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Hnízda A, Škerlová J, Fábry M, Pachl P, Šinalová M, Vrzal L, Man P, Novák P, Řezáčová P, Veverka V. Oligomeric interface modulation causes misregulation of purine 5´-nucleotidase in relapsed leukemia. BMC Biol 2016; 14:91. [PMID: 27756303 PMCID: PMC5070119 DOI: 10.1186/s12915-016-0313-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Accepted: 09/23/2016] [Indexed: 11/10/2022] Open
Abstract
Background Relapsed acute lymphoblastic leukemia (ALL) is one of the main causes of mortality in childhood malignancies. Previous genetic studies demonstrated that chemoresistant ALL is driven by activating mutations in NT5C2, the gene encoding cytosolic 5´-nucleotidase (cN-II). However, molecular mechanisms underlying this hyperactivation are still unknown. Here, we present kinetic and structural properties of cN-II variants that represent 75 % of mutated alleles in patients who experience relapsed ALL (R367Q, R238W and L375F). Results Enzyme kinetics measurements revealed that the mutants are consitutively active without need for allosteric activators. This shows that hyperactivity is not caused by a direct catalytic effect but rather by misregulation of cN-II. X-ray crystallography combined with mass spectrometry-based techniques demonstrated that this misregulation is driven by structural modulation of the oligomeric interface within the cN-II homotetrameric assembly. These specific conformational changes are shared between the studied variants, despite the relatively random spatial distribution of the mutations. Conclusions These findings define a common molecular mechanism for cN-II hyperactivity, which provides a solid basis for targeted therapy of leukemia. Our study highlights the cN-II oligomerization interface as an attractive pharmacological target. Electronic supplementary material The online version of this article (doi:10.1186/s12915-016-0313-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Aleš Hnízda
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic.
| | - Jana Škerlová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic
| | - Milan Fábry
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Petr Pachl
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic
| | - Martina Šinalová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic
| | - Lukáš Vrzal
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic
| | - Petr Man
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Petr Novák
- Institute of Microbiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Pavlína Řezáčová
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic.,Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 4, 142 20, Czech Republic
| | - Václav Veverka
- Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 6, 166 10, Czech Republic.
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Nguyen Van T, Hospital A, Lionne C, Jordheim LP, Dumontet C, Périgaud C, Chaloin L, Peyrottes S. Beta-hydroxyphosphonate ribonucleoside analogues derived from 4-substituted-1,2,3-triazoles as IMP/GMP mimics: synthesis and biological evaluation. Beilstein J Org Chem 2016; 12:1476-86. [PMID: 27559400 PMCID: PMC4979751 DOI: 10.3762/bjoc.12.144] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2016] [Accepted: 06/27/2016] [Indexed: 11/26/2022] Open
Abstract
A series of seventeen β-hydroxyphosphonate ribonucleoside analogues containing 4-substituted-1,2,3-triazoles was synthesized and fully characterized. Such compounds were designed as potential inhibitors of the cytosolic 5'-nucleotidase II (cN-II), an enzyme involved in the regulation of purine nucleotide pools. NMR and molecular modelling studies showed that a few derivatives adopted similar structural features to IMP or GMP. Five derivatives were identified as modest inhibitors with 53 to 64% of cN-II inhibition at 1 mM.
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Affiliation(s)
- Tai Nguyen Van
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS – Université de Montpellier - ENSCM, Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier, France
| | - Audrey Hospital
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS – Université de Montpellier - ENSCM, Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier, France
| | - Corinne Lionne
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), FRE 3689 CNRS - Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Lars P Jordheim
- Université de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France
| | - Charles Dumontet
- Université de Lyon, Université Claude Bernard Lyon 1, INSERM 1052, CNRS 5286, Centre Léon Bérard, Centre de Recherche en Cancérologie de Lyon, 69008 Lyon, France
| | - Christian Périgaud
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS – Université de Montpellier - ENSCM, Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier, France
| | - Laurent Chaloin
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), FRE 3689 CNRS - Université de Montpellier, 1919 route de Mende, 34293 Montpellier, France
| | - Suzanne Peyrottes
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS – Université de Montpellier - ENSCM, Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier, France
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3
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Marton Z, Guillon R, Krimm I, Preeti, Rahimova R, Egron D, Jordheim LP, Aghajari N, Dumontet C, Périgaud C, Lionne C, Peyrottes S, Chaloin L. Identification of Noncompetitive Inhibitors of Cytosolic 5'-Nucleotidase II Using a Fragment-Based Approach. J Med Chem 2015; 58:9680-96. [PMID: 26599519 DOI: 10.1021/acs.jmedchem.5b01616] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We used a combined approach based on fragment-based drug design (FBDD) and in silico methods to design potential inhibitors of the cytosolic 5'-nucleotidase II (cN-II), which has been recognized as an important therapeutic target in hematological cancers. Two subgroups of small compounds (including adenine and biaryl moieties) were identified as cN-II binders and a fragment growing strategy guided by molecular docking was considered. Five compounds induced a strong inhibition of the 5'-nucleotidase activity in vitro, and the most potent ones were characterized as noncompetitive inhibitors. Biological evaluation in cancer cell lines showed synergic effect with selected anticancer drugs. Structural studies using X-ray crystallography lead to the identification of new binding sites for two derivatives and of a new crystal form showing important domain swapping. Altogether, the strategy developed herein allowed identifying new original noncompetitive inhibitors against cN-II that act in a synergistic manner with well-known antitumoral agents.
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Affiliation(s)
- Zsuzsanna Marton
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), FRE 3689 CNRS, Université de Montpellier , 1919 route de Mende, 34293 Montpellier cedex 5, France
| | - Rémi Guillon
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS, Université de Montpellier, ENSCM , Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier cedex 5, France
| | - Isabelle Krimm
- Institut des Sciences Analytiques, UMR 5280 CNRS, Université Lyon 1 , ENS de Lyon, 5 rue de la Doua, 69100 Villeurbanne, France
| | - Preeti
- Institut de Biologie et Chimie des Protéines FR3302, Molecular and Structural Bases of Infectious Diseases UMR 5086 CNRS, Université Lyon 1 , 7 Passage du Vercors, 69367 Lyon, France
| | - Rahila Rahimova
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), FRE 3689 CNRS, Université de Montpellier , 1919 route de Mende, 34293 Montpellier cedex 5, France
| | - David Egron
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS, Université de Montpellier, ENSCM , Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier cedex 5, France
| | - Lars P Jordheim
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR 5286, Centre Léon Bérard, Université Lyon 1 , 69008 Lyon, France
| | - Nushin Aghajari
- Institut de Biologie et Chimie des Protéines FR3302, Molecular and Structural Bases of Infectious Diseases UMR 5086 CNRS, Université Lyon 1 , 7 Passage du Vercors, 69367 Lyon, France
| | - Charles Dumontet
- Centre de Recherche en Cancérologie de Lyon, INSERM U1052, CNRS UMR 5286, Centre Léon Bérard, Université Lyon 1 , 69008 Lyon, France
| | - Christian Périgaud
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS, Université de Montpellier, ENSCM , Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier cedex 5, France
| | - Corinne Lionne
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), FRE 3689 CNRS, Université de Montpellier , 1919 route de Mende, 34293 Montpellier cedex 5, France
| | - Suzanne Peyrottes
- Institut des Biomolécules Max Mousseron (IBMM), UMR 5247 CNRS, Université de Montpellier, ENSCM , Campus Triolet, cc1705, Place Eugène Bataillon, 34095 Montpellier cedex 5, France
| | - Laurent Chaloin
- Centre d'études d'agents Pathogènes et Biotechnologies pour la Santé (CPBS), FRE 3689 CNRS, Université de Montpellier , 1919 route de Mende, 34293 Montpellier cedex 5, France
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Cividini F, Cros-Perrial E, Pesi R, Machon C, Allegrini S, Camici M, Dumontet C, Jordheim LP, Tozzi MG. Cell proliferation and drug sensitivity of human glioblastoma cells are altered by the stable modulation of cytosolic 5'-nucleotidase II. Int J Biochem Cell Biol 2015; 65:222-9. [PMID: 26079827 DOI: 10.1016/j.biocel.2015.06.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 05/31/2015] [Accepted: 06/08/2015] [Indexed: 01/13/2023]
Abstract
Cytosolic 5'-nucleotidase II (cN-II) has been reported to be involved in cell survival, nucleotide metabolism and in the cellular response to anticancer drugs. With the aim to further evaluate the role of this enzyme in cell biology, we stably modulated its expression the human glioblastoma cell ADF in which the transient inhibition of cN-II has been shown to induce cell death. Stable cell lines were obtained both with inhibition, obtained with plasmids coding cN-II-targeting short hairpin RNA, and stimulation, obtained with plasmids coding Green Fluorescence Protein (GFP)-fused wild type cN-II or a GFP-fused hyperactive mutant (GFP-cN-II-R367Q), of cN-II expression. Silenced cells displayed a decreased proliferation rate while the over expressing cell lines displayed an increased proliferation rate as evidenced by impedance measurement using the xCELLigence device. The expression of nucleotide metabolism relevant genes was only slightly different between cell lines, suggesting a compensatory mechanism in transfected cells. Cells with decreased cN-II expression were resistant to the nucleoside analog fludarabine confirming the involvement of cN-II in the metabolism of this drug. Finally, we observed sensitivity to cisplatin in cN-II silenced cells and resistance to this same drug in cN-II over-expressing cells indicating an involvement of cN-II in the mechanism of action of platinum derivatives, and most probably in DNA repair. In summary, our findings confirm some previous data on the role of cN-II in the sensitivity of cancer cells to cancer drugs, and suggest its involvement in other cellular phenomenon such as cell proliferation.
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Affiliation(s)
- F Cividini
- University of Pisa, Department of Biology, Biochemistry Unit, Pisa, Italy.
| | - E Cros-Perrial
- Université de Lyon, F-69000 Lyon, France; Université de Lyon 1, F-69622 Lyon, France; Université de Lyon 1, F-69000 Lyon, France; INSERM U1052, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France; CNRS UMR 5286, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
| | - R Pesi
- University of Pisa, Department of Biology, Biochemistry Unit, Pisa, Italy
| | - C Machon
- Hospices Civils de Lyon, Centre Hospitalier Lyon-Sud, Laboratoire de Biochimie et Toxicologie, Lyon, France
| | - S Allegrini
- University of Sassari, Department of Chemistry and Pharmacology, Sassari, Italy
| | - M Camici
- University of Pisa, Department of Biology, Biochemistry Unit, Pisa, Italy
| | - C Dumontet
- Université de Lyon, F-69000 Lyon, France; Université de Lyon 1, F-69622 Lyon, France; Université de Lyon 1, F-69000 Lyon, France; INSERM U1052, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France; CNRS UMR 5286, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
| | - L P Jordheim
- Université de Lyon, F-69000 Lyon, France; Université de Lyon 1, F-69622 Lyon, France; Université de Lyon 1, F-69000 Lyon, France; INSERM U1052, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France; CNRS UMR 5286, Centre de Recherche en Cancérologie de Lyon, F-69000 Lyon, France
| | - M G Tozzi
- University of Pisa, Department of Biology, Biochemistry Unit, Pisa, Italy
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Cytosolic 5'-nucleotidase II interacts with the leucin rich repeat of NLR family member Ipaf. PLoS One 2015; 10:e0121525. [PMID: 25811392 PMCID: PMC4374842 DOI: 10.1371/journal.pone.0121525] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 02/03/2015] [Indexed: 01/17/2023] Open
Abstract
IMP/GMP preferring cytosolic 5'-nucleotidase II (cN-II) is a bifunctional enzyme whose activities and expression play crucial roles in nucleotide pool maintenance, nucleotide-dependent pathways and programmed cell death. Alignment of primary amino acid sequences of cN-II from human and other organisms show a strong conservation throughout the entire vertebrata taxon suggesting a fundamental role in eukaryotic cells. With the aim to investigate the potential role of this homology in protein-protein interactions, a two hybrid system screening of cN-II interactors was performed in S. cerevisiae. Among the X positive hits, the Leucin Rich Repeat (LRR) domain of Ipaf was found to interact with cN-II. Recombinant Ipaf isoform B (lacking the Nucleotide Binding Domain) was used in an in vitro affinity chromatography assay confirming the interaction obtained in the screening. Moreover, co-immunoprecipitation with proteins from wild type Human Embryonic Kidney 293 T cells demonstrated that endogenous cN-II co-immunoprecipitated both with wild type Ipaf and its LRR domain after transfection with corresponding expression vectors, but not with Ipaf lacking the LRR domain. These results suggest that the interaction takes place through the LRR domain of Ipaf. In addition, a proximity ligation assay was performed in A549 lung carcinoma cells and in MDA-MB-231 breast cancer cells and showed a positive cytosolic signal, confirming that this interaction occurs in human cells. This is the first report of a protein-protein interaction involving cN-II, suggesting either novel functions or an additional level of regulation of this complex enzyme.
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Cividini F, Pesi R, Chaloin L, Allegrini S, Camici M, Cros-Perrial E, Dumontet C, Jordheim L, Tozzi M. The purine analog fludarabine acts as a cytosolic 5′-nucleotidase II inhibitor. Biochem Pharmacol 2015; 94:63-8. [DOI: 10.1016/j.bcp.2015.01.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Revised: 01/26/2015] [Accepted: 01/26/2015] [Indexed: 11/29/2022]
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Kestler C, Knobloch G, Tessmer I, Jeanclos E, Schindelin H, Gohla A. Chronophin dimerization is required for proper positioning of its substrate specificity loop. J Biol Chem 2013; 289:3094-103. [PMID: 24338687 DOI: 10.1074/jbc.m113.536482] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mammalian phosphatases of the haloacid dehalogenase (HAD) superfamily have emerged as important regulators of physiology and disease. Many of these enzymes are stable homodimers; however, the role of their dimerization is largely unknown. Here, we explore the function of the obligatory homodimerization of chronophin, a mammalian HAD phosphatase known to dephosphorylate pyridoxal 5'-phosphate (PLP) and serine/threonine-phosphorylated proteins. The exchange of two residues in the murine chronophin homodimerization interface (chronophin(A194K,A195K)) yields a constitutive monomer both in vitro and in cells. The catalytic activity of monomeric chronophin toward PLP is strongly impaired. X-ray crystallographic studies of chronophin(A194K,A195K) revealed that dimer formation is essential for an intermolecular arginine-arginine-tryptophan stacking interaction that positions a critical histidine residue in the substrate specificity loop of chronophin for PLP coordination. Analysis of all available crystal structures of HAD hydrolases that are grouped together with chronophin in the C2a-type structural subfamily uncovered a highly conserved mode of dimerization that results in intermolecular contacts involving the substrate specificity loop. Our results explain how the dimerization of HAD hydrolases contributes to their catalytic efficiency and substrate specificity.
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Affiliation(s)
- Christian Kestler
- From the Institute for Pharmacology and Toxicology, University of Würzburg, 97078 Würzburg, Germany and
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al-Rashida M, Iqbal J. Therapeutic potentials of ecto-nucleoside triphosphate diphosphohydrolase, ecto-nucleotide pyrophosphatase/phosphodiesterase, ecto-5'-nucleotidase, and alkaline phosphatase inhibitors. Med Res Rev 2013; 34:703-43. [PMID: 24115166 DOI: 10.1002/med.21302] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The modulatory role of extracellular nucleotides and adenosine in relevance to purinergic cell signaling mechanisms has long been known and is an object of much research worldwide. These extracellular nucleotides are released by a variety of cell types either innately or as a response to patho-physiological stress or injury. A variety of surface-located ecto-nucleotidases (of four major types; nucleoside triphosphate diphosphohydrolases or NTPDases, nucleotide pyrophosphatase/phosphodiesterases or NPPs, alkaline phosphatases APs or ALPs, and ecto-5'-nucleotidase or e5NT) are responsible for meticulously controlling the availability of these important signaling molecules (at their respective receptors) in extracellular environment and are therefore crucial for maintaining the integrity of normal cell functioning. Overexpression of many of these ubiquitous ecto-enzymes has been implicated in a variety of disorders including cell adhesion, activation, proliferation, apoptosis, and degenerative neurological and immunological responses. Selective inhibition of these ecto-enzymes is an area that is currently being explored with great interest and hopes remain high that development of selective ecto-nucleotidase inhibitors will prove to have many beneficial therapeutic implications. The aim of this review is to emphasize and focus on recent developments made in the field of inhibitors of ecto-nucleotidases and to highlight their structure activity relationships wherever possible. Most recent and significant advances in field of NTPDase, NPP, AP, and e5NT inhibitors is being discussed in detail in anticipation of providing prolific leads and relevant background for research groups interested in synthesis of selective ecto-nucleotidase inhibitors.
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Affiliation(s)
- Mariya al-Rashida
- Department of Pharmaceutical Sciences, COMSATS Institute of Information Technology, Abbottabad, 22060, Pakistan
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Filoni DN, Pesi R, Allegrini S, Camici M, Tozzi MG. A native electrophoretic technique to study oligomerization and activity of cytosolic 5′-nucleotidase II. Anal Bioanal Chem 2013; 405:8951-4. [DOI: 10.1007/s00216-013-7313-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Accepted: 08/15/2013] [Indexed: 11/28/2022]
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Jordheim LP, Marton Z, Rhimi M, Cros-Perrial E, Lionne C, Peyrottes S, Dumontet C, Aghajari N, Chaloin L. Identification and characterization of inhibitors of cytoplasmic 5′-nucleotidase cN-II issued from virtual screening. Biochem Pharmacol 2013; 85:497-506. [DOI: 10.1016/j.bcp.2012.11.024] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/29/2012] [Accepted: 11/29/2012] [Indexed: 02/01/2023]
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Voigt A, Schöfl G, Saluz HP. The Chlamydia psittaci genome: a comparative analysis of intracellular pathogens. PLoS One 2012; 7:e35097. [PMID: 22506068 PMCID: PMC3323650 DOI: 10.1371/journal.pone.0035097] [Citation(s) in RCA: 81] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 03/08/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Chlamydiaceae are a family of obligate intracellular pathogens causing a wide range of diseases in animals and humans, and facing unique evolutionary constraints not encountered by free-living prokaryotes. To investigate genomic aspects of infection, virulence and host preference we have sequenced Chlamydia psittaci, the pathogenic agent of ornithosis. RESULTS A comparison of the genome of the avian Chlamydia psittaci isolate 6BC with the genomes of other chlamydial species, C. trachomatis, C. muridarum, C. pneumoniae, C. abortus, C. felis and C. caviae, revealed a high level of sequence conservation and synteny across taxa, with the major exception of the human pathogen C. trachomatis. Important differences manifest in the polymorphic membrane protein family specific for the Chlamydiae and in the highly variable chlamydial plasticity zone. We identified a number of psittaci-specific polymorphic membrane proteins of the G family that may be related to differences in host-range and/or virulence as compared to closely related Chlamydiaceae. We calculated non-synonymous to synonymous substitution rate ratios for pairs of orthologous genes to identify putative targets of adaptive evolution and predicted type III secreted effector proteins. CONCLUSIONS This study is the first detailed analysis of the Chlamydia psittaci genome sequence. It provides insights in the genome architecture of C. psittaci and proposes a number of novel candidate genes mostly of yet unknown function that may be important for pathogen-host interactions.
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Affiliation(s)
- Anja Voigt
- Leibniz-Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Gerhard Schöfl
- Leibniz-Institute for Natural Product Research and Infection Biology, Jena, Germany
| | - Hans Peter Saluz
- Leibniz-Institute for Natural Product Research and Infection Biology, Jena, Germany
- Friedrich Schiller University, Jena, Germany
- * E-mail:
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Grazia TM. Inborn errors in purine metabolism: role of 5'-nucleotidases and their involvement in the etiology of neurological impairments. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2012; 30:1276-83. [PMID: 22132987 DOI: 10.1080/15257770.2011.616869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
A number of scientists have been involved for decades in the study of nucleotide metabolism in different species of living beings. We are, therefore, aware of the relevant roles of purine compounds and of the many different ways in which these compounds influence cell life, acting both inside and outside the cells. Nevertheless, the consequences of an alteration (lack of expression, or hypo- or hyperexpression) in the activity of enzymes involved in the metabolism of these compounds are sometimes surprising, and far from being mechanistically explained. Alterations in enzyme activities involved in nucleotide metabolism are frequently associated with syndromes characterized by two different types of problems--one, metabolic, which is expected and can be easily explained, and the second, neurological and behavioral. Neurological and behavioral impairments are more difficult to explain and show a very high degree of individual variability. The molecular bases of the neurological impairment linked to purine metabolism disorders have been extensively studied. These studies have generated a lot of hypotheses but very few certainties. In this short review, neurological and behavioral symptoms linked to the dysfunction of some enzymes involved in purine synthesis, catabolism, and salvage will be briefly described, with particular attention to their metabolic and regulatory consequences. Finally, attention will be focused on the 5'-nucleotidase family members and on their involvement in the regulation of purine and pyrimidine metabolism.
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Filoni DN, Pesi R, Careddu MG, Camici M, Allegrini S, Collavoli A, Scarfone I, Zucchi F, Galli A, Tozzi MG. Initial studies to define the physiologic role of cN-II. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2012; 30:1155-60. [PMID: 22132970 DOI: 10.1080/15257770.2011.628355] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
IMP preferring cytosolic 5'-nucleotidase II (cN-II) is a widespread enzyme whose amino acid sequence is highly conserved among vertebrates. Fluctuations of its activity have been reported in some pathological conditions and its mRNA levels have been proposed as a prognostic factor for poor outcome in patients with adult acute myeloid leukemia. As a member of the oxypurine cycle, cN-II is involved in the regulation of intracellular concentration of 5'-inosine monophosphate (IMP), 5'-guanosine monophosphate (GMP), and also 5-phosphoribose 1-pyrophosphate (PRPP) and is therefore involved in the regulation of purine and pyrimidine de novo and salvage synthesis. In addition, several studies demonstrated the involvement of cN-II in pro-drug metabolism. Notwithstanding some publications indicating that cN-II is essential for the survival of several cell types, its role in cell metabolism remains uncertain. To address this issue, we built two eucaryotic cellular models characterized by different cN-II expression levels: a constitutive cN-II knockdown in the astrocytoma cell line (ADF) by short hairpin RNA (shRNA) strategy and a cN-II expression in the diploid strain RS112 of Saccharomyces cerevisiae. Preliminary results suggest that cN-II is essential for cell viability, probably because it is directly involved in the regulation of nucleotide pools. These two experimental approaches could be very useful for the design of a personalized chemotherapy.
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