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Tessi TM, Maurino VG, Shahriari M, Meissner E, Novak O, Pasternak T, Schumacher BS, Ditengou F, Li Z, Duerr J, Flubacher NS, Nautscher M, Williams A, Kazimierczak Z, Strnad M, Thumfart JO, Palme K, Desimone M, Teale WD. AZG1 is a cytokinin transporter that interacts with auxin transporter PIN1 and regulates the root stress response. THE NEW PHYTOLOGIST 2023; 238:1924-1941. [PMID: 36918499 DOI: 10.1111/nph.18879] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/29/2023] [Indexed: 05/04/2023]
Abstract
An environmentally responsive root system is crucial for plant growth and crop yield, especially in suboptimal soil conditions. This responsiveness enables the plant to exploit regions of high nutrient density while simultaneously minimizing abiotic stress. Despite the vital importance of root systems in regulating plant growth, significant gaps of knowledge exist in the mechanisms that regulate their architecture. Auxin defines both the frequency of lateral root (LR) initiation and the rate of LR outgrowth. Here, we describe a search for proteins that regulate root system architecture (RSA) by interacting directly with a key auxin transporter, PIN1. The native separation of Arabidopsis plasma membrane protein complexes identified several PIN1 co-purifying proteins. Among them, AZG1 was subsequently confirmed as a PIN1 interactor. Here, we show that, in Arabidopsis, AZG1 is a cytokinin (CK) import protein that co-localizes with and stabilizes PIN1, linking auxin and CK transport streams. AZG1 expression in LR primordia is sensitive to NaCl, and the frequency of LRs is AZG1-dependent under salt stress. This report therefore identifies a potential point for auxin:cytokinin crosstalk, which shapes RSA in response to NaCl.
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Affiliation(s)
- Tomás M Tessi
- Instituto Multidisciplinario de Biología Vegetal, Velez Sarsfield 249, 5000, Córdoba, Argentina
| | - Veronica G Maurino
- Molecular Plant Physiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany
| | - Mojgan Shahriari
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Esther Meissner
- Conservation Ecology, Department Biology, Philipps-Universität Marburg, Karl-von-Frisch-Straße 8, 35032, Marburg, Germany
| | - Ondrej Novak
- Laboratory of Growth Regulators, Institute of Experimental Botany ASCR and Palacky, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Taras Pasternak
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Benjamin S Schumacher
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, 72076, Tübingen, Germany
| | - Franck Ditengou
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Zenglin Li
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Jasmin Duerr
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Noemi S Flubacher
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Moritz Nautscher
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Alyssa Williams
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Zuzanna Kazimierczak
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
| | - Miroslav Strnad
- Laboratory of Growth Regulators, Institute of Experimental Botany ASCR and Palacky, Šlechtitelů 27, 783 71, Olomouc, Czech Republic
| | - Jörg-Oliver Thumfart
- Faculty of Medicine, Institute of Physiology II, University of Freiburg, Hermann-Herder-Strasse 7, 79104, Freiburg, Germany
- Labormedizinisches Zentrum Ostschweiz, Lagerstrasse 30, 9470, Buchs, SG, Switzerland
| | - Klaus Palme
- Molecular Plant Physiology, Institute of Cellular and Molecular Botany, University of Bonn, Kirschallee 1, 53115, Bonn, Germany
- Centre of Biological Systems Analysis, University of Freiburg, 79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104, Freiburg, Germany
| | - Marcelo Desimone
- Instituto Multidisciplinario de Biología Vegetal, Velez Sarsfield 249, 5000, Córdoba, Argentina
| | - William D Teale
- Institute of Biology II, University of Freiburg, Schänzlestrasse 1, 79104, Freiburg, Germany
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Vignesh P, Mahadevaiah C, Parimalan R, Valarmathi R, Dharshini S, Nisha S, Suresha GS, Swathi S, Mahadeva Swamy HK, Sreenivasa V, Mohanraj K, Hemaprabha G, Bakshi R, Appunu C. Comparative de novo transcriptome analysis identifies salinity stress responsive genes and metabolic pathways in sugarcane and its wild relative Erianthus arundinaceus [Retzius] Jeswiet. Sci Rep 2021; 11:24514. [PMID: 34972826 PMCID: PMC8720094 DOI: 10.1038/s41598-021-03735-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Accepted: 12/08/2021] [Indexed: 11/09/2022] Open
Abstract
Erianthus arundinaceus [Retzius] Jeswiet, a wild relative of sugarcane has a high biomass production potential and a reservoir of many genes for superior agronomic traits and tolerance to biotic and abiotic stresses. A comparative physiological, anatomical and root transcriptome analysis were carried out to identify the salt-responsive genes and metabolic pathways associated with salt-tolerant E. arundinaceus genotype IND99-907 and salinity-sensitive sugarcane genotype Co 97010. IND99-907 recorded growth of young leaves, higher proline content, higher relative water content, intact root anatomical structures and lower Na+/K+, Ca2+/K+ and Mg2+/K+ ratio as compared to the sugarcane genotype Co 97010. We have generated four de novo transcriptome assemblies between stressed and control root samples of IND99-907 and Co 97010. A total of 649 and 501 differentially expressed genes (FDR<0.01) were identified from the stressed and control libraries of IND99-907 and Co 97010 respectively. Genes and pathways related to early stress-responsive signal transduction, hormone signalling, cytoskeleton organization, cellular membrane stabilization, plasma membrane-bound calcium and proton transport, sodium extrusion, secondary metabolite biosynthesis, cellular transporters related to plasma membrane-bound trafficking, nucleobase transporter, clathrin-mediated endocytosis were highly enriched in IND99-907. Whereas in Co 97010, genes related to late stress-responsive signal transduction, electron transport system, senescence, protein degradation and programmed cell death, transport-related genes associated with cellular respiration and mitochondrial respiratory chain, vesicular trafficking, nitrate transporter and fewer secondary metabolite biosynthetic genes were highly enriched. A total of 27 pathways, 24 biological processes, three molecular functions and one cellular component were significantly enriched (FDR≤ 0.05) in IND99-907 as compared to 20 pathways, two biological processes without any significant molecular function and cellular components in Co 97010, indicates the unique and distinct expression pattern of genes and metabolic pathways in both genotypes. The genomic resources developed from this study is useful for sugarcane crop improvement through development of genic SSR markers and genetic engineering approaches.
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Affiliation(s)
- P Vignesh
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - C Mahadevaiah
- ICAR-Sugarcane Breeding Institute, Coimbatore, India.
| | - R Parimalan
- ICAR-National Bureau of Plant Genetic Resources, New Delhi, India
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, Australia
| | - R Valarmathi
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - S Dharshini
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - Singh Nisha
- ICAR-National Institute for Plant Biotechnology, New Delhi, India
- Institute for Genomic Diversity, Cornell University, Ithaca, NY, 14853, USA
| | - G S Suresha
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - S Swathi
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | | | - V Sreenivasa
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - K Mohanraj
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - G Hemaprabha
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - Ram Bakshi
- ICAR-Sugarcane Breeding Institute, Coimbatore, India
| | - C Appunu
- ICAR-Sugarcane Breeding Institute, Coimbatore, India.
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Holzhüter K, Geertsma ER. Uniport, Not Proton-Symport, in a Non-Mammalian SLC23 Transporter. J Mol Biol 2021; 434:167393. [PMID: 34896363 DOI: 10.1016/j.jmb.2021.167393] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 11/17/2021] [Accepted: 12/01/2021] [Indexed: 10/25/2022]
Abstract
SLC23 family members are transporters of either nucleobases or ascorbate. While the mammalian SLC23 ascorbate transporters are sodium-coupled, the non-mammalian nucleobase transporters have been proposed, but not formally shown, to be proton-coupled symporters. This assignment is exclusively based on in vivo transport assays using protonophores. Here, by establishing the first in vitro transport assay for this protein family, we demonstrate that a representative member of the SLC23 nucleobase transporters operates as a uniporter instead. We explain these conflicting assignments by identifying a critical role of uracil phosphoribosyltransferase, the enzyme converting uracil to UMP, in driving uracil uptake in vivo. Detailed characterization of uracil phosphoribosyltransferase reveals that the sharp reduction of uracil uptake in whole cells in presence of protonophores is caused by acidification-induced enzyme inactivation. The SLC23 family therefore consists of both uniporters and symporters in line with the structurally related SLC4 and SLC26 families that have previously been demonstrated to accommodate both transport modes as well.
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Affiliation(s)
- Katharina Holzhüter
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany
| | - Eric R Geertsma
- Institute of Biochemistry, Biocenter, Goethe University Frankfurt, Max-von-Laue Str. 9, D-60438 Frankfurt am Main, Germany; Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, D-01307 Dresden, Germany.
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Tatsaki E, Anagnostopoulou E, Zantza I, Lazou P, Mikros E, Frillingos S. Identification of New Specificity Determinants in Bacterial Purine Nucleobase Transporters based on an Ancestral Sequence Reconstruction Approach. J Mol Biol 2021; 433:167329. [PMID: 34710398 DOI: 10.1016/j.jmb.2021.167329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 10/05/2021] [Accepted: 10/19/2021] [Indexed: 11/28/2022]
Abstract
The relation of sequence with specificity in membrane transporters is challenging to explore. Most relevant studies until now rely on comparisons of present-day homologs. In this work, we study a set of closely related transporters by employing an evolutionary, ancestral-reconstruction approach and reveal unexpected new specificity determinants. We analyze a monophyletic group represented by the xanthine-specific XanQ of Escherichia coli in the Nucleobase-Ascorbate Transporter/Nucleobase-Cation Symporter-2 (NAT/NCS2) family. We reconstructed AncXanQ, the putative common ancestor of this clade, expressed it in E. coli K-12, and found that, in contrast to XanQ, it encodes a high-affinity permease for both xanthine and guanine, which also recognizes adenine, hypoxanthine, and a range of analogs. AncXanQ conserves all binding-site residues of XanQ and differs substantially in only five intramembrane residues outside the binding site. We subjected both homologs to rationally designed mutagenesis and present evidence that these five residues are linked with the specificity change. In particular, we reveal Ser377 of XanQ (Gly in AncXanQ) as a major determinant. Replacement of this Ser with Gly enlarges the specificity of XanQ towards an AncXanQ-phenotype. The ortholog from Neisseria meningitidis retaining Gly at this position is also a xanthine/guanine transporter with extended substrate profile like AncXanQ. Molecular Dynamics shows that the S377G replacement tilts transmembrane helix 12 resulting in rearrangement of Phe376 relative to Phe94 in the XanQ binding pocket. This effect may rationalize the enlarged specificity. On the other hand, the specificity effect of S377G can be masked by G27S or other mutations through epistatic interactions.
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Affiliation(s)
- Ekaterini Tatsaki
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Eleni Anagnostopoulou
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece. https://twitter.com/EleniAnagn
| | - Iliana Zantza
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Panayiota Lazou
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Emmanuel Mikros
- Division of Pharmaceutical Chemistry, Department of Pharmacy, School of Health Sciences, National and Kapodistrian University of Athens, Athens, Greece
| | - Stathis Frillingos
- Laboratory of Biological Chemistry, Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece; Institute of Biosciences, University Research Center of Ioannina, Ioannina, Greece.
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5
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Context-dependent Cryptic Roles of Specific Residues in Substrate Selectivity of the UapA Purine Transporter. J Mol Biol 2021; 433:166814. [PMID: 33497644 DOI: 10.1016/j.jmb.2021.166814] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 12/29/2020] [Accepted: 01/04/2021] [Indexed: 12/22/2022]
Abstract
Members of the ubiquitous Nucleobase Ascorbate Transporter (NAT) family are H+ or Na+ symporters specific for the cellular uptake of either purines and pyrimidines or L-ascorbic acid. Despite the fact that several bacterial and fungal members have been extensively characterised at a genetic, biochemical or cellular level, and crystal structures of NAT members from Escherichia coli and Aspergillus nidulans have been determined pointing to a mechanism of transport, we have little insight on how substrate selectivity is determined. Here, we present systematic mutational analyses, rational combination of mutations, and novel genetic screens that reveal cryptic context-dependent roles of partially conserved residues in the so-called NAT signature motif in determining the specificity of the UapA transporter of A. nidulans. We show that specific NAT signature motif substitutions, alone and in combinations with each other or with distant mutations in residues known to affect substrate selectivity, lead to novel UapA versions possessing variable transport capacities and specificities for nucleobases. In particular, we show that a UapA version including the quadruple mutation T405S/F406Y/A407S/Q408E in the NAT signature motif (UapA-SYSE) becomes incapable of purine transport, but gains a novel pyrimidine-related profile, which can be further altered to a more promiscuous purine/pyrimidine profile when combined with replacements at distantly located residues, especially at F528. Our results reveal that UapA specificity is genetically highly modifiable and allow us to speculate on how the elevator-type mechanism of transport might account for this flexibility.
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6
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Sun T, Pei T, Yang L, Zhang Z, Li M, Liu Y, Ma F, Liu C. Exogenous application of xanthine and uric acid and nucleobase-ascorbate transporter MdNAT7 expression regulate salinity tolerance in apple. BMC PLANT BIOLOGY 2021; 21:52. [PMID: 33468049 PMCID: PMC7816448 DOI: 10.1186/s12870-021-02831-y] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2020] [Accepted: 01/07/2021] [Indexed: 05/05/2023]
Abstract
BACKGROUND Soil salinity is a critical threat to global agriculture. In plants, the accumulation of xanthine activates xanthine dehydrogenase (XDH), which catalyses the oxidation/conversion of xanthine to uric acid to remove excess reactive oxygen species (ROS). The nucleobase-ascorbate transporter (NAT) family is also known as the nucleobase-cation symporter (NCS) or AzgA-like family. NAT is known to transport xanthine and uric acid in plants. The expression of MdNAT is influenced by salinity stress in apple. RESULTS In this study, we discovered that exogenous application of xanthine and uric acid enhanced the resistance of apple plants to salinity stress. In addition, MdNAT7 overexpression transgenic apple plants showed enhanced xanthine and uric acid concentrations and improved tolerance to salinity stress compared with nontransgenic plants, while opposite phenotypes were observed for MdNAT7 RNAi plants. These differences were probably due to the enhancement or impairment of ROS scavenging and ion homeostasis abilities. CONCLUSION Our results demonstrate that xanthine and uric acid have potential uses in salt stress alleviation, and MdNAT7 can be utilized as a candidate gene to engineer resistance to salt stress in plants.
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Affiliation(s)
- Tingting Sun
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
- Beijing Academy of Forestry and Pomology Sciences, Beijing Engineering Research Center for Deciduous Fruit Trees, Key Laboratory of Biology and Genetic Improvement of Horticultural Crops (North China), Ministry of Agriculture and Rural Affairs, Beijing, 100093, People's Republic of China
| | - Tingting Pei
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Lulu Yang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Zhijun Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Mingjun Li
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Yuerong Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China
| | - Fengwang Ma
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
| | - Changhai Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas/Shaanxi Key Laboratory of Apple, College of Horticulture, Northwest A&F University, Yangling, 712100, Shaanxi, China.
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Tessi TM, Brumm S, Winklbauer E, Schumacher B, Pettinari G, Lescano I, González CA, Wanke D, Maurino VG, Harter K, Desimone M. Arabidopsis AZG2 transports cytokinins in vivo and regulates lateral root emergence. THE NEW PHYTOLOGIST 2021; 229:979-993. [PMID: 33070379 DOI: 10.1111/nph.16943] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/23/2020] [Indexed: 05/06/2023]
Abstract
Cytokinin and auxin are key regulators of plant growth and development. During the last decade transport mechanisms have turned out to be the key for the control of local and long-distance hormone distributions. In contrast with auxin, cytokinin transport is poorly understood. Here, we show that Arabidopsis thaliana AZG2, a member of the AZG purine transporter family, acts as cytokinin transporter involved in root system architecture determination. Even though purines are substrates for both AZG1 and AZG2, we found distinct transport mechanisms. The expression of AZG2 is restricted to a small group of cells surrounding the lateral root (LR) primordia and induced by auxins. Compared to the wild-type (WT), mutants carrying loss-of-function alleles of AZG2 have higher LR density, suggesting that AZG2 is part of a regulatory pathway in LR emergence. Moreover, azg2 is partially insensitive to exogenous cytokinin, which is consistent with the observation that the cytokinin reporter TCSnpro :GFP showed lower fluorescence signal in the roots of azg2 compared to the WT. These results indicate a defective cytokinin signalling pathway in the region of LR primordia. The integration of AZG2 subcellular localization and cytokinin transport capacity data allowed us to propose a local cytokinin : auxin signalling model for the regulation of LR emergence.
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Affiliation(s)
- Tomás M Tessi
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Av. Vélez Sarsfield 299, Córdoba, 5000, Argentina
| | - Sabine Brumm
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, Tübingen, 72076, Germany
| | - Eva Winklbauer
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, Tübingen, 72076, Germany
| | - Benjamin Schumacher
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, Tübingen, 72076, Germany
| | - Georgina Pettinari
- Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, Córdoba, 5000, Argentina
| | - Ignacio Lescano
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Av. Vélez Sarsfield 299, Córdoba, 5000, Argentina
| | - Claudio A González
- Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, Córdoba, 5000, Argentina
| | - Dierk Wanke
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, Tübingen, 72076, Germany
| | - Verónica G Maurino
- Institut für Molekulare Physiologie und Biotechnologie der Pflanzen, Abteilung Molekulare Pflanzenphysiologie, Universität Bonn, Kirschallee 1, Bonn, 53115, Germany
| | - Klaus Harter
- Zentrum für Molekularbiologie der Pflanzen, Universität Tübingen, Auf der Morgenstelle 1, Tübingen, 72076, Germany
| | - Marcelo Desimone
- Instituto Multidisciplinario de Biología Vegetal (IMBIV), CONICET, Av. Vélez Sarsfield 299, Córdoba, 5000, Argentina
- Facultad de Ciencias Exactas Físicas y Naturales, Universidad Nacional de Córdoba, Av. Vélez Sarsfield 299, Córdoba, 5000, Argentina
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Nguyen J, Schein J, Hunt K, Tippmann-Feightner J, Rapp M, Stoffer-Bittner A, Nalam V, Funk A, Schultes N, Mourad G. The Nicotiana sylvestris nucleobase cation symporter 1 retains a dicot solute specificity profile. ACTA ACUST UNITED AC 2020. [DOI: 10.1016/j.plgene.2020.100226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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9
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Campagnaro GD, de Koning HP. Purine and pyrimidine transporters of pathogenic protozoa - conduits for therapeutic agents. Med Res Rev 2020; 40:1679-1714. [PMID: 32144812 DOI: 10.1002/med.21667] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 02/12/2020] [Accepted: 02/18/2020] [Indexed: 02/06/2023]
Abstract
Purines and pyrimidines are essential nutrients for any cell. Most organisms are able to synthesize their own purines and pyrimidines, but this ability was lost in protozoans that adapted to parasitism, leading to a great diversification in transporter activities in these organisms, especially for the acquisition of amino acids and nucleosides from their hosts throughout their life cycles. Many of these transporters have been shown to have sufficiently different substrate affinities from mammalian transporters, making them good carriers for therapeutic agents. In this review, we summarize the knowledge obtained on purine and pyrimidine activities identified in protozoan parasites to date and discuss their importance for the survival of these parasites and as drug carriers, as well as the perspectives of developments in the field.
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Affiliation(s)
- Gustavo D Campagnaro
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
| | - Harry P de Koning
- Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, 120 University Place, Glasgow, UK
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Scheerer U, Trube N, Netzer F, Rennenberg H, Herschbach C. ATP as Phosphorus and Nitrogen Source for Nutrient Uptake by Fagus sylvatica and Populus x canescens Roots. FRONTIERS IN PLANT SCIENCE 2019; 10:378. [PMID: 31019519 PMCID: PMC6458296 DOI: 10.3389/fpls.2019.00378] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 03/12/2019] [Indexed: 05/08/2023]
Abstract
The present study elucidated whether roots of temperate forest trees can take up organic phosphorus in the form of ATP. Detached non-mycorrhizal roots of beech (Fagus sylvatica) and gray poplar (Populus x canescens) were exposed under controlled conditions to 33P-ATP and/or 13C/15N labeled ATP in the presence and absence of the acid phosphatase inhibitor MoO4 2-. Accumulation of the respective label in the roots was used to calculate 33P, 13C and 15N uptake rates in ATP equivalents for comparison reason. The present data shown that a significant part of ATP was cleaved outside the roots before phosphate (Pi) was taken up. Furthermore, nucleotide uptake seems more reasonable after cleavage of at least one Pi unit as ADP, AMP and/or as the nucleoside adenosine. Similar results were obtained when still attached mycorrhizal roots of adult beech trees and their natural regeneration of two forest stands were exposed to ATP in the presence or absence of MoO4 2-. Cleavage of Pi from ATP by enzymes commonly present in the rhizosphere, such as extracellular acid phosphatases, ecto-apyrase and/or nucleotidases, prior ADP/AMP/adenosine uptake is highly probable but depended on the soil type and the pH of the soil solution. Although uptake of ATP/ADP/AMP cannot be excluded, uptake of the nucleoside adenosine without breakdown into its constituents ribose and adenine is highly evident. Based on the 33P, 13C, and 15N uptake rates calculated as equivalents of ATP the 'pro and contra' for the uptake of nucleotides and nucleosides is discussed. Short Summary Roots take up phosphorus from ATP as Pi after cleavage but might also take up ADP and/or AMP by yet unknown nucleotide transporter(s) because at least the nucleoside adenosine as N source is taken up without cleavage into its constituents ribose and adenine.
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Affiliation(s)
- Ursula Scheerer
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Niclas Trube
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Florian Netzer
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
- Chair of Ecosystem Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Heinz Rennenberg
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
| | - Cornelia Herschbach
- Chair of Tree Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
- Chair of Ecosystem Physiology, Institute of Forest Sciences, Albert-Ludwigs-University Freiburg, Freiburg, Germany
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Stoffer-Bittner AJ, Alexander CR, Dingman DW, Mourad GS, Schultes NP. Functional characterization of the uracil transporter from honeybee pathogen Paenibacillus larvae. Microb Pathog 2018; 124:305-310. [DOI: 10.1016/j.micpath.2018.08.059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 08/25/2018] [Indexed: 11/30/2022]
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12
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Stoffer‐Bittner AJ, Alexander CR, Dingman DW, Mourad GS, Schultes NP. The solute transport and binding profile of a novel nucleobase cation symporter 2 from the honeybee pathogen Paenibacillus larvae. FEBS Open Bio 2018; 8:1322-1331. [PMID: 30087835 PMCID: PMC6070649 DOI: 10.1002/2211-5463.12488] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 06/22/2018] [Accepted: 06/24/2018] [Indexed: 11/29/2022] Open
Abstract
Here, we report that a novel nucleobase cation symporter 2 encoded in the genome of the honeybee bacterial pathogen Paenibacillus larvae reveals high levels of amino acid sequence similarity to the Escherichia coli and Bacillus subtilis uric acid and xanthine transporters. This transporter is named P. larvae uric acid permease-like protein (PlUacP). Even though PlUacP displays overall amino acid sequence similarities, has common secondary structures, and shares functional motifs and functionally important amino acids with E. coli xanthine and uric acid transporters, these commonalities are insufficient to assign transport function to PlUacP. The solute transport and binding profile of PlUacP was determined by radiolabeled uptake experiments via heterologous expression in nucleobase transporter-deficient Saccharomyces cerevisiae strains. PlUacP transports the purines adenine and guanine and the pyrimidine uracil. Hypoxanthine, xanthine, and cytosine are not transported by PlUacP, but, along with uric acid, bind in a competitive manner. PlUacP has strong affinity for adenine Km 7.04 ± 0.18 μm, and as with other bacterial and plant NCS2 proteins, PlUacP function is inhibited by the proton disruptor carbonyl cyanide m-chlorophenylhydrazone. The solute transport and binding profile identifies PlUacP as a novel nucleobase transporter.
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Affiliation(s)
| | | | - Douglas W. Dingman
- Department of EntomologyThe Connecticut Agricultural Experiment StationNew HavenCTUSA
| | - George S. Mourad
- Department of BiologyIndiana University‐Purdue University Fort WayneINUSA
| | - Neil P. Schultes
- Department of Plant Pathology & EcologyThe Connecticut Agricultural Experiment StationNew HavenCTUSA
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13
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Chai W, Peng X, Liu B, Wang J, Zhu Z, Liu Y, Zhao K, Cheng B, Si W, Jiang H. Comparative Genomics, Whole-Genome Re-sequencing and Expression Profile Analysis of Nucleobase:Cation Symporter 2 ( NCS2) Genes in Maize. FRONTIERS IN PLANT SCIENCE 2018; 9:856. [PMID: 30002663 PMCID: PMC6031955 DOI: 10.3389/fpls.2018.00856] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 06/01/2018] [Indexed: 06/08/2023]
Abstract
Nucleobase:cation symporter 2 (NCS2) proteins are important for the transport of free nucleobases, participating in diverse plant growth and developmental processes, as well as response to abiotic stress. To date, a comprehensive analysis of the NCS2 gene family has not been performed in maize. In this study, we conducted a comparative genomics analysis of NCS2 genes in 28 plant species, ranging from aquatic algae to land plants, concentrating mainly on maize. Gene duplication events contributed to the expansion of NCS2 genes from lower aquatic plants to higher angiosperms, and whole-genome/segmental and single-gene duplication events were responsible for the expansion of the maize NCS2 gene family. Phylogenetic construction showed three NCS2 subfamilies, I, II, and III. According to homology-based relationships, members of subfamily I are NCS2/AzgA-like genes, whereas those in subfamilies II and III are NCS2/NATs. Moreover, subfamily I exhibited ancient origins. A motif compositional analysis showed that one symbolic motif (motif 4) of the NCS2/NAT genes was absent in subfamily I. In maize, three NCS2/AzgA-like and 21 NCS2/NAT genes were identified, and purifying selection influenced the duplication of maize NCS2 genes. Additionally, a population genetic analysis of NCS2 genes revealed that ZmNCS2-21 showed the greatest diversity between the 78 inbred and 22 wild surveyed maize populations. An expression profile analysis using transcriptome data and quantitative real-time PCR revealed that NCS2 genes in maize are involved in diverse developmental processes and responses to abiotic stresses, including abscisic acid, salt (NaCl), polyethylene glycol, and low (4°C) and high (42°C) temperatures. ZmNCS2 genes with relatively close relationships had similar expression patterns, strongly indicating functional redundancy. Finally, ZmNCS2-16 and ZmNCS2-23 localize in the plasma membrane, which confirmed their predicted membrane structures. These results provide a foundation for future studies regarding the functions of ZmNCS2 proteins, particularly those with potentially important roles in plant responses to abiotic stresses.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Weina Si
- National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, China
| | - Haiyang Jiang
- National Engineering Laboratory of Crop Stress Resistance Breeding, School of Life Sciences, Anhui Agricultural University, Hefei, China
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14
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Kourkoulou A, Pittis AA, Diallinas G. Evolution of substrate specificity in the Nucleobase-Ascorbate Transporter (NAT) protein family. MICROBIAL CELL 2018; 5:280-292. [PMID: 29850465 PMCID: PMC5972032 DOI: 10.15698/mic2018.06.636] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
L-ascorbic acid (vitamin C) is an essential metabolite in animals and plants due to its role as an enzyme co-factor and antioxidant activity. In most eukaryotic organisms, L-ascorbate is biosynthesized enzymatically, but in several major groups, including the primate suborder Haplorhini, this ability is lost due to gene truncations in the gene coding for L-gulonolactone oxidase. Specific ascorbate transporters (SVCTs) have been characterized only in mammals and shown to be essential for life. These belong to an extensively studied transporter family, called Nucleobase-Ascorbate Transporters (NAT). The prototypic member of this family, and one of the most extensively studied eukaryotic transporters, is UapA, a uric acid-xanthine/H+ symporter in the fungus Aspergillus nidulans. Here, we investigate molecular aspects of NAT substrate specificity and address the evolution of ascorbate transporters apparently from ancestral nucleobase transporters. We present a phylogenetic analysis, identifying a distinct NAT clade that includes all known L-ascorbate transporters. This clade includes homologues only from vertebrates, and has no members in non-vertebrate or microbial eukaryotes, plants or prokaryotes. Additionally, we identify within the substrate-binding site of NATs a differentially conserved motif, which we propose is critical for nucleobase versus ascorbate recognition. This conclusion is supported by the amino acid composition of this motif in distinct phylogenetic clades and mutational analysis in the UapA transporter. Together with evidence obtained herein that UapA can recognize with extremely low affinity L-ascorbate, our results support that ascorbate-specific NATs evolved by optimization of a sub-function of ancestral nucleobase transporters.
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Affiliation(s)
- Anezia Kourkoulou
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens 15784, Greece
| | | | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, Athens 15784, Greece
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15
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Botou M, Lazou P, Papakostas K, Lambrinidis G, Evangelidis T, Mikros E, Frillingos S. Insight on specificity of uracil permeases of the NAT/NCS2 family from analysis of the transporter encoded in the pyrimidine utilization operon ofEscherichia coli. Mol Microbiol 2018; 108:204-219. [DOI: 10.1111/mmi.13931] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2018] [Indexed: 02/06/2023]
Affiliation(s)
- Maria Botou
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences; University of Ioannina; Ioannina Greece
| | - Panayiota Lazou
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences; University of Ioannina; Ioannina Greece
| | - Konstantinos Papakostas
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences; University of Ioannina; Ioannina Greece
| | - George Lambrinidis
- Division of Pharmaceutical Chemistry Department of Pharmacy School of Health Sciences; National and Kapodistrian University of Athens; Athens Greece
| | - Thomas Evangelidis
- Division of Pharmaceutical Chemistry Department of Pharmacy School of Health Sciences; National and Kapodistrian University of Athens; Athens Greece
| | - Emmanuel Mikros
- Division of Pharmaceutical Chemistry Department of Pharmacy School of Health Sciences; National and Kapodistrian University of Athens; Athens Greece
| | - Stathis Frillingos
- Laboratory of Biological Chemistry Department of Medicine School of Health Sciences; University of Ioannina; Ioannina Greece
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16
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Ashihara H, Stasolla C, Fujimura T, Crozier A. Purine salvage in plants. PHYTOCHEMISTRY 2018; 147:89-124. [PMID: 29306799 DOI: 10.1016/j.phytochem.2017.12.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 12/10/2017] [Accepted: 12/14/2017] [Indexed: 05/04/2023]
Abstract
Purine bases and nucleosides are produced by turnover of nucleotides and nucleic acids as well as from some cellular metabolic pathways. Adenosine released from the S-adenosyl-L-methionine cycle is linked to many methyltransferase reactions, such as the biosynthesis of caffeine and glycine betaine. Adenine is produced by the methionine cycles, which is related to other biosynthesis pathways, such those for the production of ethylene, nicotianamine and polyamines. These purine compounds are recycled for nucleotide biosynthesis by so-called "salvage pathways". However, the salvage pathways are not merely supplementary routes for nucleotide biosynthesis, but have essential functions in many plant processes. In plants, the major salvage enzymes are adenine phosphoribosyltransferase (EC 2.4.2.7) and adenosine kinase (EC 2.7.1.20). AMP produced by these enzymes is converted to ATP and utilised as an energy source as well as for nucleic acid synthesis. Hypoxanthine, guanine, inosine and guanosine are salvaged to IMP and GMP by hypoxanthine/guanine phosphoribosyltransferase (EC 2.4.2.8) and inosine/guanosine kinase (EC 2.7.1.73). In contrast to de novo purine nucleotide biosynthesis, synthesis by the salvage pathways is extremely favourable, energetically, for cells. In addition, operation of the salvage pathway reduces the intracellular levels of purine bases and nucleosides which inhibit other metabolic reactions. The purine salvage enzymes also catalyse the respective formation of cytokinin ribotides, from cytokinin bases, and cytokinin ribosides. Since cytokinin bases are the active form of cytokinin hormones, these enzymes act to maintain homeostasis of cellular cytokinin bioactivity. This article summarises current knowledge of purine salvage pathways and their possible function in plants and purine salvage activities associated with various physiological phenomena are reviewed.
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Affiliation(s)
- Hiroshi Ashihara
- Department of Biology, Ochanomizu University, Bunkyo-ku, Tokyo, 112-8610, Japan.
| | - Claudio Stasolla
- Department of Plant Science, University of Manitoba, Winnipeg, R3T 2N2, Canada
| | - Tatsuhito Fujimura
- Faculty of Life and Environmental Sciences, University of Tsukuba, Tsukuba, 305-8572, Japan
| | - Alan Crozier
- Department of Nutrition, University of California, Davis, CA, 95616-5270, USA
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17
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Alexander CR, Dingman DW, Schultes NP, Mourad GS. The solute transport profile of two Aza-guanine transporters from the Honey bee pathogen Paenibacillus larvae. FEMS Microbiol Lett 2018; 365:4828326. [DOI: 10.1093/femsle/fny018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 01/26/2018] [Indexed: 01/05/2023] Open
Affiliation(s)
- Candace R Alexander
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
| | - Douglas W Dingman
- Department of Entomology, The Connecticut Agricultural Experiment Station, 123 Huntington St, New Haven, CT 06511, USA
| | - Neil P Schultes
- Department of Plant Pathology & Ecology, The Connecticut Agricultural Experiment Station, 123 Huntington St, New Haven, CT 06511, USA
| | - George S Mourad
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
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18
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Daumann M, Golfier P, Knüppel N, Hahn M, Möhlmann T. Botrytis cinerea can import and utilize nucleosides in salvage and catabolism and BcENT functions as high affinity nucleoside transporter. Fungal Biol 2016; 120:904-916. [PMID: 27521624 DOI: 10.1016/j.funbio.2016.05.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 04/13/2016] [Accepted: 05/31/2016] [Indexed: 10/21/2022]
Abstract
Nucleotide de novo synthesis is an essential pathway in nearly all organisms. Transport processes as well as salvage and catabolism of nucleotides and pathway intermediates are required to balance nucleotide pools. We have analysed the genome of the fungal plant pathogen Botrytis cinerea for genes involved in nucleotide metabolism and found a complete set of genes necessary for purine and pyrimidine uptake and salvage based on homology of the gene products to corresponding proteins from Aspergillus nidulans. Candidate genes required for a complete purine catabolic sequence were identified in addition. These analyses were complemented by growth tests showing functional transport and salvage activity for pyrimidines. Growth of B. cinerea mycelium in nitrogen free medium could be restored by addition of purines, indicating the presence of a functional purine catabolism, whereas pyrimidines did not support growth. Bcin07g05490 (BcENT) was identified as sole member of the equilibrative nucleoside transporter (ENT) family. The protein synthesized in Saccharomyces cerevisiae revealed high affinity transport of adenosine (KM = 6.81 μM) and uridine (KM=9.04 μM). Furthermore, a BcENT knockout mutant was generated and tested in a range of growth and infection assays. These results provide detailed insight in the use of externally supplied nucleobases and nucleosides by B. cinerea.
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Affiliation(s)
- Manuel Daumann
- Pflanzenphysiologie, Fachbereich Biologie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany
| | - Philippe Golfier
- Pflanzenphysiologie, Fachbereich Biologie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany
| | - Nathalie Knüppel
- Phytopathologie, Fachbereich Biologie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany
| | - Matthias Hahn
- Phytopathologie, Fachbereich Biologie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany
| | - Torsten Möhlmann
- Pflanzenphysiologie, Fachbereich Biologie, Technische Universität Kaiserslautern, Erwin-Schrödinger-Straße, D-67663 Kaiserslautern, Germany.
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19
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Rapp M, Schein J, Hunt KA, Nalam V, Mourad GS, Schultes NP. The solute specificity profiles of nucleobase cation symporter 1 (NCS1) from Zea mays and Setaria viridis illustrate functional flexibility. PROTOPLASMA 2016; 253:611-23. [PMID: 26022088 DOI: 10.1007/s00709-015-0838-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 05/17/2015] [Indexed: 05/07/2023]
Abstract
The solute specificity profiles (transport and binding) for the nucleobase cation symporter 1 (NCS1) proteins, from the closely related C4 grasses Zea mays and Setaria viridis, differ from that of Arabidopsis thaliana and Chlamydomonas reinhardtii NCS1. Solute specificity profiles for NCS1 from Z. mays (ZmNCS1) and S. viridis (SvNCS1) were determined through heterologous complementation studies in NCS1-deficient Saccharomyces cerevisiae strains. The four Viridiplantae NCS1 proteins transport the purines adenine and guanine, but unlike the dicot and algal NCS1, grass NCS1 proteins fail to transport the pyrimidine uracil. Despite the high level of amino acid sequence similarity, ZmNCS1 and SvNCS1 display distinct solute transport and recognition profiles. SvNCS1 transports adenine, guanine, hypoxanthine, cytosine, and allantoin and competitively binds xanthine and uric acid. ZmNCS1 transports adenine, guanine, and cytosine and competitively binds, 5-fluorocytosine, hypoxanthine, xanthine, and uric acid. The differences in grass NCS1 profiles are due to a limited number of amino acid alterations. These amino acid residues do not correspond to amino acids essential for overall solute and cation binding or solute transport, as previously identified in bacterial and fungal NCS1, but rather may represent residues involved in subtle solute discrimination. The data presented here reveal that within Viridiplantae, NCS1 proteins transport a broad range of nucleobase compounds and that the solute specificity profile varies with species.
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Affiliation(s)
- Micah Rapp
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805, USA
| | - Jessica Schein
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805, USA
| | - Kevin A Hunt
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805, USA
| | - Vamsi Nalam
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805, USA
| | - George S Mourad
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN, 46805, USA
| | - Neil P Schultes
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, 123 Huntington St, New Haven, CT, 06511, USA.
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20
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Minton JA, Rapp M, Stoffer AJ, Schultes NP, Mourad GS. Heterologous complementation studies reveal the solute transport profiles of a two-member nucleobase cation symporter 1 (NCS1) family in Physcomitrella patens. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2016; 100:12-17. [PMID: 26773540 DOI: 10.1016/j.plaphy.2015.12.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2015] [Revised: 12/22/2015] [Accepted: 12/23/2015] [Indexed: 06/05/2023]
Abstract
As part of an evolution-function analysis, two nucleobase cation symporter 1 (NCS1) from the moss Physcomitrella patens (PpNCS1A and PpNCS1B) are examined--the first such analysis of nucleobase transporters from early land plants. The solute specificity profiles for the moss NCS1 were determined through heterologous expression, growth and radiolabeled uptake experiments in NCS1-deficient Saccharomyces cerevisiae. Both PpNCS1A and 1B, share the same profiles as high affinity transporters of adenine and transport uracil, guanine, 8-azaguanine, 8-azaadenine, cytosine, 5-fluorocytosine, hypoxanthine, and xanthine. Despite sharing the same solute specificity profile, PpNCS1A and PpNCS1B move nucleobase compounds with different efficiencies. The broad nucleobase transport profile of PpNCS1A and 1B differs from the recently-characterized Viridiplantae NCS1 in breadth, revealing a flexibility in solute interactions with NCS1 across plant evolution.
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Affiliation(s)
- Janet A Minton
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
| | - Micah Rapp
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
| | - Amanda J Stoffer
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA
| | - Neil P Schultes
- Department of Plant Pathology and Ecology, The Connecticut Agricultural Experiment Station, 123 Huntington St, New Haven, CT 06511, USA
| | - George S Mourad
- Department of Biology, Indiana University-Purdue University Fort Wayne, 2101 East Coliseum Blvd., Fort Wayne, IN 46805, USA.
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Daumann M, Fischer M, Niopek-Witz S, Girke C, Möhlmann T. Apoplastic Nucleoside Accumulation in Arabidopsis Leads to Reduced Photosynthetic Performance and Increased Susceptibility Against Botrytis cinerea. FRONTIERS IN PLANT SCIENCE 2015; 6:1158. [PMID: 26779190 PMCID: PMC4688390 DOI: 10.3389/fpls.2015.01158] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 12/07/2015] [Indexed: 05/15/2023]
Abstract
Interactions between plant and pathogen often occur in the extracellular space and especially nucleotides like ATP and NAD have been identified as key players in this scenario. Arabidopsis mutants accumulating nucleosides in the extracellular space were generated and studied with respect to susceptibility against Botrytis cinerea infection and general plant fitness determined as photosynthetic performance. The mutants used are deficient in the main nucleoside uptake system ENT3 and the extracellular nucleoside hydrolase NSH3. When grown on soil but not in hydroponic culture, these plants markedly accumulate adenosine and uridine in leaves. This nucleoside accumulation was accompanied by reduced photosystem II efficiency and altered expression of photosynthesis related genes. Moreover, a higher susceptibility toward Botrytis cinerea infection and a reduced induction of pathogen related genes PR1 and WRKY33 was observed. All these effects did not occur in hydroponically grown plants substantiating a contribution of extracellular nucleosides to these effects. Whether reduced general plant fitness, altered pathogen response capability or more direct interactions with the pathogen are responsible for these observations is discussed.
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22
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Girke C, Daumann M, Niopek-Witz S, Möhlmann T. Nucleobase and nucleoside transport and integration into plant metabolism. FRONTIERS IN PLANT SCIENCE 2014; 5:443. [PMID: 25250038 PMCID: PMC4158802 DOI: 10.3389/fpls.2014.00443] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 08/18/2014] [Indexed: 05/18/2023]
Abstract
Nucleotide metabolism is an essential process in all living organisms. Besides newly synthesized nucleotides, the recycling (salvage) of partially degraded nucleotides, i.e., nucleosides and nucleobases serves to keep the homeostasis of the nucleotide pool. Both types of metabolites are substrates of at least six families of transport proteins in Arabidopsis thaliana (Arabidopsis) with a total of 49 members. In the last years several members of such transport proteins have been analyzed allowing to present a more detailed picture of nucleoside and nucleobase transport and the physiological function of these processes. Besides functioning in nucleotide metabolism it turned out that individual members of the before named transporters exhibit the capacity to transport a wide range of different substrates including vitamins and phytohormones. The aim of this review is to summarize the current knowledge on nucleobase and nucleoside transport processes in plants and integrate this into nucleotide metabolism in general. Thereby, we will focus on those proteins which have been characterized at the biochemical level.
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Affiliation(s)
| | | | | | - Torsten Möhlmann
- *Correspondence: Torsten Möhlmann, Pflanzenphysiologie, Universität Kaiserslautern, Erwin-Schrödinger-Str., Postfach 3049, D-67653 Kaiserslautern, Germany e-mail:
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