021] [Indexed: 12/14/2022]
Abstract
Cancer is a serious public health problem in the world and a major disease affecting human health. Dietary polyphenols have shown good potential in the treatment of various cancers. It is worth noting that cancer cells usually exhibit metabolic abnormalities of high glucose intake and inefficient utilization. AMPK is the key molecule in the regulation of energy metabolism and is closely related with obesity and diabetes. Recent studies indicate that AMPK also plays an important role in cancer prevention and regulating cancer-related genes and pathways, and dietary polyphenols can significantly regulate AMPK activity. In this review, the progress of dietary polyphenols preventing carcinogenesis via AMPK pathway is systemically summarized. From the viewpoint of interfering energy metabolism, the anti-cancer effects of dietary polyphenols are explained. AMPK pathway modulated by different dietary polyphenols affects pathways and target genes are summarized. Dietary polyphenols exert anti-cancer effect through the target molecules regulated by AMPK, which broadens the understanding of polyphenols anti-cancer mechanisms and provides value reference for the investigators of the novel field.
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Affiliation(s)
- Zuomin Hu
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Mengyuan Li
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Yunyun Cao
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Otobong Donald Akan
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Tianyi Guo
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
| | - Feijun Luo
- Hunan Key Laboratory of Processed Food for Special Medical Purpose, Hunan Key Laboratory of Deeply Processing and Quality Control of Cereals and Oils, Hunan Key Laboratory of Forestry Edible Resources Safety and Processing, Central South University of Forestry and Technology, Changsha, Hunan, 410004, China
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13
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Ferguson F, McLennan AG, Urbaniak MD, Jones NJ, Copeland NA. Re-evaluation of Diadenosine Tetraphosphate (Ap 4A) From a Stress Metabolite to Bona Fide Secondary Messenger. Front Mol Biosci 2020; 7:606807. [PMID: 33282915 PMCID: PMC7705103 DOI: 10.3389/fmolb.2020.606807] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 10/19/2020] [Indexed: 01/14/2023] Open
Abstract
Cellular homeostasis requires adaption to environmental stress. In response to various environmental and genotoxic stresses, all cells produce dinucleoside polyphosphates (NpnNs), the best studied of which is diadenosine tetraphosphate (Ap4A). Despite intensive investigation, the precise biological roles of these molecules have remained elusive. However, recent studies have elucidated distinct and specific signaling mechanisms for these nucleotides in prokaryotes and eukaryotes. This review summarizes these key discoveries and describes the mechanisms of Ap4A and Ap4N synthesis, the mediators of the cellular responses to increased intracellular levels of these molecules and the hydrolytic mechanisms required to maintain low levels in the absence of stress. The intracellular responses to dinucleotide accumulation are evaluated in the context of the "friend" and "foe" scenarios. The "friend (or alarmone) hypothesis" suggests that ApnN act as bona fide secondary messengers mediating responses to stress. In contrast, the "foe" hypothesis proposes that ApnN and other NpnN are produced by non-canonical enzymatic synthesis as a result of physiological and environmental stress in critically damaged cells but do not actively regulate mitigating signaling pathways. In addition, we will discuss potential target proteins, and critically assess new evidence supporting roles for ApnN in the regulation of gene expression, immune responses, DNA replication and DNA repair. The recent advances in the field have generated great interest as they have for the first time revealed some of the molecular mechanisms that mediate cellular responses to ApnN. Finally, areas for future research are discussed with possible but unproven roles for intracellular ApnN to encourage further research into the signaling networks that are regulated by these nucleotides.
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Affiliation(s)
- Freya Ferguson
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Materials Science Institute, Lancaster University, Lancaster, United Kingdom
| | - Alexander G McLennan
- Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Michael D Urbaniak
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom
| | - Nigel J Jones
- Department of Molecular Physiology and Cell Signalling, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, United Kingdom
| | - Nikki A Copeland
- Biomedical and Life Sciences, Faculty of Health and Medicine, Lancaster University, Lancaster, United Kingdom.,Materials Science Institute, Lancaster University, Lancaster, United Kingdom
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14
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Conter C, Fruncillo S, Fernández-Rodríguez C, Martínez-Cruz LA, Dominici P, Astegno A. Cystathionine β-synthase is involved in cysteine biosynthesis and H 2S generation in Toxoplasma gondii. Sci Rep 2020; 10:14657. [PMID: 32887901 PMCID: PMC7474069 DOI: 10.1038/s41598-020-71469-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 08/11/2020] [Indexed: 11/09/2022] Open
Abstract
Cystathionine β-synthase (CBS) catalyzes the condensation of serine and homocysteine to water and cystathionine, which is then hydrolyzed to cysteine, α-ketobutyrate and ammonia by cystathionine γ-lyase (CGL) in the reverse transsulfuration pathway. The protozoan parasite Toxoplasma gondii, the causative agent of toxoplasmosis, includes both CBS and CGL enzymes. We have recently reported that the putative T. gondii CGL gene encodes a functional enzyme. Herein, we cloned and biochemically characterized cDNA encoding CBS from T. gondii (TgCBS), which represents a first example of protozoan CBS that does not bind heme but possesses two C-terminal CBS domains. We demonstrated that TgCBS can use both serine and O-acetylserine to produce cystathionine, converting these substrates to an aminoacrylate intermediate as part of a PLP-catalyzed β-replacement reaction. Besides a role in cysteine biosynthesis, TgCBS can also efficiently produce hydrogen sulfide, preferentially via condensation of cysteine and homocysteine. Unlike the human counterpart and similar to CBS enzymes from lower organisms, the TgCBS activity is not stimulated by S-adenosylmethionine. This study establishes the presence of an intact functional reverse transsulfuration pathway in T. gondii and demonstrates the crucial role of TgCBS in biogenesis of H2S.
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Affiliation(s)
- Carolina Conter
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy
| | - Silvia Fruncillo
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy.,Manchester Institute of Biotechnology, University of Manchester, 131 Princess Street, Manchester, M1 7DN, UK
| | - Carmen Fernández-Rodríguez
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160, Derio, Spain
| | - Luis Alfonso Martínez-Cruz
- Center for Cooperative Research in Biosciences (CIC bioGUNE), Basque Research and Technology Alliance (BRTA), Bizkaia Technology Park, Building 801A, 48160, Derio, Spain
| | - Paola Dominici
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy
| | - Alessandra Astegno
- Department of Biotechnology, University of Verona, Strada Le Grazie 15, 37134, Verona, Italy.
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15
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González A, Hall MN, Lin SC, Hardie DG. AMPK and TOR: The Yin and Yang of Cellular Nutrient Sensing and Growth Control. Cell Metab 2020; 31:472-492. [PMID: 32130880 DOI: 10.1016/j.cmet.2020.01.015] [Citation(s) in RCA: 394] [Impact Index Per Article: 98.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The AMPK (AMP-activated protein kinase) and TOR (target-of-rapamycin) pathways are interlinked, opposing signaling pathways involved in sensing availability of nutrients and energy and regulation of cell growth. AMPK (Yin, or the "dark side") is switched on by lack of energy or nutrients and inhibits cell growth, while TOR (Yang, or the "bright side") is switched on by nutrient availability and promotes cell growth. Genes encoding the AMPK and TOR complexes are found in almost all eukaryotes, suggesting that these pathways arose very early during eukaryotic evolution. During the development of multicellularity, an additional tier of cell-extrinsic growth control arose that is mediated by growth factors, but these often act by modulating nutrient uptake so that AMPK and TOR remain the underlying regulators of cellular growth control. In this review, we discuss the evolution, structure, and regulation of the AMPK and TOR pathways and the complex mechanisms by which they interact.
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Affiliation(s)
- Asier González
- Biozentrum, University of Basel, CH4056 Basel, Switzerland
| | - Michael N Hall
- Biozentrum, University of Basel, CH4056 Basel, Switzerland
| | - Sheng-Cai Lin
- School of Life Sciences, Xiamen University, Xiamen, 361102 Fujian, China
| | - D Grahame Hardie
- Division of Cell Signalling & Immunology, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, Scotland, UK.
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16
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Phylogeny and Evolution of RNA 3'-Nucleotidyltransferases in Bacteria. J Mol Evol 2019; 87:254-270. [PMID: 31435688 DOI: 10.1007/s00239-019-09907-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Accepted: 08/07/2019] [Indexed: 10/26/2022]
Abstract
The tRNA nucleotidyltransferases and poly(A) polymerases belong to a superfamily of nucleotidyltransferases. The amino acid sequences of a number of bacterial tRNA nucleotidyltransferases and poly(A) polymerases have been used to construct a rooted, neighbor-joining phylogenetic tree. Using information gleaned from that analysis, along with data from the rRNA-based phylogenetic tree, structural data available on a number of members of the superfamily and other biochemical information on the superfamily, it is possible to suggest a scheme for the evolution of the bacterial tRNA nucleotidyltransferases and poly(A) polymerases from ancestral species. Elements of that scheme are discussed along with questions arising from the scheme which can be explored experimentally.
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17
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Vara-Ciruelos D, Russell FM, Hardie DG. The strange case of AMPK and cancer: Dr Jekyll or Mr Hyde? †. Open Biol 2019; 9:190099. [PMID: 31288625 PMCID: PMC6685927 DOI: 10.1098/rsob.190099] [Citation(s) in RCA: 86] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 06/11/2019] [Indexed: 02/06/2023] Open
Abstract
The AMP-activated protein kinase (AMPK) acts as a cellular energy sensor. Once switched on by increases in cellular AMP : ATP ratios, it acts to restore energy homeostasis by switching on catabolic pathways while switching off cell growth and proliferation. The canonical AMP-dependent mechanism of activation requires the upstream kinase LKB1, which was identified genetically to be a tumour suppressor. AMPK can also be switched on by increases in intracellular Ca2+, by glucose starvation and by DNA damage via non-canonical, AMP-independent pathways. Genetic studies of the role of AMPK in mouse cancer suggest that, before disease arises, AMPK acts as a tumour suppressor that protects against cancer, with this protection being further enhanced by AMPK activators such as the biguanide phenformin. However, once cancer has occurred, AMPK switches to being a tumour promoter instead, enhancing cancer cell survival by protecting against metabolic, oxidative and genotoxic stresses. Studies of genetic changes in human cancer also suggest diverging roles for genes encoding subunit isoforms, with some being frequently amplified, while others are mutated.
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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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18
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Willson BJ, Dalzell L, Chapman LNM, Thomas GH. Enhanced functionalisation of major facilitator superfamily transporters via fusion of C-terminal protein domains is both extensive and varied in bacteria. MICROBIOLOGY-SGM 2019; 165:419-424. [PMID: 30657446 DOI: 10.1099/mic.0.000771] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The evolution of gene fusions that result in covalently linked protein domains is widespread in bacteria, where spatially coupling domain functionalities can have functional advantages in vivo. Fusions to integral membrane proteins are less widely studied but could provide routes to enhance membrane function in synthetic biology. We studied the major facilitator superfamily (MFS), as the largest family of transporter proteins in bacteria, to examine the extent and nature of fusions to these proteins. A remarkably diverse variety of fusions are identified and the 8 most abundant examples are described, including additional enzymatic domains and a range of sensory and regulatory domains, many not previously described. Significantly, these fusions are found almost exclusively as C-terminal fusions, revealing that the usually cytoplasmic C-terminal end of MFS protein would the permissive end for engineering synthetic fusions to other cytoplasmic proteins.
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Affiliation(s)
- Benjamin J Willson
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Lindsey Dalzell
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Liam N M Chapman
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Gavin H Thomas
- Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
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19
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Sekowska A, Ashida H, Danchin A. Revisiting the methionine salvage pathway and its paralogues. Microb Biotechnol 2019; 12:77-97. [PMID: 30306718 PMCID: PMC6302742 DOI: 10.1111/1751-7915.13324] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 08/24/2018] [Accepted: 09/14/2018] [Indexed: 12/17/2022] Open
Abstract
Methionine is essential for life. Its chemistry makes it fragile in the presence of oxygen. Aerobic living organisms have selected a salvage pathway (the MSP) that uses dioxygen to regenerate methionine, associated to a ratchet-like step that prevents methionine back degradation. Here, we describe the variation on this theme, developed across the tree of life. Oxygen appeared long after life had developed on Earth. The canonical MSP evolved from ancestors that used both predecessors of ribulose bisphosphate carboxylase oxygenase (RuBisCO) and methanethiol in intermediate steps. We document how these likely promiscuous pathways were also used to metabolize the omnipresent by-products of S-adenosylmethionine radical enzymes as well as the aromatic and isoprene skeleton of quinone electron acceptors.
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Affiliation(s)
- Agnieszka Sekowska
- Institute of Cardiometabolism and NutritionHôpital de la Pitié‐SalpêtrièreParisFrance
| | - Hiroki Ashida
- Graduate School of Human Development and EnvironmentKobe UniversityKobeJapan
| | - Antoine Danchin
- Institute of Cardiometabolism and NutritionHôpital de la Pitié‐SalpêtrièreParisFrance
- Institute of Synthetic BiologyShenzhen Institutes of Advanced StudiesShenzhenChina
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20
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Giménez-Mascarell P, Majtan T, Oyenarte I, Ereño-Orbea J, Majtan J, Klaudiny J, Kraus JP, Martínez-Cruz LA. Crystal structure of cystathionine β-synthase from honeybee Apis mellifera. J Struct Biol 2017; 202:82-93. [PMID: 29275181 DOI: 10.1016/j.jsb.2017.12.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 11/28/2017] [Accepted: 12/19/2017] [Indexed: 11/26/2022]
Abstract
Cystathionine β-synthase (CBS), the key enzyme in the transsulfuration pathway, links methionine metabolism to the biosynthesis of cellular redox controlling molecules. CBS catalyzes the pyridoxal-5'-phosphate-dependent condensation of serine and homocysteine to form cystathionine, which is subsequently converted into cysteine. Besides maintaining cellular sulfur amino acid homeostasis, CBS also catalyzes multiple hydrogen sulfide-generating reactions using cysteine and homocysteine as substrates. In mammals, CBS is activated by S-adenosylmethionine (AdoMet), where it can adopt two different conformations (basal and activated), but exists as a unique highly active species in fruit fly Drosophila melanogaster. Here we present the crystal structure of CBS from honeybey Apis mellifera, which shows a constitutively active dimeric species and let explain why the enzyme is not allosterically regulated by AdoMet. In addition, comparison of available CBS structures unveils a substrate-induced closure of the catalytic cavity, which in humans is affected by the AdoMet-dependent regulation and likely impaired by the homocystinuria causing mutation T191M.
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Affiliation(s)
- Paula Giménez-Mascarell
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC Biogune), Technology Park of Bizkaia, 48160 Derio, Bizkaia, Spain
| | - Tomas Majtan
- Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO 80045, USA
| | - Iker Oyenarte
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC Biogune), Technology Park of Bizkaia, 48160 Derio, Bizkaia, Spain
| | - June Ereño-Orbea
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC Biogune), Technology Park of Bizkaia, 48160 Derio, Bizkaia, Spain
| | - Juraj Majtan
- Laboratory of Apidology and Apitherapy, Institute of Molecular Biology, Slovak Academy of Sciences, Bratislava 84551, Slovakia
| | - Jaroslav Klaudiny
- Department of Glycobiology, Institute of Chemistry, Slovak Academy of Sciences, Bratislava 84538, Slovakia
| | - Jan P Kraus
- Department of Pediatrics, School of Medicine, University of Colorado, Aurora, CO 80045, USA
| | - Luis Alfonso Martínez-Cruz
- Structural Biology Unit, Center for Cooperative Research in Biosciences (CIC Biogune), Technology Park of Bizkaia, 48160 Derio, Bizkaia, Spain.
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