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Kardoost A, Schönherr R, Deiter C, Redecke L, Lorenzen K, Schulz J, de Diego I. Convolutional neural network approach for the automated identification of in cellulo crystals. J Appl Crystallogr 2024; 57:266-275. [PMID: 38596734 PMCID: PMC11001417 DOI: 10.1107/s1600576724000682] [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: 03/22/2023] [Accepted: 01/18/2024] [Indexed: 04/11/2024] Open
Abstract
In cellulo crystallization is a rare event in nature. Recent advances that have made use of heterologous overexpression can promote the intracellular formation of protein crystals, but new tools are required to detect and characterize these targets in the complex cell environment. The present work makes use of Mask R-CNN, a convolutional neural network (CNN)-based instance segmentation method, for the identification of either single or multi-shaped crystals growing in living insect cells, using conventional bright field images. The algorithm can be rapidly adapted to recognize different targets, with the aim of extracting relevant information to support a semi-automated screening pipeline, in order to aid the development of the intracellular protein crystallization approach.
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Affiliation(s)
- Amirhossein Kardoost
- Sample Environment and Characterization Group, European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Schleswig-Holstein, Germany
| | - Robert Schönherr
- Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Schleswig-Holstein, Germany
| | - Carsten Deiter
- Sample Environment and Characterization Group, European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Schleswig-Holstein, Germany
| | - Lars Redecke
- Institute of Biochemistry, University of Lübeck, Ratzeburger Allee 160, 23562 Lübeck, Schleswig-Holstein, Germany
- Deutsches Elektronen-Synchrotron DESY, Photon Science, Notkestrasse 85, 22607 Hamburg, Germany
| | - Kristina Lorenzen
- Sample Environment and Characterization Group, European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Schleswig-Holstein, Germany
| | - Joachim Schulz
- Sample Environment and Characterization Group, European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Schleswig-Holstein, Germany
| | - Iñaki de Diego
- Sample Environment and Characterization Group, European XFEL GmbH, Holzkoppel 4, 22869 Schenefeld, Schleswig-Holstein, Germany
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Hernández-Gómez A, Irisarri I, Fernández-Justel D, Peláez R, Jiménez A, Revuelta JL, Balsera M, Buey RM. GuaB3, an overlooked enzyme in cyanobacteria's toolbox that sheds light on IMP dehydrogenase evolution. Structure 2023; 31:1526-1534.e4. [PMID: 37875114 DOI: 10.1016/j.str.2023.09.014] [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: 07/11/2023] [Revised: 09/05/2023] [Accepted: 09/28/2023] [Indexed: 10/26/2023]
Abstract
IMP dehydrogenase and GMP reductase are enzymes from the same protein family with analogous structures and catalytic mechanisms that have gained attention because of their essential roles in nucleotide metabolism and as potential drug targets. This study focusses on GuaB3, a less-explored enzyme within this family. Phylogenetic analysis uncovers GuaB3's independent evolution from other members of the family and it predominantly occurs in Cyanobacteria. Within this group, GuaB3 functions as a unique IMP dehydrogenase, while its counterpart in Actinobacteria has a yet unknown function. Synechocystis sp. PCC6803 GuaB3 structures demonstrate differences in the active site compared to canonical IMP dehydrogenases, despite shared catalytic mechanisms. These findings highlight the essential role of GuaB3 in Cyanobacteria, provide insights into the diversity and evolution of the IMP dehydrogenase protein family, and reveal a distinctive characteristic in nucleotide metabolism, potentially aiding in combating harmful cyanobacterial blooms-a growing concern for humans and wildlife.
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Affiliation(s)
- Alejandro Hernández-Gómez
- Metabolic Engineering Group, Dpto. Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Iker Irisarri
- Section Phylogenomics, Centre for Molecular Biodiversity Research, Leibniz Institute for the Analysis of Biodiversity Change (LIB), Museum of Nature Hamburg, Martin-Luther-King-Platz 3, 20146 Hamburg, Germany
| | - David Fernández-Justel
- Metabolic Engineering Group, Dpto. Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Rafael Peláez
- Laboratorio de Química Orgánica y Farmacéutica, Dpto. Ciencias Farmacéuticas, Universidad de Salamanca, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Alberto Jiménez
- Metabolic Engineering Group, Dpto. Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - José Luis Revuelta
- Metabolic Engineering Group, Dpto. Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007 Salamanca, Spain
| | - Mónica Balsera
- Department Abiotic Stress, Instituto de Recursos Naturales y Agrobiología (IRNASA-CSIC), Cordel de Merinas 40-52, 37008 Salamanca, Spain
| | - Rubén M Buey
- Metabolic Engineering Group, Dpto. Microbiología y Genética, Universidad de Salamanca, Edificio Departamental, Campus Miguel de Unamuno, 37007 Salamanca, Spain.
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Zhang X, Han L, Zhang H, Niu Y, Liang R. Identification of potential key genes of TGF-beta signaling associated with the immune response and prognosis of ovarian cancer based on bioinformatics analysis. Heliyon 2023; 9:e19208. [PMID: 37664697 PMCID: PMC10469581 DOI: 10.1016/j.heliyon.2023.e19208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Revised: 08/11/2023] [Accepted: 08/16/2023] [Indexed: 09/05/2023] Open
Abstract
Background TGF-beta signaling is a key regulator of immunity and multiple cellular behaviors in cancer. However, the prognostic and therapeutic role of TGF-beta signaling-related genes in ovarian cancer (OV) remains unexplored. Methods Data of OV used in the current study were sourced from TCGA and GEO databases. Consensus clustering was applied to classify OV patients into different clusters using TGF-beta signaling-related genes. Differentially expressed genes (DEGs) between different clusters were screened by the "limma" R package. Prognostic genes were screened from DEGs by univariate Cox regression, followed by the construction of the TGF-beta signaling-related score. The prognostic value of TGF-beta signaling-related score was evaluated in both training and testing OV cohorts. Moreover, the immune status, GSEA and therapeutic response between low- and high-score groups were performed to further reveal the potential mechanisms. Results By consensus clustering, OV patients were classified into two clusters with different tumor immune environments. After differential expression and univariate Cox regression analyses, GMPR, PIEZO1, EMP1, CXCL13, GADD45B, SORCS2, FOSL2, PODN, LYNX1 and SLC38A5 were selected as prognostic genes. Using PCA algorithm, the TGF-beta signaling-related score of OV patients was calculated based on prognostic genes. Then OV patients were divided into low- and high-TGF-beta signaling-related score groups. We observed that the two score groups had significantly different survivals, tumor immune environments and expressions of immune checkpoints. In addition, GSEA results showed that immune-related pathways and biological processes, like chemokine signaling pathway, TNF signaling pathway and T cell migration were significantly enriched in the low-score group. Moreover, patients in the low- and high-score groups had remarkably different sensitivity to chemo- and immunotherapy. Conclusion For the first time, our study identified ten prognostic genes associated with TGF-beta signaling, constructed a prognostic TGF-beta signaling-related score and investigated the effect of TGF-beta signaling-related score on OV immunity and therapy. These findings may enrich our knowledge of the TGF-beta signaling in OV prognosis and help to improve the prognosis prediction and treatment strategies in OV.
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Affiliation(s)
- Xiaoxue Zhang
- Department of Physical Examination, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Liping Han
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Huimin Zhang
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Yameng Niu
- Department of Physical Examination, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
| | - Ruopeng Liang
- Department of Hepatobiliary and Pancreatic Surgery, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, PR China
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Gaiya DD, Muhammad A, Aimola IA, Udu SK, Balarabe SA, Auta R, Ekpa E, Sheyin A. Potential of Onchocerca ochengi inosine-5'-monophosphate dehydrogenase (IMPDH) and guanosine-5'-monophosphate oxidoreductase (GMPR) as druggable and vaccine candidates: immunoinformatics screening. J Biomol Struct Dyn 2023; 41:14832-14848. [PMID: 36866624 DOI: 10.1080/07391102.2023.2184171] [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: 08/29/2022] [Accepted: 02/18/2023] [Indexed: 03/04/2023]
Abstract
Onchocerciasis is a vector-borne disease caused by the filarial nematode Onchocerca volvulus, which is responsible for most of the visual impairments recorded in Africa, Asia and the Americas. It is known that O. volvulus has similar molecular and biological characteristics as Onchocerca ochengi in cattle. This study was designed to screen for immunogenic epitopes and binding pockets of O. ochengi IMPDH and GMPR ligands using immunoinformatic approaches. In this study, a total of 23 B cell epitopes for IMPDH and 7 B cell epitopes for GMPR were predicted using ABCpred tool, Bepipred 2.0 and Kolaskar and Tongaonkar methods. The CD4+ Th computational results showed 16 antigenic epitopes from IMPDH with strong binding affinity for DRB1_0301, DRB3_0101, DRB1_0103 and DRB1_1501 MHC II alleles while 8 antigenic epitopes from GMPR were predicted to bind DRB1_0101 and DRB1_0401 MHC II alleles, respectively. For the CD8+ CTLs analysis, 8 antigenic epitopes from IMPDH showed strong binding affinity to human leukocyte antigen HLA-A*26:01, HLA-A*03:01, HLA-A*24:02 and HLA-A*01:01 MHC I alleles while 2 antigenic epitopes from GMPR showed strong binding affinity to HLA-A*01:01 allele, respectively. The immunogenic B cell and T cell epitopes were further evaluated for antigenicity, non-alllergernicity, toxicity, IFN-gamma, IL4 and IL10. The docking score revealed favorable binding free energy with IMP and MYD scoring the highest binding affinity at -6.6 kcal/mol with IMPDH and -8.3 kcal/mol with GMPR. This study provides valuable insight on IMPDH and GMPR as potential drug targets and for the development of multiple epitope vaccine candidates.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Daniel Danladi Gaiya
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Aliyu Muhammad
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Idowu Asegame Aimola
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Stella Kuyet Udu
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Sallau Abdullahi Balarabe
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
| | - Richard Auta
- Department of Biochemistry, Faculty of Science, Kaduna State University, Kaduna, Kaduna State, Nigeria
| | - Emmanuel Ekpa
- Biology Unit, Faculty of Science, Air Force Institute of Technology, Nigerian Air Force Base, Kawo, Kaduna State, Nigeria
| | - Abraham Sheyin
- Department of Biochemistry, Faculty of Life Sciences, Ahmadu Bello University, Samaru Zaria, Kaduna State, Nigeria
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Knejzlík Z, Doležal M, Herkommerová K, Clarova K, Klíma M, Dedola M, Zborníková E, Rejman D, Pichová I. The mycobacterial guaB1 gene encodes a guanosine 5'-monophosphate reductase with a cystathionine-β-synthase domain. FEBS J 2022; 289:5571-5598. [PMID: 35338694 PMCID: PMC9790621 DOI: 10.1111/febs.16448] [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: 09/06/2021] [Revised: 02/11/2022] [Accepted: 03/24/2022] [Indexed: 12/30/2022]
Abstract
Mycobacteria express enzymes from both the de novo and purine-salvage pathways. However, the regulation of these processes and the roles of individual metabolic enzymes have not been sufficiently detailed. Both Mycobacterium tuberculosis (Mtb) and Mycobacterium smegmatis (Msm) possess three guaB genes, but information is only available on guaB2, which encodes an essential inosine 5'-monophosphate dehydrogenase (IMPDH) involved in de novo purine biosynthesis. This study shows that guaB1, annotated in databases as a putative IMPDH, encodes a guanosine 5'-monophosphate reductase (GMPR), which recycles guanosine monophosphate to inosine monophosphate within the purine-salvage pathway and contains a cystathionine-β-synthase domain (CBS), which is essential for enzyme activity. GMPR activity is allosterically regulated by the ATP/GTP ratio in a pH-dependent manner. Bioinformatic analysis has indicated the presence of GMPRs containing CBS domains across the entire Actinobacteria phylum.
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Affiliation(s)
- Zdeněk Knejzlík
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Michal Doležal
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Klára Herkommerová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Kamila Clarova
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Martin Klíma
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Matteo Dedola
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Eva Zborníková
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Dominik Rejman
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
| | - Iva Pichová
- Institute of Organic Chemistry and Biochemistry of the Czech Academy of SciencesPragueCzech Republic
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Inosine triphosphate pyrophosphatase from Trypanosoma brucei cleanses cytosolic pools from deaminated nucleotides. Sci Rep 2022; 12:6408. [PMID: 35436992 PMCID: PMC9016069 DOI: 10.1038/s41598-022-10149-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 04/04/2022] [Indexed: 11/09/2022] Open
Abstract
AbstractInosine triphosphate pyrophosphatases (ITPases) are ubiquitous house-cleaning enzymes that specifically recognize deaminated purine nucleotides and catalyze their hydrolytic cleavage. In this work, we have characterized the Trypanosoma brucei ITPase ortholog (TbITPA). Recombinant TbITPA efficiently hydrolyzes (deoxy)ITP and XTP nucleotides into their respective monophosphate form. Immunolocalization analysis performed in bloodstream forms suggests that the primary role of TbITPA is the exclusion of deaminated purines from the cytosolic nucleoside triphosphate pools. Even though ITPA-knockout bloodstream parasites are viable, they are more sensitive to inhibition of IMP dehydrogenase with mycophenolic acid, likely due to an expansion of IMP, the ITP precursor. On the other hand, TbITPA can also hydrolyze the activated form of the antiviral ribavirin although in this case, the absence of ITPase activity in the cell confers protection against this nucleoside analog. This unexpected phenotype is dependant on purine availability and can be explained by the fact that ribavirin monophosphate, the reaction product generated by TbITPA, is a potent inhibitor of trypanosomal IMP dehydrogenase and GMP reductase. In summary, the present study constitutes the first report on a protozoan inosine triphosphate pyrophosphatase involved in the removal of harmful deaminated nucleotides from the cytosolic pool.
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Allosteric regulation accompanied by oligomeric state changes of Trypanosoma brucei GMP reductase through cystathionine-β-synthase domain. Nat Commun 2020; 11:1837. [PMID: 32296055 PMCID: PMC7160140 DOI: 10.1038/s41467-020-15611-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 03/19/2020] [Indexed: 11/09/2022] Open
Abstract
Guanosine 5'-monophosphate reductase (GMPR) is involved in the purine salvage pathway and is conserved throughout evolution. Nonetheless, the GMPR of Trypanosoma brucei (TbGMPR) includes a unique structure known as the cystathionine-β-synthase (CBS) domain, though the role of this domain is not fully understood. Here, we show that guanine and adenine nucleotides exert positive and negative effects, respectively, on TbGMPR activity by binding allosterically to the CBS domain. The present structural analyses revealed that TbGMPR forms an octamer that shows a transition between relaxed and twisted conformations in the absence and presence of guanine nucleotides, respectively, whereas the TbGMPR octamer dissociates into two tetramers when ATP is available instead of guanine nucleotides. These findings demonstrate that the CBS domain plays a key role in the allosteric regulation of TbGMPR by facilitating the transition of its oligomeric state depending on ligand nucleotide availability.
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Sarwono AEY, Suganuma K, Mitsuhashi S, Okada T, Musinguzi SP, Shigetomi K, Inoue N, Ubukata M. Identification and characterization of guanosine 5'-monophosphate reductase of Trypanosoma congolense as a drug target. Parasitol Int 2017; 66:537-544. [PMID: 28366788 DOI: 10.1016/j.parint.2017.03.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2016] [Revised: 02/17/2017] [Accepted: 03/27/2017] [Indexed: 10/19/2022]
Abstract
Trypanosoma congolense is one of the most prevalent pathogens which causes trypanosomosis in African animals, resulting in a significant economic loss. In its life cycle, T. congolense is incapable of synthesizing purine nucleotides via a de novo pathway, and thus relies on a salvage pathway to survive. In this study, we identified a gene from T. congolense, TcIL3000_5_1940, as a guanosine 5'-monophosphate reductase (GMPR), an enzyme that modulates the concentration of intracellular guanosine in the pathogen. The recombinant protein was expressed in Escherichia coli, and the gene product was enzymatically confirmed as a unique GMPR, designated as rTcGMPR. This enzyme was constitutively expressed in glycosomes at all of the parasite's developmental stages similar to other purine nucleotide metabolic enzymes. Mycophenolic acid (MPA) was found to inhibit rTcGMPR activity. Hence, it is a potential lead compound for the design of trypanocidal agents, specifically GMPR inhibitor.
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Affiliation(s)
- Albertus Eka Yudistira Sarwono
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Keisuke Suganuma
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan; Research Center for Global Agromedicine, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Shinya Mitsuhashi
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Tadashi Okada
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan; Division of Neurology, Respirology, Endocrinology and Metabolism, Department of Internal Medicine, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
| | - Simon Peter Musinguzi
- National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Kengo Shigetomi
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan
| | - Noboru Inoue
- Obihiro University of Agriculture and Veterinary Medicine, Inada, Obihiro, Hokkaido 080-8555, Japan
| | - Makoto Ubukata
- Division of Applied Bioscience, Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo, Hokkaido 060-8589, Japan.
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Boitz JM, Jardim A, Ullman B. GMP reductase and genetic uncoupling of adenylate and guanylate metabolism in Leishmania donovani parasites. Mol Biochem Parasitol 2016; 208:74-83. [PMID: 27343371 DOI: 10.1016/j.molbiopara.2016.06.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Revised: 06/20/2016] [Accepted: 06/21/2016] [Indexed: 11/26/2022]
Abstract
Purine acquisition is an essential nutritional process for Leishmania. Although purine salvage into adenylate nucleotides has been investigated in detail, little attention has been focused on the guanylate branch of the purine pathway. To characterize guanylate nucleotide metabolism in Leishmania and create a cell culture model in which the pathways for adenylate and guanylate nucleotide synthesis can be genetically uncoupled for functional studies in intact cells, we created and characterized null mutants of L. donovani that were deficient in either GMP reductase alone (Δgmpr) or in both GMP reductase and its paralog IMP dehydrogenase (Δgmpr/Δimpdh). Whereas wild type parasites were capable of utilizing virtually any purine nucleobase/nucleoside, the Δgmpr and Δgmpr/Δimpdh null lines exhibited highly restricted growth phenotypes. The Δgmpr single mutant could not grow in xanthine, guanine, or their corresponding nucleosides, while no purine on its own could support the growth of Δgmpr/Δimpdh cells. Permissive growth conditions for the Δgmpr/Δimpdh necessitated both xanthine, guanine, or the corresponding nucleosides, and additionally, a second purine that could serve as a source for adenylate nucleotide synthesis. Interestingly, GMPR, like its paralog IMPDH, is compartmentalized to the leishmanial glycosome, a process mediated by its COOH-terminal peroxisomal targeting signal. The restricted growth phenotypes displayed by the L. donovani Δgmpr and Δgmpr/Δimpdh null mutants confirms the importance of GMPR in the purine interconversion processes of this parasite.
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Affiliation(s)
- Jan M Boitz
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Mail Code L224, Portland, OR 97239, USA
| | - Armando Jardim
- Institute of Parasitology and Centre for Host-Parasite Interactions, Macdonald Campus of McGill University, 21 111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, H9X3V9, Canada
| | - Buddy Ullman
- Department of Biochemistry and Molecular Biology, Oregon Health & Science University, 3181 SW Sam Jackson Park Rd., Mail Code L224, Portland, OR 97239, USA.
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