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Dick CF, Alcantara CL, Carvalho-Kelly LF, Lacerda-Abreu MA, Cunha-E-Silva NL, Meyer-Fernandes JR, Vieyra A. Iron Uptake Controls Trypanosoma cruzi Metabolic Shift and Cell Proliferation. Antioxidants (Basel) 2023; 12:antiox12050984. [PMID: 37237850 DOI: 10.3390/antiox12050984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 05/28/2023] Open
Abstract
(1) Background: Ionic transport in Trypanosoma cruzi is the object of intense studies. T. cruzi expresses a Fe-reductase (TcFR) and a Fe transporter (TcIT). We investigated the effect of Fe depletion and Fe supplementation on different structures and functions of T. cruzi epimastigotes in culture. (2) Methods: We investigated growth and metacyclogenesis, variations of intracellular Fe, endocytosis of transferrin, hemoglobin, and albumin by cell cytometry, structural changes of organelles by transmission electron microscopy, O2 consumption by oximetry, mitochondrial membrane potential measuring JC-1 fluorescence at different wavelengths, intracellular ATP by bioluminescence, succinate-cytochrome c oxidoreductase following reduction of ferricytochrome c, production of H2O2 following oxidation of the Amplex® red probe, superoxide dismutase (SOD) activity following the reduction of nitroblue tetrazolium, expression of SOD, elements of the protein kinase A (PKA) signaling, TcFR and TcIT by quantitative PCR, PKA activity by luminescence, glyceraldehyde-3-phosphate dehydrogenase abundance and activity by Western blotting and NAD+ reduction, and glucokinase activity recording NADP+ reduction. (3) Results: Fe depletion increased oxidative stress, inhibited mitochondrial function and ATP formation, increased lipid accumulation in the reservosomes, and inhibited differentiation toward trypomastigotes, with the simultaneous metabolic shift from respiration to glycolysis. (4) Conclusion: The processes modulated for ionic Fe provide energy for the T. cruzi life cycle and the propagation of Chagas disease.
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Affiliation(s)
- Claudia F Dick
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro/CENABIO, Rio de Janeiro 21941-902, RJ, Brazil
| | - Carolina L Alcantara
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro/CENABIO, Rio de Janeiro 21941-902, RJ, Brazil
| | - Luiz F Carvalho-Kelly
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Marco Antonio Lacerda-Abreu
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Narcisa L Cunha-E-Silva
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro/CENABIO, Rio de Janeiro 21941-902, RJ, Brazil
| | - José R Meyer-Fernandes
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
| | - Adalberto Vieyra
- Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-902, RJ, Brazil
- Centro Nacional de Biologia Estrutural e Bioimagem, Universidade Federal do Rio de Janeiro/CENABIO, Rio de Janeiro 21941-902, RJ, Brazil
- Programa de Pós-Graduação em Biomedicina Translacional /BIOTRANS, Universidade do Grande Rio, Duque de Caxias 25071-202, RJ, Brazil
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Lei Y, Fu S, Yang Y, Chen J, Li B, Guo Z, Ye J. Identification and Functional Analysis of Tartrate-Resistant Acid Phosphatase Type 5b (TRAP5b) in Oreochromis niloticus. Int J Mol Sci 2023; 24:7179. [PMID: 37108342 PMCID: PMC10138680 DOI: 10.3390/ijms24087179] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Revised: 04/05/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Tartrate-resistant acid phosphatase type 5 (TRAP5) is an enzyme that is highly expressed in activated macrophages and osteoclasts and plays important biological functions in mammalian immune defense systems. In the study, we investigated the functions of tartrate-resistant acid phosphatase type 5b from Oreochromis niloticus (OnTRAP5b). The OnTRAP5b gene has an open reading frame of 975 bp, which encodes a mature peptide consisting of 302 amino acids with a molecular weight of 33.448 kDa. The OnTRAP5b protein contains a metallophosphatase domain with metal binding and active sites. Phylogenetic analysis revealed that OnTRAP5b is clustered with TRAP5b of teleost fish and shares a high amino acid sequence similarity with other TRAP5b in teleost fish (61.73-98.15%). Tissues expression analysis showed that OnTRAP5b was most abundant in the liver and was also widely expressed in other tissues. Upon challenge with Streptococcus agalactiae and Aeromonas hydrophila in vivo and in vitro, the expression of OnTRAP5b was significantly up-regulated. Additionally, the purified recombinant OnTRAP5b ((r)OnTRAP5) protein exhibited optimal phosphatase activity at pH 5.0 and an ideal temperature of 50 °C. The Vmax, Km, and kcat of purified (r)OnTRAP5b were found to be 0.484 μmol × min-1 × mg-1, 2.112 mM, and 0.27 s-1 with respect to pNPP as a substrate, respectively. Its phosphatase activity was differentially affected by metal ions (K+, Na+, Mg2+, Ca2+, Mn2+, Cu2+, Zn2+, and Fe3+) and inhibitors (sodium tartrate, sodium fluoride, and EDTA). Furthermore, (r)OnTRAP5b was found to promote the expression of inflammatory-related genes in head kidney macrophages and induce reactive oxygen expression and phagocytosis. Moreover, OnTRAP5b overexpression and knockdown had a significant effect on bacterial proliferation in vivo. When taken together, our findings suggest that OnTRAP5b plays a significant role in the immune response against bacterial infection in Nile tilapia.
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Affiliation(s)
- Yang Lei
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Shengli Fu
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangdong Provincial Engineering Technology Research Center for Environmentally-Friendly Aquaculture, South China Normal University, Guangzhou 510631, China
| | - Yanjian Yang
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Jianlin Chen
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Bingxi Li
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Zheng Guo
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
| | - Jianmin Ye
- Guangzhou Key Laboratory of Subtropical Biodiversity and Biomonitoring, Institute of Modern Aquaculture Science and Engineering, School of Life Sciences, South China Normal University, Guangzhou 510631, China
- Guangdong Provincial Engineering Technology Research Center for Environmentally-Friendly Aquaculture, South China Normal University, Guangzhou 510631, China
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Lei Y, Cao Z, Hou Y, Du X, Zhang H, Du H, Zhou Y, Sun Y. Molecular characterization and functional analysis of tartrate-resistant acid phosphatase (ACP5) gene in red drum (Sciaenops ocellatus). FISH & SHELLFISH IMMUNOLOGY 2023; 132:108495. [PMID: 36566835 DOI: 10.1016/j.fsi.2022.108495] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 12/08/2022] [Accepted: 12/12/2022] [Indexed: 06/17/2023]
Abstract
Tartrate-resistant acid phosphatase (ACP5) plays an important biological function in immune defense and is highly expressed in activated macrophages, osteoclasts and dendritic cells. In teleost, the functionality of ACP5 remains to be revealed. In this study, we cloned and identified SoACP5 from red drum (Sciaenops ocellatus) and analyzed its function in vivo and in vitro. The open reading frame of SoACP5 is 1002 bp in length, encoding 333 amino acids. SoACP5 shares high sequence identities (96.70%-49.25%) with ACP5 of other species. The SoACP5 mRNA was widely distributed in collected tissues of healthy red drum, and with the maximum in gills. The expression of SoACP5 increased significantly in vivo following challenge with Edwardsiella tarda. Moreover, the recombinant SoACP5 protein (rSoACP5) was purified with his-tag band resin columns, and confirmed to have phosphatase activity which was optimal at pH 5 and 55 °C. Various metal ions (K+, Zn2+, Mn2+, Mg2+, Ca2+, Cu2+, Fe2+ and Fe3+) have different effects on phosphatase activity. rSoACP5 induced the cellular proliferation of peripheral blood leukocytes. The over-expression and knockdown of SoACP5 in vivo had a significant effect on bacterial proliferation. Furthermore, both of the antibacterial activity and phosphatase activity were decreased when the reducedSoACP5 was oxidized by H2O2. In summary, the present study indicated that SoACP5 is likely involved in host defense against bacterial infection in S. ocellatus.
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Affiliation(s)
- Yang Lei
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China
| | - Zhenjie Cao
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Collaborative Innovation Center of Marine Science and Technology, Hainan University, Haikou, 570228, PR China
| | - Yongwei Hou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, College of Marine Science, Hainan University, Haikou, 570228, PR China
| | - Xiangyu Du
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, College of Marine Science, Hainan University, Haikou, 570228, PR China
| | - Han Zhang
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, College of Marine Science, Hainan University, Haikou, 570228, PR China
| | - Hehe Du
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, College of Marine Science, Hainan University, Haikou, 570228, PR China
| | - Yongcan Zhou
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Collaborative Innovation Center of Marine Science and Technology, Hainan University, Haikou, 570228, PR China; Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, College of Marine Science, Hainan University, Haikou, 570228, PR China.
| | - Yun Sun
- State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, 570228, PR China; Collaborative Innovation Center of Marine Science and Technology, Hainan University, Haikou, 570228, PR China; Hainan Provincial Key Laboratory for Tropical Hydrobiology and Biotechnology, College of Marine Science, Hainan University, Haikou, 570228, PR China.
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Carvalho-de-Araújo AD, Carvalho-Kelly LF, Dick CF, Meyer-Fernandes JR. Inorganic phosphate transporter in Giardia duodenalis and its possible role in ATP synthesis. Mol Biochem Parasitol 2022; 251:111504. [PMID: 35843419 DOI: 10.1016/j.molbiopara.2022.111504] [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: 03/04/2022] [Revised: 06/14/2022] [Accepted: 07/13/2022] [Indexed: 10/17/2022]
Abstract
Giardia duodenalis is a flagellated protozoan that inhabits vertebrate host intestines, causing the disease known as giardiasis. Similar to other parasites, G. duodenalis must take advantage of environmental resources to survive, such as inorganic phosphate (Pi) availability. Pi is an anionic molecule and an essential nutrient for all organisms because it participates in the biosynthesis of biomolecules, energy storage, and cellular structure formation. The first step in Pi metabolism is its uptake through specific transporters on the plasma membrane. We identified a symporter H+:Pi-type ORF sequence in the G. duodenalis genome (GenBank ID: GL50803_5164), named GdPho84, which is homologous to Saccharomyces cerevisiae PHO84. In trophozoites, Pi transport was linear for up to 15 min, and the cell density was 3 × 107 cells/ml. Physiological variations in pH (6.4-8.0) did not influence Pi uptake. This Pi transporter had a high affinity, with K0.5 = 67.7 ± 7.1 µM Pi. SCH28080 (inhibitor of H+, K+-ATPase), bafilomycin A1 (inhibitor of vacuolar H+-ATPase), and FCCP (H+ ionophore) were able to inhibit Pi transport, indicating that an H+ gradient in the cell powered uphill Pi movement. PAA, an H+-dependent Pi transport inhibitor, reduced cell proliferation, Pi transport activity, and GdPHO48 mRNA levels. Pi starvation stimulated membrane potential-sensitive Pi uptake coupled to H+ fluxes, increased GdPho84 expression, and reduced intracellular ATP levels. These events indicate that these cells had an increased capacity to internalize Pi as a compensatory mechanism compared to cells maintained in control medium conditions. Internalized Pi can be used in glycolytic metabolism once iodoacetamide (GAPDH inhibitor) inhibits Pi influx. Together, these results reinforce the hypothesis that Pi is a crucial nutrient for G. duodenalis energy metabolism.
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Affiliation(s)
| | - Luiz Fernando Carvalho-Kelly
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil
| | - Claudia F Dick
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil.
| | - José Roberto Meyer-Fernandes
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902 Rio de Janeiro, Brazil.
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Dick CF, Rocco-Machado N, Dos-Santos ALA, Carvalho-Kelly LF, Alcantara CL, Cunha-E-Silva NL, Meyer-Fernandes JR, Vieyra A. An Iron Transporter Is Involved in Iron Homeostasis, Energy Metabolism, Oxidative Stress, and Metacyclogenesis in Trypanosoma cruzi. Front Cell Infect Microbiol 2022; 11:789401. [PMID: 35083166 PMCID: PMC8785980 DOI: 10.3389/fcimb.2021.789401] [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: 10/04/2021] [Accepted: 12/06/2021] [Indexed: 11/29/2022] Open
Abstract
The parasite Trypanosoma cruzi causes Chagas’ disease; both heme and ionic Fe are required for its optimal growth, differentiation, and invasion. Fe is an essential cofactor in many metabolic pathways. Fe is also harmful due to catalyzing the formation of reactive O2 species; for this reason, all living systems develop mechanisms to control the uptake, metabolism, and storage of Fe. However, there is limited information available on Fe uptake by T. cruzi. Here, we identified a putative 39-kDa Fe transporter in T. cruzi genome, TcIT, homologous to the Fe transporter in Leishmania amazonensis and Arabidopsis thaliana. Epimastigotes grown in Fe-depleted medium have increased TcIT transcription compared with controls grown in regular medium. Intracellular Fe concentration in cells maintained in Fe-depleted medium is lower than in controls, and there is a lower O2 consumption. Epimastigotes overexpressing TcIT, which was encountered in the parasite plasma membrane, have high intracellular Fe content, high O2 consumption—especially in phosphorylating conditions, high intracellular ATP, very high H2O2 production, and stimulated transition to trypomastigotes. The investigation of the mechanisms of Fe transport at the cellular and molecular levels will assist in elucidating Fe metabolism in T. cruzi and the involvement of its transport in the differentiation from epimastigotes to trypomastigotes, virulence, and maintenance/progression of the infection.
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Affiliation(s)
- Claudia F Dick
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Nathália Rocco-Machado
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - André L A Dos-Santos
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Luiz F Carvalho-Kelly
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carolina L Alcantara
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Narcisa L Cunha-E-Silva
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - José R Meyer-Fernandes
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Institute of Biophysics, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,National Center of Structural Biology and Bioimaging (CENABIO), Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,Graduate Program in Translational Biomedicine/BIOTRANS, Unigranrio University, Duque de Caxias, Brazil
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Parasite protein phosphatases: biological function, virulence, and host immune evasion. Parasitol Res 2021; 120:2703-2715. [PMID: 34309709 DOI: 10.1007/s00436-021-07259-9] [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: 02/09/2021] [Accepted: 07/18/2021] [Indexed: 10/20/2022]
Abstract
Protein phosphatases are enzymes that dephosphorylate tyrosine and serine/threonine amino acid residues. Although their role in cellular processes has been best characterized in higher eukaryotes, they have also been identified and studied in different pathogenic microorganisms (e.g., parasites) in the last two decades. Whereas some parasite protein phosphatases carry out functions similar to those of their homologs in yeast and mammalian cells, others have unique structural and/or functional characteristics. Thus, the latter unique phosphatases may be instrumental as targets for drug therapy or as markers for diagnosis. It is important to better understand the involvement of protein phosphatases in parasites in relation to their cell cycle, metabolism, virulence, and evasion of the host immune response. The up-to-date information about parasite phosphatases of medical and veterinarian relevance is herein reviewed.
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Dick CF, de Moura Guimarães L, Carvalho-Kelly LF, Cortes AL, da Silva Lara Morcillo L, da Silva Sampaio L, Meyer-Fernandes JR, Vieyra A. A ferric reductase of Trypanosoma cruzi (TcFR) is involved in iron metabolism in the parasite. Exp Parasitol 2020; 217:107962. [PMID: 32763249 DOI: 10.1016/j.exppara.2020.107962] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 07/21/2020] [Accepted: 07/27/2020] [Indexed: 01/05/2023]
Abstract
Trypanosoma cruzi is a parasitic protozoan that infects various species of domestic and wild animals, triatomine bugs and humans. It is the etiological agent of American trypanosomiasis, also known as Chagas Disease, which affects about 17 million people in Latin America and is emerging elsewhere in the world. Iron (Fe) is a crucial micronutrient for almost all cells, acting as a cofactor for several metabolic enzymes. T. cruzi has a high requirement for Fe, using heminic and non-heminic Fe for growth and differentiation. Fe occurs in the oxidized (Fe3+) form in aerobic environments and needs to be reduced to Fe2+ before it enters cells. Fe-reductase, located in the plasma membranes of some organisms, catalyzes the Fe3+⇒ Fe2+ conversion. In the present study we found an amino acid sequence in silico that allowed us to identify a novel 35 kDa protein in T. cruzi with two transmembrane domains in the C-terminal region containing His residues that are conserved in the Ferric Reductase Domain Superfamily and are required for catalyzing Fe3+ reduction. Accordingly, we named this protein TcFR. Intact epimastigotes from the T. cruzi DM28c strain reduced the artificial Fe3+-containing substrate potassium ferricyanide in a cell density-dependent manner, following Michaelis-Menten kinetics. The TcFR activity was more than eightfold higher in a plasma membrane-enriched fraction than in whole homogenates, and this increase was consistent with the intensity of the 35 kDa band on Western blotting images obtained using anti-NOX5 raised against the human antigen. Immunofluorescence experiments demonstrated TcFR on the parasite surface. That TcFR is part of a catalytic complex allowing T. cruzi to take up Fe from the medium was confirmed by experiments in which DM28c was assayed after culturing in Fe-depleted medium: (i) proliferation during the stationary growth phase was five times slower; (ii) the relative expression of TcFR (qPCR) was 50% greater; (iii) intact cells had 120% higher Fe-reductase activity. This ensemble of results indicates that TcFR is a conserved enzyme in T. cruzi, and its catalytic properties are modulated in order to respond to external Fe fluctuations.
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Affiliation(s)
- Claudia F Dick
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; Carlos Chagas Filho Institute of Biophysics,Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; National Center of Structural Biology and Bioimaging, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil.
| | - Lídia de Moura Guimarães
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; National Institute of Science and Technology for Structural Biology, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - Luiz Fernando Carvalho-Kelly
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; National Institute of Science and Technology for Structural Biology, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - Aline Leal Cortes
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | | | - Luzia da Silva Sampaio
- Carlos Chagas Filho Institute of Biophysics,Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - José Roberto Meyer-Fernandes
- Leopoldo de Meis Institute of Medical Biochemistry, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; National Institute of Science and Technology for Structural Biology, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil
| | - Adalberto Vieyra
- Carlos Chagas Filho Institute of Biophysics,Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; National Center of Structural Biology and Bioimaging, Federal University of Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil; Graduate Program in Translational Biomedicine, Grande Rio University, 25071-202, Duque de Caxias, Brazil
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