1
|
López-Gómez P, Buezo J, Urra M, Cornejo A, Esteban R, Fernández de Los Reyes J, Urarte E, Rodríguez-Dobreva E, Chamizo-Ampudia A, Eguaras A, Wolf S, Marino D, Martínez-Merino V, Moran JF. A new oxidative pathway of nitric oxide production from oximes in plants. Mol Plant 2024; 17:178-198. [PMID: 38102832 DOI: 10.1016/j.molp.2023.12.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 09/06/2023] [Accepted: 12/12/2023] [Indexed: 12/17/2023]
Abstract
Nitric oxide (NO) is an essential reactive oxygen species and a signal molecule in plants. Although several studies have proposed the occurrence of oxidative NO production, only reductive routes for NO production, such as the nitrate (NO-3) -upper-reductase pathway, have been evidenced to date in land plants. However, plants grown axenically with ammonium as the sole source of nitrogen exhibit contents of nitrite and NO3-, evidencing the existence of a metabolic pathway for oxidative production of NO. We hypothesized that oximes, such as indole-3-acetaldoxime (IAOx), a precursor to indole-3-acetic acid, are intermediate oxidation products in NO synthesis. We detected the production of NO from IAOx and other oximes catalyzed by peroxidase (POD) enzyme using both 4-amino-5-methylamino-2',7'-difluorescein fluorescence and chemiluminescence. Flavins stimulated the reaction, while superoxide dismutase inhibited it. Interestingly, mouse NO synthase can also use IAOx to produce NO at a lower rate than POD. We provided a full mechanism for POD-dependent NO production from IAOx consistent with the experimental data and supported by density functional theory calculations. We showed that the addition of IAOx to extracts from Medicago truncatula increased the in vitro production of NO, while in vivo supplementation of IAOx and other oximes increased the number of lateral roots, as shown for NO donors, and a more than 10-fold increase in IAOx dehydratase expression. Furthermore, we found that in vivo supplementation of IAOx increased NO production in Arabidopsis thaliana wild-type plants, while prx33-34 mutant plants, defective in POD33-34, had reduced production. Our data show that the release of NO by IAOx, as well as its auxinic effect, explain the superroot phenotype. Collectively, our study reveals that plants produce NO utilizing diverse molecules such as oximes, POD, and flavins, which are widely distributed in the plant kingdom, thus introducing a long-awaited oxidative pathway to NO production in plants. This knowledge has essential implications for understanding signaling in biological systems.
Collapse
Affiliation(s)
- Pedro López-Gómez
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Javier Buezo
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Marina Urra
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Alfonso Cornejo
- Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA), Campus de Arrosadía, 31006 Pamplona, Spain
| | - Raquel Esteban
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Sarriena s/n, Apdo. 644, 48080 Bilbao, Spain
| | - Jorge Fernández de Los Reyes
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Estibaliz Urarte
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Estefanía Rodríguez-Dobreva
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Alejandro Chamizo-Ampudia
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Alejandro Eguaras
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain
| | - Sebastian Wolf
- Center for Plant Molecular Biology (ZMBP), University of Tübingen, Geschwister-Scholl-Platz, 72074 Tübingen, Germany
| | - Daniel Marino
- Department of Plant Biology and Ecology, University of the Basque Country (UPV/EHU), Sarriena s/n, Apdo. 644, 48080 Bilbao, Spain
| | - Victor Martínez-Merino
- Institute for Advanced Materials and Mathematics (INAMAT2), Department of Sciences, Public University of Navarre (UPNA), Campus de Arrosadía, 31006 Pamplona, Spain.
| | - Jose F Moran
- Institute for Multidisciplinary Research in Applied Biology (IMAB), Department of Sciences, Public University of Navarre (UPNA), Avda. de Pamplona 123, 31192 Mutilva, Spain.
| |
Collapse
|
2
|
Getino L, Chamizo-Ampudia A, Martín JL, Luengo JM, Barreiro C, Olivera ER. Specific Gene Expression in Pseudomonas Putida U Shows New Alternatives for Cadaverine and Putrescine Catabolism. Genes (Basel) 2023; 14:1897. [PMID: 37895246 PMCID: PMC10606097 DOI: 10.3390/genes14101897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 09/20/2023] [Accepted: 09/27/2023] [Indexed: 10/29/2023] Open
Abstract
Pseudomonas putida strain U can be grown using, as sole carbon sources, the biogenic amines putrescine or cadaverine, as well as their catabolic intermediates, ɣ-aminobutyrate or δ-aminovalerate, respectively. Several paralogs for the genes that encode some of the activities involved in the catabolism of these compounds, such as a putrescine-pyruvate aminotransferase (spuC1 and spuC2 genes) and a ɣ-aminobutyrate aminotransferase (gabT1 and gabT2 genes) have been identified in this bacterium. When the expression pattern of these genes is analyzed by qPCR, it is drastically conditioned by supplying the carbon sources. Thus, spuC1 is upregulated by putrescine, whereas spuC2 seems to be exclusively induced by cadaverine. However, gabT1 increases its expression in response to different polyamines or aminated catabolic derivatives from them (i.e., ɣ-aminobutyrate or δ-aminovalerate), although gabT2 does not change its expression level concerning no-amine unrelated carbon sources (citrate). These results reveal differences between the mechanisms proposed for polyamine catabolism in P. aeruginosa and Escherichia coli concerning P. putida strain U, as well as allow a deeper understanding of the enzymatic systems used by this last strain during polyamine metabolism.
Collapse
Affiliation(s)
| | | | | | | | | | - Elías R. Olivera
- Área de Bioquímica y Biología Molecular, Departamento de Biología Molecular, Universidad de León, 24007 León, Spain; (L.G.); (A.C.-A.); (J.L.M.); (J.M.L.); (C.B.)
| |
Collapse
|
3
|
Chamizo-Ampudia A, Getino L, Luengo JM, Olivera ER. Isolation of Environmental Bacteria Able to Degrade Sterols and/or Bile Acids: Determination of Cholesterol Oxidase and Several Hydroxysteroid Dehydrogenase Activities in Rhodococcus, Gordonia, and Pseudomonas putida. Methods Mol Biol 2023; 2704:25-42. [PMID: 37642836 DOI: 10.1007/978-1-0716-3385-4_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
Interest about the isolation and characterization of steroid-catabolizing bacteria has increased over time due to the massive release of these recalcitrant compounds and their deleterious effects or their biotransformation derivatives as endocrine disruptors for wildlife, as well as their potential use in biotechnological approaches for the synthesis of pharmacological compounds. Thus, in this chapter, an isolation protocol to select environmental bacteria able to degrade sterols, bile acids, and androgens is shown. Moreover, procedures for the determination of cholesterol oxidase or different hydroxysteroid dehydrogenase activities in Pseudomonas putida DOC21, Rhodococcus sp. HE24.12, Gordonia sp. HE24.4J and Gordonia sp. HE24.3 are also detailed.
Collapse
Affiliation(s)
- Alejandro Chamizo-Ampudia
- Área de Bioquímica y Biología Molecular, Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, Spain.
| | - Luis Getino
- Área de Bioquímica y Biología Molecular, Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, Spain
| | - José M Luengo
- Área de Bioquímica y Biología Molecular, Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, Spain
| | - Elias R Olivera
- Área de Bioquímica y Biología Molecular, Departamento de Biología Molecular, Facultad de Veterinaria, Universidad de León, León, Spain
| |
Collapse
|
4
|
Buezo J, Esteban R, Cornejo A, López-Gómez P, Marino D, Chamizo-Ampudia A, Gil MJ, Martínez-Merino V, Moran JF. IAOx induces the SUR phenotype and differential signalling from IAA under different types of nitrogen nutrition in Medicago truncatula roots. Plant Sci 2019; 287:110176. [PMID: 31481210 DOI: 10.1016/j.plantsci.2019.110176] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 06/19/2019] [Accepted: 06/21/2019] [Indexed: 05/22/2023]
Abstract
Indole-3-acetaldoxime (IAOx) is a particularly relevant molecule as an intermediate in the pathway for tryptophan-dependent auxin biosynthesis. The role of IAOx in growth-signalling and root phenotype is poorly studied in cruciferous plants and mostly unknown in non-cruciferous plants. We synthesized IAOx and applied it to M. truncatula plants grown axenically with NO3-, NH4+ or urea as the sole nitrogen source. During 14 days of growth, we demonstrated that IAOx induced an increase in the number of lateral roots, especially under NH4+ nutrition, while elongation of the main root was inhibited. This phenotype is similar to the phenotype known as "superroot" previously described in SUR1- and SUR2-defective Arabidopsis mutants. The effect of IAOx, IAA or the combination of both on the root phenotype was different and dependent on the type of N-nutrition. Our results also showed the endogenous importance of IAOx in a legume plant in relation to IAA metabolism, and suggested IAOx long-distance transport depending on the nitrogen source provided. Finally, our results point out to CYP71A as the major responsible enzymes for IAA synthesis from IAOx, while they exclude indole-3-acetaldehyde oxidases.
Collapse
Affiliation(s)
- Javier Buezo
- Department of Sciences-Institute of Multidisciplinary Applied Biology Research-IMAB, Public University of Navarre, Avenida de Pamplona 123, 31192 Mutilva, Spain.
| | - Raquel Esteban
- Basque Centre for Climate Change (BC3), 48640 Leioa, Spain; University of the Basque Country, UPV/EHU, Sarriena s/n, Apdo. 644, 48080 Bilbao, Spain.
| | - Alfonso Cornejo
- Department of Sciences-Institute for Advance Materials INAMAT, Public University of Navarre, Campus de Arrosadia, 31006 Pamplona, Spain.
| | - Pedro López-Gómez
- Department of Sciences-Institute of Multidisciplinary Applied Biology Research-IMAB, Public University of Navarre, Avenida de Pamplona 123, 31192 Mutilva, Spain.
| | - Daniel Marino
- University of the Basque Country, UPV/EHU, Sarriena s/n, Apdo. 644, 48080 Bilbao, Spain; Ikerbasque, Basque Foundation for Science, E-48011 Bilbao, Spain.
| | - Alejandro Chamizo-Ampudia
- Department of Sciences-Institute of Multidisciplinary Applied Biology Research-IMAB, Public University of Navarre, Avenida de Pamplona 123, 31192 Mutilva, Spain.
| | - María J Gil
- Department of Sciences-Institute for Advance Materials INAMAT, Public University of Navarre, Campus de Arrosadia, 31006 Pamplona, Spain.
| | - Víctor Martínez-Merino
- Department of Sciences-Institute for Advance Materials INAMAT, Public University of Navarre, Campus de Arrosadia, 31006 Pamplona, Spain.
| | - Jose F Moran
- Department of Sciences-Institute of Multidisciplinary Applied Biology Research-IMAB, Public University of Navarre, Avenida de Pamplona 123, 31192 Mutilva, Spain.
| |
Collapse
|
5
|
Llamas A, Chamizo-Ampudia A, Tejada-Jimenez M, Galvan A, Fernandez E. The molybdenum cofactor enzyme mARC: Moonlighting or promiscuous enzyme? Biofactors 2017; 43:486-494. [PMID: 28497908 DOI: 10.1002/biof.1362] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 03/20/2017] [Accepted: 03/28/2017] [Indexed: 12/13/2022]
Abstract
Molybdenum (Mo) is present in the active center of eukaryotic enzymes as a tricyclic pyranopterin chelate compound forming the Mo Cofactor (Moco). Four Moco containing enzymes are known in eukaryotes, nitrate reductase (NR), sulfite oxidase (SO), xanthine oxidoreductase (XOR), and aldehyde oxidase (AO). A fifth Moco enzyme has been recently identified. Because of the ability of this enzyme to convert by reduction several amidoximes prodrugs into their active amino forms, it was named mARC (mitochondrial Amidoxime Reducing Component). This enzyme is also able to catalyze the reduction of a broad range of N-hydroxylated compounds (NHC) as the base analogue 6-hydroxylaminopurine (HAP), as well as nitrite to nitric oxide (NO). All the mARC proteins need reducing power that is supplied by other proteins. The human and plants mARC proteins require a Cytochrome b5 (Cytb5) and a Cytochrome b5 reductase (Cytb5-R) to form an electron transfer chain from NADH to the NHC. Recently, plant mARC proteins were shown to be implicated in the reduction of nitrite to NO, and it was proposed that the electrons required for the reaction were supplied by NR instead of Cytochrome b5 components. This newly characterized mARC activity was termed NO Forming Nitrite Reductase (NOFNiR). Moonlighting proteins form a special class of multifunctional enzymes that can perform more than one function; if the extra function is not physiologically relevant, they are called promiscuous enzymes. In this review, we summarize the current knowledge on the mARC protein, and we propose that mARC is a new moonlighting enzyme. © 2017 BioFactors, 43(4):486-494, 2017.
Collapse
Affiliation(s)
- Angel Llamas
- Dpto. de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Alejandro Chamizo-Ampudia
- Dpto. de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Manuel Tejada-Jimenez
- Dpto. de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Aurora Galvan
- Dpto. de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Emilio Fernandez
- Dpto. de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| |
Collapse
|
6
|
Calatrava V, Chamizo-Ampudia A, Sanz-Luque E, Ocaña-Calahorro F, Llamas A, Fernandez E, Galvan A. How Chlamydomonas handles nitrate and the nitric oxide cycle. J Exp Bot 2017; 68:2593-2602. [PMID: 28201747 DOI: 10.1093/jxb/erw507] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
The green alga Chlamydomonas is a valuable model system capable of assimilating different forms of nitrogen (N). Nitrate (NO3-) has a relevant role in plant-like organisms, first as a nitrogen source for growth and second as a signalling molecule. Several modules are necessary for Chlamydomonas to handle nitrate, including transporters, nitrate reductase (NR), nitrite reductase (NiR), GS/GOGAT enzymes for ammonium assimilation, and regulatory protein(s). Transporters provide a first step for influx/efflux, homeostasis, and sensing of nitrate; and NIT2 is the key transcription factor (RWP-RK) for mediating the nitrate-dependent activation of a number of genes. Here, we review how NR participates in the cycle NO3- →NO2- →NO →NO3-. NR uses the partner protein amidoxime-reducing component/nitric oxide-forming nitrite reductase (ARC/NOFNiR) for the conversion of nitrite (NO2-) into nitric oxide (NO). It also uses the truncated haemoglobin THB1 in the conversion of nitric oxide to nitrate. Nitric oxide is a negative signal for nitrate assimilation; it inhibits the activity and expression of high-affinity nitrate/nitrite transporters and NR. During this cycle, the positive signal of nitrate is transformed into the negative signal of nitric oxide, which can then be converted back into nitrate. Thus, NR is back in the spotlight as a strategic regulator of the nitric oxide cycle and the nitrate assimilation pathway.
Collapse
Affiliation(s)
- Victoria Calatrava
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Alejandro Chamizo-Ampudia
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Emanuel Sanz-Luque
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Francisco Ocaña-Calahorro
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Angel Llamas
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Emilio Fernandez
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| | - Aurora Galvan
- Departamento de Bioquímica y Biología Molecular, Campus de Rabanales y Campus Internacional de Excelencia Agroalimentario (CeiA3), Edif. Severo Ochoa, Universidad de Córdoba, Spain
| |
Collapse
|
7
|
Chamizo-Ampudia A, Sanz-Luque E, Llamas A, Galvan A, Fernandez E. Nitrate Reductase Regulates Plant Nitric Oxide Homeostasis. Trends Plant Sci 2017; 22:163-174. [PMID: 28065651 DOI: 10.1016/j.tplants.2016.12.001] [Citation(s) in RCA: 215] [Impact Index Per Article: 30.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 11/16/2016] [Accepted: 12/04/2016] [Indexed: 05/18/2023]
Abstract
Nitrate reductase (NR) is a key enzyme for nitrogen acquisition by plants, algae, yeasts, and fungi. Nitrate, its main substrate, is required for signaling and is widely distributed in diverse tissues in plants. In addition, NR has been proposed as an important enzymatic source of nitric oxide (NO). Recently, NR has been shown to play a role in NO homeostasis by supplying electrons from NAD(P)H through its diaphorase/dehydrogenase domain both to a truncated hemoglobin THB1, which scavenges NO by its dioxygenase activity, and to the molybdoenzyme NO-forming nitrite reductase (NOFNiR) that is responsible for NO synthesis from nitrite. We review how NR may play a central role in plant biology by controlling the amounts of NO, a key signaling molecule in plant cells.
Collapse
Affiliation(s)
- Alejandro Chamizo-Ampudia
- Department of Biochemistry and Molecular Biology, University of Cordoba, Campus de Rabanales, School of Sciences, Campus de Excelencia Internacional (CeiA3), Edifico Severo Ochoa, Cordoba, Spain
| | - Emanuel Sanz-Luque
- Department of Biochemistry and Molecular Biology, University of Cordoba, Campus de Rabanales, School of Sciences, Campus de Excelencia Internacional (CeiA3), Edifico Severo Ochoa, Cordoba, Spain; Present address: Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Angel Llamas
- Department of Biochemistry and Molecular Biology, University of Cordoba, Campus de Rabanales, School of Sciences, Campus de Excelencia Internacional (CeiA3), Edifico Severo Ochoa, Cordoba, Spain
| | - Aurora Galvan
- Department of Biochemistry and Molecular Biology, University of Cordoba, Campus de Rabanales, School of Sciences, Campus de Excelencia Internacional (CeiA3), Edifico Severo Ochoa, Cordoba, Spain
| | - Emilio Fernandez
- Department of Biochemistry and Molecular Biology, University of Cordoba, Campus de Rabanales, School of Sciences, Campus de Excelencia Internacional (CeiA3), Edifico Severo Ochoa, Cordoba, Spain.
| |
Collapse
|
8
|
Chamizo-Ampudia A, Sanz-Luque E, Llamas Á, Ocaña-Calahorro F, Mariscal V, Carreras A, Barroso JB, Galván A, Fernández E. A dual system formed by the ARC and NR molybdoenzymes mediates nitrite-dependent NO production in Chlamydomonas. Plant Cell Environ 2016; 39:2097-107. [PMID: 26992087 DOI: 10.1111/pce.12739] [Citation(s) in RCA: 89] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 03/08/2016] [Accepted: 03/09/2016] [Indexed: 05/20/2023]
Abstract
Nitric oxide (NO) is a relevant signal molecule involved in many plant processes. However, the mechanisms and proteins responsible for its synthesis are scarcely known. In most photosynthetic organisms NO synthases have not been identified, and Nitrate Reductase (NR) has been proposed as the main enzymatic NO source, a process that in vitro is also catalysed by other molybdoenzymes. By studying transcriptional regulation, enzyme approaches, activity assays with in vitro purified proteins and in vivo and in vitro NO determinations, we have addressed the role of NR and Amidoxime Reducing Component (ARC) in the NO synthesis process. N\R and ARC were intimately related both at transcriptional and activity level. Thus, arc mutants showed high NIA1 (NR gene) expression and NR activity. Conversely, mutants without active NR displayed an increased ARC expression in nitrite medium. Our results with nia1 and arc mutants and with purified enzymes support that ARC catalyses the NO production from nitrite taking electrons from NR and not from Cytb5-1/Cytb5-Reductase, the component partners previously described for ARC (proposed as NOFNiR, Nitric Oxide-Forming Nitrite Reductase). This NR-ARC dual system would be able to produce NO in the presence of nitrate, condition under which NR is unable to do it.
Collapse
Affiliation(s)
- Alejandro Chamizo-Ampudia
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, Córdoba, 14071, Spain
| | - Emanuel Sanz-Luque
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, Córdoba, 14071, Spain
| | - Ángel Llamas
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, Córdoba, 14071, Spain
| | - Francisco Ocaña-Calahorro
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, Córdoba, 14071, Spain
| | - Vicente Mariscal
- Institute of Plant Biochemistry and Photosynthesis, C.S.I.C. and University of Sevilla, Américo Vespucio 49, Sevilla, 41092, Spain
| | - Alfonso Carreras
- Group of Biochemistry and Cell Signaling in Nitric Oxide. Department of Biochemistry and Molecular Biology, Campus 'Las Lagunillas', E-23071, University of Jaén, Jaén, Spain
| | - Juan B Barroso
- Group of Biochemistry and Cell Signaling in Nitric Oxide. Department of Biochemistry and Molecular Biology, Campus 'Las Lagunillas', E-23071, University of Jaén, Jaén, Spain
| | - Aurora Galván
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, Córdoba, 14071, Spain
| | - Emilio Fernández
- Department of Biochemistry and Molecular Biology, University of Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, Córdoba, 14071, Spain.
| |
Collapse
|
9
|
Sanz-Luque E, Ocaña-Calahorro F, de Montaigu A, Chamizo-Ampudia A, Llamas Á, Galván A, Fernández E. THB1, a truncated hemoglobin, modulates nitric oxide levels and nitrate reductase activity. Plant J 2015; 81:467-79. [PMID: 25494936 DOI: 10.1111/tpj.12744] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 11/21/2014] [Accepted: 12/02/2014] [Indexed: 05/18/2023]
Abstract
Hemoglobins are ubiquitous proteins that sense, store and transport oxygen, but the physiological processes in which they are implicated is currently expanding. Recent examples of previously unknown hemoglobin functions, which include scavenging of the signaling molecule nitric oxide (NO), illustrate how the implication of hemoglobins in different cell signaling processes is only starting to be unraveled. The extent and diversity of the hemoglobin protein family suggest that hemoglobins have diverged and have potentially evolved specialized functions in certain organisms. A unique model organism to study this functional diversity at the cellular level is the green alga Chlamydomonas reinhardtii because, among other reasons, it contains an unusually high number of a particular type of hemoglobins known as truncated hemoglobins (THB1-THB12). Here, we reveal a cell signaling function for a truncated hemoglobin of Chlamydomonas that affects the nitrogen assimilation pathway by simultaneously modulating NO levels and nitrate reductase (NR) activity. First, we found that THB1 and THB2 expression is modulated by the nitrogen source and depends on NIT2, a transcription factor required for nitrate assimilation genes expression. Furthermore, THB1 is highly expressed in the presence of NO and is able to convert NO into nitrate in vitro. Finally, THB1 is maintained on its active and reduced form by NR, and in vivo lower expression of THB1 results in increased NR activity. Thus, THB1 plays a dual role in NO detoxification and in the modulation of NR activity. This mechanism can partly explain how NO inhibits NR post-translationally.
Collapse
Affiliation(s)
- Emanuel Sanz-Luque
- Departamento de Bioquímica y Biología Molecular, Facultad de Ciencias, Universidad de Córdoba, Campus de Rabanales, Campus de excelencia internacional (CeiA3), Edif. Severo Ochoa, 14071, Córdoba, Spain
| | | | | | | | | | | | | |
Collapse
|
10
|
Sanz-Luque E, Chamizo-Ampudia A, Llamas A, Galvan A, Fernandez E. Understanding nitrate assimilation and its regulation in microalgae. Front Plant Sci 2015; 6:899. [PMID: 26579149 PMCID: PMC4620153 DOI: 10.3389/fpls.2015.00899] [Citation(s) in RCA: 139] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Accepted: 10/09/2015] [Indexed: 05/02/2023]
Abstract
Nitrate assimilation is a key process for nitrogen (N) acquisition in green microalgae. Among Chlorophyte algae, Chlamydomonas reinhardtii has resulted to be a good model system to unravel important facts of this process, and has provided important insights for agriculturally relevant plants. In this work, the recent findings on nitrate transport, nitrate reduction and the regulation of nitrate assimilation are presented in this and several other algae. Latest data have shown nitric oxide (NO) as an important signal molecule in the transcriptional and posttranslational regulation of nitrate reductase and inorganic N transport. Participation of regulatory genes and proteins in positive and negative signaling of the pathway and the mechanisms involved in the regulation of nitrate assimilation, as well as those involved in Molybdenum cofactor synthesis required to nitrate assimilation, are critically reviewed.
Collapse
|
11
|
|