1
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Currie MJ, Davies JS, Scalise M, Gulati A, Wright JD, Newton-Vesty MC, Abeysekera GS, Subramanian R, Wahlgren WY, Friemann R, Allison JR, Mace PD, Griffin MDW, Demeler B, Wakatsuki S, Drew D, Indiveri C, Dobson RCJ, North RA. Structural and biophysical analysis of a Haemophilus influenzae tripartite ATP-independent periplasmic (TRAP) transporter. eLife 2024; 12:RP92307. [PMID: 38349818 PMCID: PMC10942642 DOI: 10.7554/elife.92307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2024] Open
Abstract
Tripartite ATP-independent periplasmic (TRAP) transporters are secondary-active transporters that receive their substrates via a soluble-binding protein to move bioorganic acids across bacterial or archaeal cell membranes. Recent cryo-electron microscopy (cryo-EM) structures of TRAP transporters provide a broad framework to understand how they work, but the mechanistic details of transport are not yet defined. Here we report the cryo-EM structure of the Haemophilus influenzae N-acetylneuraminate TRAP transporter (HiSiaQM) at 2.99 Å resolution (extending to 2.2 Å at the core), revealing new features. The improved resolution (the previous HiSiaQM structure is 4.7 Å resolution) permits accurate assignment of two Na+ sites and the architecture of the substrate-binding site, consistent with mutagenic and functional data. Moreover, rather than a monomer, the HiSiaQM structure is a homodimer. We observe lipids at the dimer interface, as well as a lipid trapped within the fusion that links the SiaQ and SiaM subunits. We show that the affinity (KD) for the complex between the soluble HiSiaP protein and HiSiaQM is in the micromolar range and that a related SiaP can bind HiSiaQM. This work provides key data that enhances our understanding of the 'elevator-with-an-operator' mechanism of TRAP transporters.
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Affiliation(s)
- Michael J Currie
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - James S Davies
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of CalabriaArcavacata di RendeItaly
| | - Ashutosh Gulati
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Joshua D Wright
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Michael C Newton-Vesty
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Gayan S Abeysekera
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
| | - Ramaswamy Subramanian
- Biological Sciences and Biomedical Engineering, Bindley Bioscience Center, Purdue University West LafayetteWest LafayetteUnited States
| | - Weixiao Y Wahlgren
- Department of Chemistry and Molecular Biology, Biochemistry and Structural Biology, University of GothenburgGothenburgSweden
| | - Rosmarie Friemann
- Centre for Antibiotic Resistance Research (CARe) at University of GothenburgGothenburgSweden
| | - Jane R Allison
- Biomolecular Interaction Centre, Digital Life Institute, Maurice Wilkins Centre for Molecular Biodiscovery, and School of Biological Sciences, University of AucklandAucklandNew Zealand
| | - Peter D Mace
- Biochemistry Department, School of Biomedical Sciences, University of OtagoDunedinNew Zealand
| | - Michael DW Griffin
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of MelbourneMelbourneAustralia
| | - Borries Demeler
- Department of Chemistry and Biochemistry, University of MontanaMissoulaUnited States
- Department of Chemistry and Biochemistry, University of LethbridgeLethbridgeCanada
| | - Soichi Wakatsuki
- Biological Sciences Division, SLAC National Accelerator LaboratoryMenlo ParkUnited States
- Department of Structural Biology, Stanford University School of MedicineStanfordUnited States
| | - David Drew
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of CalabriaArcavacata di RendeItaly
- CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM)BariItaly
| | - Renwick CJ Dobson
- Biomolecular Interaction Centre, Maurice Wilkins Centre for Biodiscovery, MacDiarmid Institute for Advanced Materials and Nanotechnology, and School of Biological Sciences, University of CanterburyChristchurchNew Zealand
- ARC Centre for Cryo-electron Microscopy of Membrane Proteins, Bio Molecular Science and Biotechnology Institute, Department of Biochemistry and Pharmacology, University of MelbourneMelbourneAustralia
| | - Rachel A North
- Department of Biochemistry and Biophysics, Stockholm UniversityStockholmSweden
- School of Medical Sciences, Faculty of Medicine and Health, University of SydneySydneyAustralia
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2
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Proline transporters ProT and PutP are required for Staphylococcus aureus infection. PLoS Pathog 2023; 19:e1011098. [PMID: 36652494 PMCID: PMC9886301 DOI: 10.1371/journal.ppat.1011098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Revised: 01/30/2023] [Accepted: 01/03/2023] [Indexed: 01/19/2023] Open
Abstract
Proline acquired via specific transporters can serve as a proteinogenic substrate, carbon and nitrogen source, or osmolyte. Previous reports have documented that Staphylococcus aureus, a major community and nosocomial pathogen, encodes at least four proline transporters, PutP, OpuC, OpuD, and ProP. A combination of genetic approaches and 3H-proline transport assays reveal that a previously unrecognized transporter, ProT, in addition to PutP, are the major proline transporters in S. aureus. Complementation experiments using constitutively expressed non-cognate promoters found that proline transport via OpuD, OpuC, and ProP is minimal. Both proline biosynthesis from arginine and proline transport via ProT are critical for growth when S. aureus is grown under conditions of high salinity. Further, proline transport mediated by ProT or PutP are required for growth in media with and without glucose, indicating both transporters function to acquire proline for proteinogenic purposes in addition to acquisition of proline as a carbon/nitrogen source. Lastly, inactivation of proT and putP resulted in a significant reduction (5 log10) of bacterial burden in murine skin-and-soft tissue infection and bacteremia models, suggesting that proline transport is required to establish a S. aureus infection.
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3
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Taylor JA, Díez-Vives C, Nielsen S, Wemheuer B, Thomas T. Communality in microbial stress response and differential metabolic interactions revealed by time-series analysis of sponge symbionts. Environ Microbiol 2022; 24:2299-2314. [PMID: 35229422 DOI: 10.1111/1462-2920.15962] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2021] [Revised: 02/13/2022] [Accepted: 02/26/2022] [Indexed: 11/03/2022]
Abstract
The diversity and function of sponge-associated symbionts is now increasingly understood, however, we lack an understanding on how they dynamically behave to ensure holobiont stability in the face of environmental variation. Here we performed a metatransciptomics analysis of three microbial symbionts of the sponge Cymbastela concentrica in situ over 14 months and through differential gene expression and correlation analysis to environmental variables uncovered differences that speak to their metabolic activities and level of symbiotic and environmental interactions. The nitrite-oxidising Ca. Porinitrospira cymbastela maintained a seemingly stable metabolism, with the few differentially expressed genes related only to stress responses. The heterotrophic Ca. Porivivens multivorans displayed differential use of holobiont-derived compounds and respiration modes, while the ammonium-oxidising archaeon Ca. Nitrosopumilus cymbastelus differentially expressed genes related to phosphate metabolism and symbiosis effectors. One striking similarity between the symbionts was their similar variation in expression of stress-related genes. Our timeseries study showed that the microbial community of C. concentrica undertakes dynamic gene expression adjustments in response to the surroundings, tuned to deal with general stress and metabolic interactions between holobiont members. The success of these dynamic adjustments likely underpins the stability of the sponge holobiont and may provide resilience against environmental change. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jessica A Taylor
- Centre for Marine Science and Innovation, University of New South Wales, Sydney, Australia.,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, Australia
| | - Cristina Díez-Vives
- Centre for Marine Science and Innovation, University of New South Wales, Sydney, Australia.,Department of Biodiversity and Evolutionary Biology, Museo Nacional de Ciencias Naturales, Madrid, Spain
| | - Shaun Nielsen
- Centre for Marine Science and Innovation, University of New South Wales, Sydney, Australia
| | - Bernd Wemheuer
- Centre for Marine Science and Innovation, University of New South Wales, Sydney, Australia.,School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
| | - Torsten Thomas
- Centre for Marine Science and Innovation, University of New South Wales, Sydney, Australia.,School of Biological, Earth and Environmental Sciences, University of New South Wales, Sydney, Australia
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4
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Wirtz L, Eder M, Brand AK, Jung H. HutT functions as the major L-histidine transporter in Pseudomonas putida KT2440. FEBS Lett 2021; 595:2113-2126. [PMID: 34245008 DOI: 10.1002/1873-3468.14159] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/01/2021] [Accepted: 07/06/2021] [Indexed: 11/06/2022]
Abstract
Histidine is an important carbon and nitrogen source of γ-proteobacteria and can affect bacteria-host interactions. The mechanisms of histidine uptake are only partly understood. Here, we analyze functional properties of the putative histidine transporter HutT of the soil bacterium Pseudomonas putida. The hutT gene is part of the histidine utilization operon, and the gene product belongs to the amino acid-polyamine-organocation (APC) family of secondary transporters. Deletion of hutT severely impairs growth of P. putida on histidine, suggesting that the encoded transporter is the major histidine uptake system of P. putida. Transport experiments with cells and purified and reconstituted protein indicate that HutT functions as a high-affinity histidine : proton symporter with high specificity for the amino acid. Substitution analyses identified amino acids crucial for HutT function.
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Affiliation(s)
- Larissa Wirtz
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, Martinsried, Germany
| | - Michelle Eder
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, Martinsried, Germany
| | - Anna-Katharina Brand
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, Martinsried, Germany
| | - Heinrich Jung
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, Martinsried, Germany
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5
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Shimada T, Ogasawara H, Kobayashi I, Kobayashi N, Ishihama A. Single-Target Regulators Constitute the Minority Group of Transcription Factors in Escherichia coli K-12. Front Microbiol 2021; 12:697803. [PMID: 34220787 PMCID: PMC8249747 DOI: 10.3389/fmicb.2021.697803] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 05/28/2021] [Indexed: 11/13/2022] Open
Abstract
The identification of regulatory targets of all transcription factors (TFs) is critical for understanding the entire network of genome regulation. A total of approximately 300 TFs exist in the model prokaryote Escherichia coli K-12, but the identification of whole sets of their direct targets is impossible with use of in vivo approaches. For this end, the most direct and quick approach is to identify the TF-binding sites in vitro on the genome. We then developed and utilized the gSELEX screening system in vitro for identification of more than 150 E. coli TF-binding sites along the E. coli genome. Based on the number of predicted regulatory targets, we classified E. coli K-12 TFs into four groups, altogether forming a hierarchy ranging from a single-target TF (ST-TF) to local TFs, global TFs, and nucleoid-associated TFs controlling as many as 1,000 targets. Using the collection of purified TFs and a library of genome DNA segments from a single and the same E. coli K-12, we identified here a total of 11 novel ST-TFs, CsqR, CusR, HprR, NorR, PepA, PutA, QseA, RspR, UvrY, ZraR, and YqhC. The regulation of single-target promoters was analyzed in details for the hitherto uncharacterized QseA and RspR. In most cases, the ST-TF gene and its regulatory target genes are adjacently located on the E. coli K-12 genome, implying their simultaneous transfer in the course of genome evolution. The newly identified 11 ST-TFs and the total of 13 hitherto identified altogether constitute the minority group of TFs in E. coli K-12.
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Affiliation(s)
| | - Hiroshi Ogasawara
- Research Center for Supports to Advanced Science, Division of Gene Research, Shinshu University, Nagano, Japan.,Research Center for Fungal and Microbial Dynamism, Shinshu University, Nagano, Japan
| | - Ikki Kobayashi
- School of Agriculture, Meiji University, Kawasaki, Japan
| | - Naoki Kobayashi
- Department of Frontier Science, Hosei University, Koganei, Japan
| | - Akira Ishihama
- Department of Frontier Science, Hosei University, Koganei, Japan.,Micro-Nano Technology Research Center, Hosei University, Koganei, Japan
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6
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Kim Y, Lama S, Agrawal D, Kumar V, Park S. Acetate as a potential feedstock for the production of value-added chemicals: Metabolism and applications. Biotechnol Adv 2021; 49:107736. [PMID: 33781888 DOI: 10.1016/j.biotechadv.2021.107736] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 02/22/2021] [Accepted: 03/19/2021] [Indexed: 10/21/2022]
Abstract
Acetate is regarded as a promising carbon feedstock in biological production owing to its possible derivation from C1 gases such as CO, CO2 and methane. To best use of acetate, comprehensive understanding of acetate metabolisms from genes and enzymes to pathways and regulations is needed. This review aims to provide an overview on the potential of acetate as carbon feedstock for industrial biotechnology. Biochemical, microbial and biotechnological aspects of acetate metabolism are described. Especially, the current state-of-the art in the production of value-added chemicals from acetate is summarized. Challenges and future perspectives are also provided.
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Affiliation(s)
- Yeonhee Kim
- School of Energy and Chemical Engineering, UNIST, 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Suman Lama
- School of Energy and Chemical Engineering, UNIST, 50, UNIST-gil, Ulsan 44919, Republic of Korea
| | - Deepti Agrawal
- Biochemistry and Biotechnology Area, Material Resource Efficiency Division, CSIR- Indian Institute of Petroleum, Mohkampur, Dehradun 248005, India
| | - Vinod Kumar
- Centre for Climate and Environmental Protection, School of Water, Energy and Environment, Cranfield University, Cranfield, MK430AL, United Kingdom.
| | - Sunghoon Park
- School of Energy and Chemical Engineering, UNIST, 50, UNIST-gil, Ulsan 44919, Republic of Korea.
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7
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Straub TJ, Chou WC, Manson AL, Schreiber HL, Walker BJ, Desjardins CA, Chapman SB, Kaspar KL, Kahsai OJ, Traylor E, Dodson KW, Hullar MAJ, Hultgren SJ, Khoo C, Earl AM. Limited effects of long-term daily cranberry consumption on the gut microbiome in a placebo-controlled study of women with recurrent urinary tract infections. BMC Microbiol 2021; 21:53. [PMID: 33596852 PMCID: PMC7890861 DOI: 10.1186/s12866-021-02106-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 01/28/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Urinary tract infections (UTIs) affect 15 million women each year in the United States, with > 20% experiencing frequent recurrent UTIs. A recent placebo-controlled clinical trial found a 39% reduction in UTI symptoms among recurrent UTI sufferers who consumed a daily cranberry beverage for 24 weeks. Using metagenomic sequencing of stool from a subset of these trial participants, we assessed the impact of cranberry consumption on the gut microbiota, a reservoir for UTI-causing pathogens such as Escherichia coli, which causes > 80% of UTIs. RESULTS The overall taxonomic composition, community diversity, carriage of functional pathways and gene families, and relative abundances of the vast majority of observed bacterial taxa, including E. coli, were not changed significantly by cranberry consumption. However, one unnamed Flavonifractor species (OTU41), which represented ≤1% of the overall metagenome, was significantly less abundant in cranberry consumers compared to placebo at trial completion. Given Flavonifractor's association with negative human health effects, we sought to determine OTU41 characteristic genes that may explain its differential abundance and/or relationship to key host functions. Using comparative genomic and metagenomic techniques, we identified genes in OTU41 related to transport and metabolism of various compounds, including tryptophan and cobalamin, which have been shown to play roles in host-microbe interactions. CONCLUSION While our results indicated that cranberry juice consumption had little impact on global measures of the microbiome, we found one unnamed Flavonifractor species differed significantly between study arms. This suggests further studies are needed to assess the role of cranberry consumption and Flavonifractor in health and wellbeing in the context of recurrent UTI. TRIAL REGISTRATION Clinical trial registration number: ClinicalTrials.gov NCT01776021 .
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Affiliation(s)
- Timothy J Straub
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
- Department of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Wen-Chi Chou
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Abigail L Manson
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Henry L Schreiber
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Division of Biology & Biological Engineering, California Institute of Technology, Pasadena, CA, USA
| | - Bruce J Walker
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Christopher A Desjardins
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | - Sinéad B Chapman
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA
| | | | - Orsalem J Kahsai
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Elizabeth Traylor
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Karen W Dodson
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | - Meredith A J Hullar
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - Scott J Hultgren
- Department of Molecular Microbiology, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
- Center for Women's Infectious Disease Research, Washington University School of Medicine in St. Louis, St. Louis, MO, USA
| | | | - Ashlee M Earl
- Infectious Disease & Microbiome Program, Broad Institute, 415 Main Street, Cambridge, MA, 02142, USA.
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8
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Transcriptomic Analysis of Staphylococcus xylosus in Solid Dairy Matrix Reveals an Aerobic Lifestyle Adapted to Rind. Microorganisms 2020; 8:microorganisms8111807. [PMID: 33212972 PMCID: PMC7698506 DOI: 10.3390/microorganisms8111807] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Revised: 11/12/2020] [Accepted: 11/14/2020] [Indexed: 11/17/2022] Open
Abstract
Staphylococcus xylosus is found in the microbiota of traditional cheeses, particularly in the rind of soft smeared cheeses. Despite its frequency, the molecular mechanisms allowing the growth and adaptation of S. xylosus in dairy products are still poorly understood. A transcriptomic approach was used to determine how the gene expression profile is modified during the fermentation step in a solid dairy matrix. S. xylosus developed an aerobic metabolism perfectly suited to the cheese rind. It overexpressed genes involved in the aerobic catabolism of two carbon sources in the dairy matrix, lactose and citrate. Interestingly, S. xylosus must cope with nutritional shortage such as amino acids, peptides, and nucleotides, consequently, an extensive up-regulation of genes involved in their biosynthesis was observed. As expected, the gene sigB was overexpressed in relation with general stress and entry into the stationary phase and several genes under its regulation, such as those involved in transport of anions, cations and in pigmentation were up-regulated. Up-regulation of genes encoding antioxidant enzymes and glycine betaine transport and synthesis systems showed that S. xylosus has to cope with oxidative and osmotic stresses. S. xylosus expressed an original system potentially involved in iron acquisition from lactoferrin.
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9
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Kinne R, Spokes KC, Silva P. Sugar uptake, metabolism, and chloride secretion in the rectal gland of the spiny dogfish Squalus acanthias. Am J Physiol Regul Integr Comp Physiol 2020; 319:R96-R105. [PMID: 32459971 DOI: 10.1152/ajpregu.00060.2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The rectal gland of the spiny dogfish Squalus acanthias secretes a salt solution isosmotic with plasma that maintains the salt homeostasis of the fish. It secretes salt against an electrochemical gradient that requires the expenditure of energy. Isolated rectal glands perfused without glucose secrete salt, albeit at a rate about 30% of glands perfused with 5 mM glucose. Gradually reducing the glucose concentration is associated with a progressive decrease in the secretion of chloride. The apparent Km for the exogenous glucose-dependent chloride secretion is around 2 mM. Phloretin and cytochalasin B, agents that inhibit facilitated glucose carriers of the solute carrier 2 (Slc2) family such as glucose transporter 2 (GLUT2), do not inhibit the secretion of chloride by the perfused rectal glands. Phloridzin, which inhibits Slc5 family of glucose symporters, or α-methyl-d-glucoside, which competitively inhibits the uptake of glucose through Slc5 symporters, inhibit the secretion of chloride. Thus the movement of glucose into the rectal gland cells appears to be mediated by a sodium-glucose symporter. Sodium-glucose cotransporter 1 (SGLT1), the first member of the Slc5 family of sodium-linked glucose symporters, was cloned from the rectal gland. No evidence of GLUT2 was found. The persistence of secretion of chloride in the absence of glucose in the perfusate suggests that there is an additional source of energy within the cells. The use of 2-mercapto-acetate did not result in any change in the secretion of chloride, suggesting that the oxidation of fatty acids is not the source of energy for the secretion of chloride. Perfusion of isolated glands with KCN in the absence of glucose further reduces the secretion of chloride but does not abolish it, again suggesting that there is another source of energy within the cells. Glucose was measured in the rectal gland cells and found to be at concentrations in the range of that in the perfusate. Glycogen measurements indicated that there are significant stores of glucose in the rectal gland. Moreover, glycogen synthase was partially cloned from rectal gland cells. The open reading frame of glycogen phosphorylase was also cloned from rectal gland cells. Measurements of glycogen phosphorylase showed that the enzyme is mostly in its active form in the cells. The cells of the rectal gland of the spiny dogfish require exogenous glucose to fully support the active secretion of salt. They have the means to transport glucose into the cells in the form of SGLT1. The cells also have an endogenous supply of glucose as glycogen and have the necessary elements to synthesize, store, and hydrolyze it.
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Affiliation(s)
- Rolf Kinne
- Max-Planck-Institut für Molekulare Physiologie, Dortmund, Germany.,Mount Desert Island Biological Laboratory, Salsbury Cove, Maine
| | - Katherine C Spokes
- Department of Medicine, Beth Israel Hospital, and Harvard Medical School, Boston, Massachusetts.,Mount Desert Island Biological Laboratory, Salsbury Cove, Maine
| | - Patricio Silva
- Department of Medicine, Temple University School of Medicine, Philadelphia, Pennsylvania.,Mount Desert Island Biological Laboratory, Salsbury Cove, Maine
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10
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Wirtz L, Eder M, Schipper K, Rohrer S, Jung H. Transport and kinase activities of CbrA of Pseudomonas putida KT2440. Sci Rep 2020; 10:5400. [PMID: 32214184 PMCID: PMC7096432 DOI: 10.1038/s41598-020-62337-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Accepted: 03/10/2020] [Indexed: 12/20/2022] Open
Abstract
The CbrA/CbrB system is a two-component signal transduction system known to participate in the regulation of the cellular carbon/nitrogen balance and to play a central role in carbon catabolite repression in Pseudomonas species. CbrA is composed of a domain with similarity to proteins of the solute/sodium symporter family (SLC5) and domains typically found in bacterial sensor kinases. Here, the functional properties of the sensor kinase CbrA and its domains are analyzed at the molecular level using the system of the soil bacterium P. putida KT2440 as a model. It is demonstrated that CbrA can bind and transport L-histidine. Transport is specific for L-histidine and probably driven by an electrochemical proton gradient. The kinase domain is not required for L-histidine uptake by the SLC5 domain of CbrA, and has no significant impact on transport kinetics. Furthermore, it is shown that the histidine kinase can autophosphorylate and transfer the phosphoryl group to the response regulator CbrB. The SLC5 domain is not essential for these activities but appears to modulate the autokinase activity. A phosphatase activity of CbrA is not detected. None of the activities is significantly affected by L-histidine. The results demonstrate that CbrA functions as a L-histidine transporter and sensor kinase.
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Affiliation(s)
- Larissa Wirtz
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152, Martinsried, Germany
| | - Michelle Eder
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152, Martinsried, Germany
| | - Kerstin Schipper
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152, Martinsried, Germany.,Institute of Microbiology, Department of Biology, Heinrich-Heine-University, D-40225, Düsseldorf, Germany
| | - Stefanie Rohrer
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152, Martinsried, Germany.,Technical University of Munich, D-80333, Munich, Germany
| | - Heinrich Jung
- Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152, Martinsried, Germany.
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11
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Sayé M, Reigada C, Gauna L, Valera-Vera EA, Pereira CA, Miranda MR. Amino Acid and Polyamine Membrane Transporters in Trypanosoma cruzi: Biological Function and Evaluation as Drug Targets. Curr Med Chem 2019; 26:6636-6651. [PMID: 31218951 DOI: 10.2174/0929867326666190620094710] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 12/12/2018] [Accepted: 02/04/2019] [Indexed: 01/19/2023]
Abstract
Amino acids and polyamines are involved in relevant processes for the parasite Trypanosoma cruzi, like protein synthesis, stress resistance, life cycle progression, infection establishment and redox balance, among others. In addition to the biosynthetic routes of amino acids, T. cruzi possesses transport systems that allow the active uptake from the extracellular medium; and in the case of polyamines, the uptake is the unique way to obtain these compounds. The TcAAAP protein family is absent in mammals and its members are responsible for amino acid and derivative uptake, thus the TcAAAP permeases are not only interesting and promising therapeutic targets but could also be used to direct the entry of toxic compounds into the parasite. Although there is a treatment available for Chagas disease, its limited efficacy in the chronic stage of the disease, as well as the side effects reported, highlight the urgent need to develop new therapies. Discovery of new drugs is a slow and cost-consuming process, and even during clinical trials the drugs can fail. In this context, drug repositioning is an interesting and recommended strategy by the World Health Organization since costs and time are significantly reduced. In this article, amino acids and polyamines transport and their potential as therapeutic targets will be revised, including examples of synthetic drugs and drug repurposing.
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Affiliation(s)
- Melisa Sayé
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Investigaciones Medicas A. Lanari, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Laboratorio de Parasitología Molecular, Buenos Aires, Argentina
| | - Chantal Reigada
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Investigaciones Medicas A. Lanari, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Laboratorio de Parasitología Molecular, Buenos Aires, Argentina
| | - Lucrecia Gauna
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Investigaciones Medicas A. Lanari, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Laboratorio de Parasitología Molecular, Buenos Aires, Argentina
| | - Edward A Valera-Vera
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Investigaciones Medicas A. Lanari, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Laboratorio de Parasitología Molecular, Buenos Aires, Argentina
| | - Claudio A Pereira
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Investigaciones Medicas A. Lanari, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Laboratorio de Parasitología Molecular, Buenos Aires, Argentina
| | - Mariana R Miranda
- Universidad de Buenos Aires, Facultad de Medicina, Instituto de Investigaciones Medicas A. Lanari, Buenos Aires, Argentina.,Consejo Nacional de Investigaciones Científicas y Técnicas, Universidad de Buenos Aires, Instituto de Investigaciones Médicas (IDIM), Laboratorio de Parasitología Molecular, Buenos Aires, Argentina
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12
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Wiczew D, Borowska A, Szkaradek K, Biegus T, Wozniak K, Pyclik M, Sitarska M, Jaszewski L, Radosinski L, Hanus-Lorenz B, Kraszewski S. Molecular mechanism of vSGLT inhibition by gneyulin reveals antiseptic properties against multidrug-resistant gram-negative bacteria. J Mol Model 2019; 25:186. [PMID: 31187300 DOI: 10.1007/s00894-019-4073-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 05/22/2019] [Indexed: 01/25/2023]
Abstract
Faced with the worldwide spread of multidrug-resistant (MDR) bacterial strains, together with a lack of any appropriate treatment, urgent steps to combat infectious diseases should be taken. Usually, bacterial components are studied to understand, by analogy, the functioning of human proteins. However, molecular data from bacteria gathered over the past decades provide a sound basis for the search for novel approaches in medical care. With this current work, we want to direct attention to inhibition of the vSGLT glucose transporter from Vibrio parahaemolyticus belonging to the sodium solute symporter (SSS) family, to block sugar transport into the bacterial cell and, as a consequence, to limit its growth. Potential bacteriostatic properties can be drawn from commercially available drugs developed for human diseases. This goal can also be reached with natural components from traditional herbal medicine. The presented data from the numerical analysis of 44 known inhibitors of sodium glucose symporters shed light on potential novel approaches in fighting Gram-negative multidrug-resistant microorganisms. Graphical abstract Molecular view on vSGLT channel inhibition by gneyulin B, the compound of natural origin.
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Affiliation(s)
- Daniel Wiczew
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Anna Borowska
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Kinga Szkaradek
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Tomasz Biegus
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Kamil Wozniak
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Marcelina Pyclik
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Magdalena Sitarska
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Lukasz Jaszewski
- Faculty of Chemistry, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Lukasz Radosinski
- Faculty of Chemistry, Division of Bioprocess and Biomedical Engineering, Wroclaw University of Science and Technology, Norwida 4/6, 50-370, Wroclaw, Poland
| | - Beata Hanus-Lorenz
- Faculty of Fundamental Problems of Technology, Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland
| | - Sebastian Kraszewski
- Faculty of Fundamental Problems of Technology, Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wybrzeze Wyspianskiego 27, 50-370, Wroclaw, Poland.
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13
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Buyuktimkin B, Zafar H, Saier MH. Comparative genomics of the transportome of Ten Treponema species. Microb Pathog 2019; 132:87-99. [PMID: 31029716 DOI: 10.1016/j.micpath.2019.04.034] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 04/02/2019] [Accepted: 04/23/2019] [Indexed: 02/08/2023]
Abstract
Treponema is a diverse bacterial genus, the species of which can be pathogenic, symbiotic, or free living. These treponemes can cause various diseases in humans and other animals, such as periodontal disease, bovine digital dermatitis and animal skin lesions. However, the most important and well-studied disease of treponemes that affects humans is 'syphilis'. This disease is caused by Treponema pallidum subspecie pallidum with 11-12 million new cases around the globe on an annual basis. In this study we analyze the transportome of ten Treponema species, with emphasis on the types of encoded transport proteins and their substrates. Of the ten species examined, two (T. primitia and T. azonutricium) reside as symbionts in the guts of termites; six (T. pallidum, T. paraluiscuniculi, T. pedis, T. denticola, T. putidum and T. brennaborense) are pathogens of either humans or animals, and T. caldarium and T. succinifaciens are avirulent species, the former being thermophilic. All ten species have a repertoire of transport proteins that assists them in residing in their respective ecological niches. For instance, oral pathogens use transport proteins that take up nutrients uniquely present in their ecosystem; they also encode multiple multidrug/macromolecule exporters that protect against antimicrobials and aid in biofilm formation. Proteins of termite gut symbionts convert cellulose into other sugars that can be metabolized by the host. As often observed for pathogens and symbionts, several of these treponemes have reduced genome sizes, and their small genomes correlate with their dependencies on the host. Overall, the transportomes of T. pallidum and other pathogens have a conglomerate of parasitic lifestyle-assisting proteins. For example, a T. pallidum repeat protein (TprK) mediates immune evasion; outer membrane proteins (OMPs) allow nutrient uptake and end product export, and several ABC transporters catalyze sugar uptake, considered pivotal to parasitic lifestyles. Taken together, the results of this study yield new information that may help open new avenues of treponeme research.
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Affiliation(s)
- Bora Buyuktimkin
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0116, USA
| | - Hassan Zafar
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0116, USA; Institute of Microbiology, University of Agriculture, Faisalabad, Punjab, Pakistan
| | - Milton H Saier
- Department of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA, 92093-0116, USA.
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14
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Iyer B, Rajkumar S. Genome sequence and comparative genomics of Rhizobium sp. Td3, a novel plant growth promoting phosphate solubilizing Cajanus cajan symbiont. Microbiol Res 2019; 218:32-40. [PMID: 30454656 DOI: 10.1016/j.micres.2018.09.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 08/21/2018] [Accepted: 09/21/2018] [Indexed: 11/18/2022]
Abstract
Rhizobium sp. Td3 is a Sesbania plant growth promoting, Cajanus cajan nodulating rhizobia. Studying its whole genome was important as it is a potent phosphate solubilizer with constitutive gluconic acid production ability through operation of the periplasmic glucose oxidation pathway even under conditions of catabolite repression. This is in contrast to the other explored phosphate solubilizers. Rhizobial isolates sequenced so far are known to lack components of the direct glucose oxidation pathway and cannot produce gluconic acid on its own. Here, we present the genome sequence of Rhizobium sp. Td3. Genome comprises of a single chromosome of size 5,606,547 bp (5.6 Mb) with no symbiotic plasmid. Rhizobium leguminosarum bv. viciae USDA2370 was the closest whole genome known. 109 genes responsible for diverse plant growth promoting activities like P solubilization, synthesis of acetoin, nitric oxide, indole-3 acetic acid, exopolysaccharide, siderophore and trehalose have been identified. Flagellar proteins, genes encoding antibiotic and metal resistance, enzymes required for combating oxidative stress as well as attachment and colonization in the plant rhizosphere are also present. Availability of genome sequence of such a versatile plant growth promoting agent will help in exploiting all the phyto-beneficial traits of Td3 for its use as a biofertilizer.
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Affiliation(s)
- Bhagya Iyer
- Institute of Science, Nirma University, Ahmedabad, 382 481, Gujarat, India
| | - Shalini Rajkumar
- Institute of Science, Nirma University, Ahmedabad, 382 481, Gujarat, India.
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15
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Khani A, Popp N, Kreikemeyer B, Patenge N. A Glycine Riboswitch in Streptococcus pyogenes Controls Expression of a Sodium:Alanine Symporter Family Protein Gene. Front Microbiol 2018. [PMID: 29527194 PMCID: PMC5829553 DOI: 10.3389/fmicb.2018.00200] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Regulatory RNAs play important roles in the control of bacterial gene expression. In this study, we investigated gene expression regulation by a putative glycine riboswitch located in the 5'-untranslated region of a sodium:alanine symporter family (SAF) protein gene in the group A Streptococcus pyogenes serotype M49 strain 591. Glycine-dependent gene expression mediated by riboswitch activity was studied using a luciferase reporter gene system. Maximal reporter gene expression was observed in the absence of glycine and in the presence of low glycine concentrations. Differences in glycine-dependent gene expression were not based on differential promoter activity. Expression of the SAF protein gene and the downstream putative cation efflux protein gene was investigated in wild-type bacteria by RT-qPCR transcript analyses. During growth in the presence of glycine (≥1 mM), expression of the genes were downregulated. Northern blot analyses revealed premature transcription termination in the presence of high glycine concentrations. Growth in the presence of 0.1 mM glycine led to the production of a full-length transcript. Furthermore, stability of the SAF protein gene transcript was drastically reduced in the presence of glycine. We conclude that the putative glycine riboswitch in S. pyogenes serotype M49 strain 591 represses expression of the SAF protein gene and the downstream putative cation efflux protein gene in the presence of high glycine concentrations. Sequence and secondary structure comparisons indicated that the streptococcal riboswitch belongs to the class of tandem aptamer glycine riboswitches.
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Affiliation(s)
- Afsaneh Khani
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
| | - Nicole Popp
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
| | - Bernd Kreikemeyer
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
| | - Nadja Patenge
- Institute of Medical Microbiology, Virology and Hygiene, University Medicine Rostock, Rostock, Germany
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16
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Chung VY, Turney BW. A Drosophila genetic model of nephrolithiasis: transcriptional changes in response to diet induced stone formation. BMC Urol 2017; 17:109. [PMID: 29183349 PMCID: PMC5706311 DOI: 10.1186/s12894-017-0292-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 10/30/2017] [Indexed: 02/07/2023] Open
Abstract
BACKGROUND Urolithiasis is a significant healthcare issue but the pathophysiology of stone disease remains poorly understood. Drosophila Malpighian tubules were known to share similar physiological function to human renal tubules. We have used Drosophila as a genetic model to study the transcriptional response to stone formation secondary to dietary manipulation. METHODS Wild-type male flies were raised on standard medium supplemented with lithogenic agents: control, sodium oxalate (NaOx) and ethylene glycol (EG). At 2 weeks, Malpighian tubules were dissected under polarized microscope to visualize crystals. The parallel group was dissected for RNA extraction and subsequent next-generation RNA sequencing. RESULTS Crystal formation was visualized in 20%(±2.2) of flies on control diet, 73%(±3.6) on NaOx diet and 84%(±2.2) on EG diet. Differentially expressed genes were identified in flies fed with NaOx and EG diet comparing with the control group. Fifty-eight genes were differentially expressed (FDR <0.05, p < 0.05) in NaOx diet and 20 genes in EG diet. The molecular function of differentially expressed genes were assessed. Among these, Nervana 3, Eaat1 (Excitatory amino acid transporter 1), CG7912, CG5404, CG3036 worked as ion transmembrane transporters, which were possibly involved in stone pathogenesis. CONCLUSIONS We have shown that by dietary modification, stone formation can be manipulated and visualized in Drosophila Malpighian tubules. This genetic model could be potentially used to identify the candidate genes that influence stone risk hence providing more insight to the pathogenesis of human stone disease.
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Affiliation(s)
- Vera Y. Chung
- Oxford Stone Group, Department of Urology, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
| | - Benjamin W. Turney
- Oxford Stone Group, Department of Urology, Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
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17
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Rong JC, Cha QQ, Ren XB, Xie BB, Song XY. Complete genome sequence of Pseudoalteromonas espejiana DSM9414 T, an amino-acid-requiring strain from seawater. Mar Genomics 2017; 38:21-23. [PMID: 28869183 DOI: 10.1016/j.margen.2017.08.006] [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: 07/29/2017] [Revised: 08/20/2017] [Accepted: 08/20/2017] [Indexed: 10/19/2022]
Abstract
Strain DSM9414, the type strain of Pseudoalteromonas espejiana, is a Gram-negative, and amino-acid-requiring stain isolated from seawater off the coast of Northern California. In this study, we report the complete genome sequence of Pseudoalteromonas espejiana DSM9414T. The genome (4,500,451bp; 40.3% G+C) is composed of two circular chromosomes: chromosome I is 3,720,756bp with 40.4% G+C content and chromosome II is 779,695bp with 39.8% G+C content. Genomic analysis showed that chromosome I encodes a complete set of ABC transporters responsible for branched-chain amino acids, whose homologous proteins were not discovered in other Pseudoalteromonas genomes released. This result indicated the tight dependence of extracellular amino acids for strain DSM9414T, which is consistent with its phenotype. The complete genome sequence of P. espejiana provides further genetic insights into the diversity of dependence on extracellular amino acids for Pseudoalteromonas species.
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Affiliation(s)
- Jin-Cheng Rong
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Qian-Qian Cha
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China
| | - Xue-Bing Ren
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China; Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Bin-Bin Xie
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China; Institute of Marine Science and Technology, Shandong University, Jinan 250100, China
| | - Xiao-Yan Song
- State Key Laboratory of Microbial Technology, Marine Biotechnology Research Center, Shandong University, Jinan 250100, China.
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18
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Lourenço J, Watkins ER, Obolski U, Peacock SJ, Morris C, Maiden MCJ, Gupta S. Lineage structure of Streptococcus pneumoniae may be driven by immune selection on the groEL heat-shock protein. Sci Rep 2017; 7:9023. [PMID: 28831154 PMCID: PMC5567354 DOI: 10.1038/s41598-017-08990-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2017] [Accepted: 07/20/2017] [Indexed: 12/29/2022] Open
Abstract
Populations of Streptococcus pneumoniae (SP) are typically structured into groups of closely related organisms or lineages, but it is not clear whether they are maintained by selection or neutral processes. Here, we attempt to address this question by applying a machine learning technique to SP whole genomes. Our results indicate that lineages evolved through immune selection on the groEL chaperone protein. The groEL protein is part of the groESL operon and enables a large range of proteins to fold correctly within the physical environment of the nasopharynx, thereby explaining why lineage structure is so stable within SP despite high levels of genetic transfer. SP is also antigenically diverse, exhibiting a variety of distinct capsular serotypes. Associations exist between lineage and capsular serotype but these can be easily perturbed, such as by vaccination. Overall, our analyses indicate that the evolution of SP can be conceptualized as the rearrangement of modular functional units occurring on several different timescales under different pressures: some patterns have locked in early (such as the epistatic interactions between groESL and a constellation of other genes) and preserve the differentiation of lineages, while others (such as the associations between capsular serotype and lineage) remain in continuous flux.
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Affiliation(s)
- José Lourenço
- Department of Zoology, University of Oxford, Oxford, United Kingdom.
| | | | - Uri Obolski
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | - Samuel J Peacock
- Department of Zoology, University of Oxford, Oxford, United Kingdom
| | | | | | - Sunetra Gupta
- Department of Zoology, University of Oxford, Oxford, United Kingdom
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19
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Samadi R, Shafiei B, Azizi F, Ghasemi A. Radioactive Iodine Therapy and Glucose Tolerance. CELL JOURNAL 2017; 19:184-193. [PMID: 28670511 PMCID: PMC5413587 DOI: 10.22074/cellj.2016.4251] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 07/19/2016] [Indexed: 11/09/2022]
Abstract
Radioactive iodine therapy is commonly used as an adjuvant therapy in follicular and
papillary thyroid carcinoma (PTC) and in the treatment of Graves’ disease (GD). The
basis of this therapy is the accumulation of radioactive iodine by the sodium-iodide
symporter (NIS) in the thyroid gland. Expression of NIS by extrathyroidal tissues such
as islets of pancreas has been reported. Radioactive iodine uptake by pancreatic
beta-cells can potentially damage these cells. In this study, we discuss the possible
associations between radioactive iodine and glucose intolerance. Overall, radioactive
iodine uptake by the pancreas may damage beta-cells and predispose patients to
glucose intolerance or type 2 diabetes, particularly in patients exposed to radioactive
iodine therapy following total thyroidectomy. Further studies are needed to clarify and
confirm this association.
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Affiliation(s)
- Roghaieh Samadi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Babak Shafiei
- Department of Nuclear Medicine, Taleghani Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Fereidoun Azizi
- Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Asghar Ghasemi
- Endocrine Physiology Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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20
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Fuhrer T, Zampieri M, Sévin DC, Sauer U, Zamboni N. Genomewide landscape of gene-metabolome associations in Escherichia coli. Mol Syst Biol 2017; 13:907. [PMID: 28093455 PMCID: PMC5293155 DOI: 10.15252/msb.20167150] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Metabolism is one of the best-understood cellular processes whose network topology of enzymatic reactions is determined by an organism's genome. The influence of genes on metabolite levels, however, remains largely unknown, particularly for the many genes encoding non-enzymatic proteins. Serendipitously, genomewide association studies explore the relationship between genetic variants and metabolite levels, but a comprehensive interaction network has remained elusive even for the simplest single-celled organisms. Here, we systematically mapped the association between > 3,800 single-gene deletions in the bacterium Escherichia coli and relative concentrations of > 7,000 intracellular metabolite ions. Beyond expected metabolic changes in the proximity to abolished enzyme activities, the association map reveals a largely unknown landscape of gene-metabolite interactions that are not represented in metabolic models. Therefore, the map provides a unique resource for assessing the genetic basis of metabolic changes and conversely hypothesizing metabolic consequences of genetic alterations. We illustrate this by predicting metabolism-related functions of 72 so far not annotated genes and by identifying key genes mediating the cellular response to environmental perturbations.
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Affiliation(s)
- Tobias Fuhrer
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Mattia Zampieri
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel C Sévin
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Uwe Sauer
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Nicola Zamboni
- Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
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21
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Bracher S, Schmidt CC, Dittmer SI, Jung H. Core Transmembrane Domain 6 Plays a Pivotal Role in the Transport Cycle of the Sodium/Proline Symporter PutP. J Biol Chem 2016; 291:26208-26215. [PMID: 27793991 DOI: 10.1074/jbc.m116.753103] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 10/12/2016] [Indexed: 12/21/2022] Open
Abstract
Crystal structures of transporters with a LeuT-type structural fold assign core transmembrane domain 6 (TM6') a central role in substrate binding and translocation. Here, the function of TM6' in the sodium/proline symporter PutP, a member of the solute/sodium symporter family, was investigated. A complete scan of TM6' identified eight amino acids as particularly important for PutP function. Of these residues, Tyr-248, His-253, and Arg-257 impact sodium binding, whereas Arg-257 and Ala-260 may participate in interactions leading to closure of the inner gate. Furthermore, the previous suggestion of an involvement of Trp-244, Tyr-248, and Pro-252 in proline binding is further supported. In addition, substitution of Gly-245, Gly-247, and Gly-250 affects the amount of PutP in the membrane. A Cys accessibility analysis suggests an involvement of the inner half of TM6' in the formation of a hydrophilic pathway that is open to the inside in the absence of ligands and closed in the presence of sodium and proline. In conclusion, the results demonstrate that TM6' plays a central role in substrate binding and release on the inner side of the membrane also in PutP and extend the knowledge on functionally relevant amino acids in transporters with a LeuT-type structural fold.
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Affiliation(s)
- Susanne Bracher
- From the Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152 Martinsried, Germany
| | - Claudia C Schmidt
- From the Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152 Martinsried, Germany
| | - Sophie I Dittmer
- From the Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152 Martinsried, Germany
| | - Heinrich Jung
- From the Division of Microbiology, Department of Biology 1, Ludwig Maximilians University Munich, D-82152 Martinsried, Germany
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22
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Tang X, Liu H, Chen Q, Wang X, Xiong Y, Zhao P. Genome-Wide Identification, Characterization and Expression Analysis of the Solute Carrier 6 Gene Family in Silkworm (Bombyx mori). Int J Mol Sci 2016; 17:ijms17101675. [PMID: 27706106 PMCID: PMC5085708 DOI: 10.3390/ijms17101675] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Accepted: 09/26/2016] [Indexed: 11/16/2022] Open
Abstract
The solute carrier 6 (SLC6) gene family, initially known as the neurotransmitter transporters, plays vital roles in the regulation of neurotransmitter signaling, nutrient absorption and motor behavior. In this study, a total of 16 candidate genes were identified as SLC6 family gene homologs in the silkworm (Bombyx mori) genome. Spatio-temporal expression patterns of silkworm SLC6 gene transcripts indicated that these genes were highly and specifically expressed in midgut, brain and gonads; moreover, these genes were expressed primarily at the feeding stage or adult stage. Levels of expression for most midgut-specific and midgut-enriched gene transcripts were down-regulated after starvation but up-regulated after re-feeding. In addition, we observed that expression levels of these genes except for BmSLC6-15 and BmGT1 were markedly up-regulated by a juvenile hormone analog. Moreover, brain-enriched genes showed differential expression patterns during wandering and mating processes, suggesting that these genes may be involved in modulating wandering and mating behaviors. Our results improve our understanding of the expression patterns and potential physiological functions of the SLC6 gene family, and provide valuable information for the comprehensive functional analysis of the SLC6 gene family.
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Affiliation(s)
- Xin Tang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
| | - Huawei Liu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
| | - Quanmei Chen
- Department of Biochemistry and Molecular Biology, Chongqing Medical University, Chongqing 400016, China.
| | - Xin Wang
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
- Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing 400715, China.
| | - Ying Xiong
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
| | - Ping Zhao
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing 400715, China.
- Chongqing Engineering and Technology Research Center for Novel Silk Materials, Chongqing 400715, China.
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Borghese R, Canducci L, Musiani F, Cappelletti M, Ciurli S, Turner RJ, Zannoni D. On the role of a specific insert in acetate permeases (ActP) for tellurite uptake in bacteria: Functional and structural studies. J Inorg Biochem 2016; 163:103-109. [PMID: 27421695 DOI: 10.1016/j.jinorgbio.2016.06.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2016] [Revised: 06/14/2016] [Accepted: 06/23/2016] [Indexed: 11/17/2022]
Abstract
The oxyanion tellurite (TeO32-) is extremely toxic to bacterial cells. In Rhodobacter capsulatus, tellurite enters the cytosol by means of the high uptake-rate acetate permease RcActP2, encoded by one of the three actP genes present in this species (actP1, actP2 and actP3). Conversely, in Escherichia coli a low rate influx of the oxyanion is measured, which depends mainly on the phosphate transporter EcPitA, even though E. coli contains its own EcActP acetate permease. Here we report that when the actP2 gene from R. capsulatus is expressed in wild-type E. coli HB101 and in E. coli JW3460 ΔpitA mutant, the cellular intake of tellurite increases up to four times, suggesting intrinsic structural differences between EcActP and RcActP2. Indeed, a sequence analysis indicated the presence in RcActP2 of an insert of 15-16 residues, located between trans-membrane (TM) helices 6 and 7, which is absent in both EcActP and RcActP1. Based on this observation, the molecular models of homodimeric RcActP1 and RcActP2 were calculated and analyzed. In the RcActP2 model, the insert induces a perturbation in the conformation of the loop between TM helices 6 and 7, located at the RcActP2 dimerization interface. This perturbation opens a cavity on the periplasmic side that is closed, instead, in the RcActP1 model. This cavity also features an increase of the positive electric potential on the protein surface, an effect ascribed to specific residues Lys261, Lys281 and Arg560. We propose that this positively charged patch in RcActP2 is involved in recognition and translocation of the TeO32- anion, attributing to RcActP2 a greater ability as compared to RcActP1 to transport this inorganic poison inside the cells.
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Affiliation(s)
- Roberto Borghese
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy.
| | - Laura Canducci
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Francesco Musiani
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Martina Cappelletti
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Stefano Ciurli
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Raymond J Turner
- Department of Biological Sciences, University of Calgary, Calgary, Canada
| | - Davide Zannoni
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
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24
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Ortiga-Carvalho TM, Chiamolera MI, Pazos-Moura CC, Wondisford FE. Hypothalamus-Pituitary-Thyroid Axis. Compr Physiol 2016; 6:1387-428. [PMID: 27347897 DOI: 10.1002/cphy.c150027] [Citation(s) in RCA: 214] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The hypothalamus-pituitary-thyroid (HPT) axis determines the set point of thyroid hormone (TH) production. Hypothalamic thyrotropin-releasing hormone (TRH) stimulates the synthesis and secretion of pituitary thyrotropin (thyroid-stimulating hormone, TSH), which acts at the thyroid to stimulate all steps of TH biosynthesis and secretion. The THs thyroxine (T4) and triiodothyronine (T3) control the secretion of TRH and TSH by negative feedback to maintain physiological levels of the main hormones of the HPT axis. Reduction of circulating TH levels due to primary thyroid failure results in increased TRH and TSH production, whereas the opposite occurs when circulating THs are in excess. Other neural, humoral, and local factors modulate the HPT axis and, in specific situations, determine alterations in the physiological function of the axis. The roles of THs are vital to nervous system development, linear growth, energetic metabolism, and thermogenesis. THs also regulate the hepatic metabolism of nutrients, fluid balance and the cardiovascular system. In cells, TH actions are mediated mainly by nuclear TH receptors (210), which modify gene expression. T3 is the preferred ligand of THR, whereas T4, the serum concentration of which is 100-fold higher than that of T3, undergoes extra-thyroidal conversion to T3. This conversion is catalyzed by 5'-deiodinases (D1 and D2), which are TH-activating enzymes. T4 can also be inactivated by conversion to reverse T3, which has very low affinity for THR, by 5-deiodinase (D3). The regulation of deiodinases, particularly D2, and TH transporters at the cell membrane control T3 availability, which is fundamental for TH action. © 2016 American Physiological Society. Compr Physiol 6:1387-1428, 2016.
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Affiliation(s)
- Tania M Ortiga-Carvalho
- Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | - Maria I Chiamolera
- Department of Medicine, Escola Paulista de Medicina, Universidade Federal de Sao Paulo, Sao Paulo, Brazil
| | - Carmen C Pazos-Moura
- Institute of Biophysics Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, UFRJ, Rio de Janeiro, Brazil
| | - Fredic E Wondisford
- Department of Medicine, Rutgers-Robert Wood Johnson Medical School, New Brunswick, New Jersey, USA
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25
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Membrane transporters studied by EPR spectroscopy: structure determination and elucidation of functional dynamics. Biochem Soc Trans 2016; 44:905-15. [DOI: 10.1042/bst20160024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Indexed: 12/19/2022]
Abstract
During their mechanistic cycles membrane transporters often undergo extensive conformational changes, sampling a range of orientations, in order to complete their function. Such membrane transporters present somewhat of a challenge to conventional structural studies; indeed, crystallization of membrane-associated proteins sometimes require conditions that vary vastly from their native environments. Moreover, this technique currently only allows for visualization of single selected conformations during any one experiment. EPR spectroscopy is a magnetic resonance technique that offers a unique opportunity to study structural, environmental and dynamic properties of such proteins in their native membrane environments, as well as readily sampling their substrate-binding-induced dynamic conformational changes especially through complementary computational analyses. Here we present a review of recent studies that utilize a variety of EPR techniques in order to investigate both the structure and dynamics of a range of membrane transporters and associated proteins, focusing on both primary (ABC-type transporters) and secondary active transporters which were key interest areas of the late Professor Stephen Baldwin to whom this review is dedicated.
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26
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Schwan WR, Wetzel KJ. Osmolyte transport in Staphylococcus aureus and the role in pathogenesis. World J Clin Infect Dis 2016; 6:22-27. [PMID: 27429907 PMCID: PMC4943863 DOI: 10.5495/wjcid.v6.i2.22] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2015] [Revised: 02/18/2016] [Accepted: 04/11/2016] [Indexed: 02/06/2023] Open
Abstract
Osmolyte transport is a pivotal part of bacterial life, particularly in high salt environments. Several low and high affinity osmolyte transport systems have been identified in various bacterial species. A lot of research has centered on characterizing the osmolyte transport systems of Gram-negative bacteria, but less has been done to characterize the same transport systems in Gram-positive bacteria. This review will focus on the previous work that has been done to understand the osmolyte transport systems in the species Staphylococcus aureus and how these transporters may serve dual functions in allowing the bacteria to survive and grow in a variety of environments, including on the surface or within humans or other animals.
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27
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Bualuang A, Kageyama H, Tanaka Y, Incharoensakdi A, Takabe T. Functional characterization of a member of alanine or glycine: cation symporter family in halotolerant cyanobacterium Aphanothece halophytica. Biosci Biotechnol Biochem 2015; 79:230-5. [DOI: 10.1080/09168451.2014.968091] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Abstract
Membrane proteins of amino acid–polyamine–organocation (APC) superfamily transport amino acids and amines across membranes and play important roles in the regulation of cellular processes. The alanine or glycine: cation symporter (AGCS) family belongs to APC superfamily and is found in prokaryotes, but its substrate specificity remains to be clarified. In this study, we found that a halotolerant cyanobacterium, Aphanothece halophytica has two putative ApagcS genes. The deduced amino acid sequence of one of genes, ApagcS1, exhibited high homology to Pseudomonas AgcS. The ApagcS1 gene was expressed in Escherichia coli JW4166 which is deficient in glycine uptake. Kinetics studies in JW4166 revealed that ApAgcS1 is a sodium-dependent glycine transporter. Competition experiments showed the significant inhibition by glutamine, asparagine, and glycine. The level of mRNA for ApagcS1 was induced by NaCl and nitrogen-deficient stresses. Uptake of glutamine by ApAgcS1 was also observed. Based on these data, the physiological role of ApAgcS1 was discussed.
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Affiliation(s)
- Aporn Bualuang
- Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Japan
- Faculty of Science, Department of Biochemistry, Chulalongkorn University, Bangkok, Thailand
| | - Hakuto Kageyama
- Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Japan
| | - Yoshito Tanaka
- Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Japan
| | - Aran Incharoensakdi
- Faculty of Science, Department of Biochemistry, Chulalongkorn University, Bangkok, Thailand
| | - Teruhiro Takabe
- Graduate School of Environmental and Human Sciences, Meijo University, Nagoya, Japan
- Research Institute of Meijo University, Nagoya, Japan
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Martínez-Quintana JA, Peregrino-Uriarte AB, Gollas-Galván T, Gómez-Jiménez S, Yepiz-Plascencia G. The glucose transporter 1 -GLUT1- from the white shrimp Litopenaeus vannamei is up-regulated during hypoxia. Mol Biol Rep 2014; 41:7885-98. [PMID: 25167855 DOI: 10.1007/s11033-014-3682-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 08/19/2014] [Indexed: 11/29/2022]
Abstract
During hypoxia the shrimp Litopenaeus vannamei accelerates anaerobic glycolysis to obtain energy; therefore, a correct supply of glucose to the cells is needed. Facilitated glucose transport across the cells is mediated by a group of membrane embedded integral proteins called GLUT; being GLUT1 the most ubiquitous form. In this work, we report the first cDNA nucleotide and deduced amino acid sequences of a glucose transporter 1 from L. vannamei. A 1619 bp sequence was obtained by RT-PCR and RACE approaches. The 5´ UTR is 161 bp and the poly A tail is exactly after the stop codon in the mRNA. The ORF is 1485 bp and codes for 485 amino acids. The deduced protein sequence has high identity to GLUT1 proteins from several species and contains all the main features of glucose transporter proteins, including twelve transmembrane domains, the conserved motives and amino acids involved in transport activity, ligands binding and membrane anchor. Therefore, we decided to name this sequence, glucose transporter 1 of L. vannamei (LvGLUT1). A partial gene sequence of 8.87 Kbp was also obtained; it contains the complete coding sequence divided in 10 exons. LvGlut1 expression was detected in hemocytes, hepatopancreas, intestine gills, muscle and pleopods. The higher relative expression was found in gills and the lower in hemocytes. This indicates that LvGlut1 is ubiquitously expressed but its levels are tissue-specific and upon short-term hypoxia, the GLUT1 transcripts increase 3.7-fold in hepatopancreas and gills. To our knowledge, this is the first evidence of expression of GLUT1 in crustaceans.
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Affiliation(s)
- José A Martínez-Quintana
- Centro de Investigación en Alimentación y Desarrollo. A.C, P.O. Box 1735, Carretera a Ejido La Victoria Km. 0.6, 83304, Hermosillo, Sonora, Mexico
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29
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Zanin L, Tomasi N, Wirdnam C, Meier S, Komarova NY, Mimmo T, Cesco S, Rentsch D, Pinton R. Isolation and functional characterization of a high affinity urea transporter from roots of Zea mays. BMC PLANT BIOLOGY 2014; 14:222. [PMID: 25168432 PMCID: PMC4160556 DOI: 10.1186/s12870-014-0222-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Accepted: 08/06/2014] [Indexed: 05/24/2023]
Abstract
BACKGROUND Despite its extensive use as a nitrogen fertilizer, the role of urea as a directly accessible nitrogen source for crop plants is still poorly understood. So far, the physiological and molecular aspects of urea acquisition have been investigated only in few plant species highlighting the importance of a high-affinity transport system. With respect to maize, a worldwide-cultivated crop requiring high amounts of nitrogen fertilizer, the mechanisms involved in the transport of urea have not yet been identified. The aim of the present work was to characterize the high-affinity urea transport system in maize roots and to identify the high affinity urea transporter. RESULTS Kinetic characterization of urea uptake (<300 μM) demonstrated the presence in maize roots of a high-affinity and saturable transport system; this system is inducible by urea itself showing higher Vmax and Km upon induction. At molecular level, the ORF sequence coding for the urea transporter, ZmDUR3, was isolated and functionally characterized using different heterologous systems: a dur3 yeast mutant strain, tobacco protoplasts and a dur3 Arabidopsis mutant. The expression of the isolated sequence, ZmDUR3-ORF, in dur3 yeast mutant demonstrated the ability of the encoded protein to mediate urea uptake into cells. The subcellular targeting of DUR3/GFP fusion proteins in tobacco protoplasts gave results comparable to the localization of the orthologous transporters of Arabidopsis and rice, suggesting a partial localization at the plasma membrane. Moreover, the overexpression of ZmDUR3 in the atdur3-3 Arabidopsis mutant showed to complement the phenotype, since different ZmDUR3-overexpressing lines showed either comparable or enhanced 15[N]-urea influx than wild-type plants. These data provide a clear evidence in planta for a role of ZmDUR3 in urea acquisition from an extra-radical solution. CONCLUSIONS This work highlights the capability of maize plants to take up urea via an inducible and high-affinity transport system. ZmDUR3 is a high-affinity urea transporter mediating the uptake of this molecule into roots. Data may provide a key to better understand the mechanisms involved in urea acquisition and contribute to deepen the knowledge on the overall nitrogen-use efficiency in crop plants.
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Affiliation(s)
- Laura Zanin
- />Dipartimento di Scienze Agrarie e Ambientali, University of Udine, via delle Scienze 208, I-33100 Udine, Italy
| | - Nicola Tomasi
- />Dipartimento di Scienze Agrarie e Ambientali, University of Udine, via delle Scienze 208, I-33100 Udine, Italy
| | - Corina Wirdnam
- />Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Stefan Meier
- />Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Nataliya Y Komarova
- />Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Tanja Mimmo
- />Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, I-39100 Bolzano, Italy
| | - Stefano Cesco
- />Faculty of Science and Technology, Free University of Bolzano, Piazza Università 5, I-39100 Bolzano, Italy
| | - Doris Rentsch
- />Institute of Plant Sciences, University of Bern, Altenbergrain 21, CH-3013 Bern, Switzerland
| | - Roberto Pinton
- />Dipartimento di Scienze Agrarie e Ambientali, University of Udine, via delle Scienze 208, I-33100 Udine, Italy
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Vastermark A, Wollwage S, Houle ME, Rio R, Saier MH. Expansion of the APC superfamily of secondary carriers. Proteins 2014; 82:2797-811. [PMID: 25043943 DOI: 10.1002/prot.24643] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/16/2014] [Accepted: 06/26/2014] [Indexed: 11/07/2022]
Abstract
The amino acid-polyamine-organoCation (APC) superfamily is the second largest superfamily of secondary carriers currently known. In this study, we establish homology between previously recognized APC superfamily members and proteins of seven new families. These families include the PAAP (Putative Amino Acid Permease), LIVCS (Branched Chain Amino Acid:Cation Symporter), NRAMP (Natural Resistance-Associated Macrophage Protein), CstA (Carbon starvation A protein), KUP (K⁺ Uptake Permease), BenE (Benzoate:H⁺ Virginia Symporter), and AE (Anion Exchanger). The topology of the well-characterized human Anion Exchanger 1 (AE1) conforms to a UraA-like topology of 14 TMSs (12 α-helical TMSs and 2 mixed coil/helical TMSs). All functionally characterized members of the APC superfamily use cation symport for substrate accumulation except for some members of the AE family which frequently use anion:anion exchange. We show how the different topologies fit into the framework of the common LeuT-like fold, defined earlier (Proteins. 2014 Feb;82(2):336-46), and determine that some of the new members contain previously undocumented topological variations. All new entries contain the two 5 or 7 TMS APC superfamily repeat units, sometimes with extra TMSs at the ends, the variations being greatest within the CstA family. New, functionally characterized members transport amino acids, peptides, and inorganic anions or cations. Except for anions, these are typical substrates of established APC superfamily members. Active site TMSs are rich in glycyl residues in variable but conserved constellations. This work expands the APC superfamily and our understanding of its topological variations.
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Affiliation(s)
- Ake Vastermark
- Department of Molecular Biology, University of California at San Diego, La Jolla, California, 92093-0116
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31
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Laehnemann D, Peña-Miller R, Rosenstiel P, Beardmore R, Jansen G, Schulenburg H. Genomics of rapid adaptation to antibiotics: convergent evolution and scalable sequence amplification. Genome Biol Evol 2014; 6:1287-301. [PMID: 24850796 PMCID: PMC4079197 DOI: 10.1093/gbe/evu106] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Evolutionary adaptation can be extremely fast, especially in response to high selection intensities. A prime example is the surge of antibiotic resistance in bacteria. The genomic underpinnings of such rapid changes may provide information on the genetic processes that enhance fast responses and the particular trait functions under selection. Here, we use experimentally evolved Escherichia coli for a detailed dissection of the genomics of rapid antibiotic resistance evolution. Our new analyses demonstrate that amplification of a sequence region containing several known antibiotic resistance genes represents a fast genomic response mechanism under high antibiotic stress, here exerted by drug combination. In particular, higher dosage of such antibiotic combinations coincided with higher copy number of the sequence region. The amplification appears to be evolutionarily costly, because amplification levels rapidly dropped after removal of the drugs. Our results suggest that amplification is a scalable process, as copy number rapidly changes in response to the selective pressure encountered. Moreover, repeated patterns of convergent evolution were found across the experimentally evolved bacterial populations, including those with lower antibiotic selection intensities. Intriguingly, convergent evolution was identified on different organizational levels, ranging from the above sequence amplification, high variant frequencies in specific genes, prevalence of individual nonsynonymous mutations to the unusual repeated occurrence of a particular synonymous mutation in Glycine codons. We conclude that constrained evolutionary trajectories underlie rapid adaptation to antibiotics. Of the identified genomic changes, sequence amplification seems to represent the most potent, albeit costly genomic response mechanism to high antibiotic stress.
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Affiliation(s)
- David Laehnemann
- Department of Evolutionary Ecology and Genetics, University of Kiel, Germany
| | - Rafael Peña-Miller
- Biosciences, Geoffrey Pope Building, University of Exeter, United KingdomDepartment of Zoology, University of Oxford, United Kingdom
| | - Philip Rosenstiel
- Institute for Clinical Molecular Biology, University of Kiel, Germany
| | - Robert Beardmore
- Biosciences, Geoffrey Pope Building, University of Exeter, United Kingdom
| | - Gunther Jansen
- Department of Evolutionary Ecology and Genetics, University of Kiel, Germany
| | - Hinrich Schulenburg
- Department of Evolutionary Ecology and Genetics, University of Kiel, Germany
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Darrouzet E, Lindenthal S, Marcellin D, Pellequer JL, Pourcher T. The sodium/iodide symporter: state of the art of its molecular characterization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:244-53. [PMID: 23988430 DOI: 10.1016/j.bbamem.2013.08.013] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2013] [Revised: 08/05/2013] [Accepted: 08/19/2013] [Indexed: 12/30/2022]
Abstract
The sodium/iodide symporter (NIS or SLC5A5) is an intrinsic membrane protein implicated in iodide uptake into thyroid follicular cells. It plays a crucial role in iodine metabolism and thyroid regulation and its function is widely exploited in the diagnosis and treatment of benign and malignant thyroid diseases. A great effort is currently being made to develop a NIS-based gene therapy also allowing the radiotreatment of nonthyroidal tumors. NIS is also expressed in other tissues, such as salivary gland, stomach and mammary gland during lactation, where its physiological role remains unclear. The molecular identity of the thyroid iodide transporter was elucidated approximately fifteen years ago. It belongs to the superfamily of sodium/solute symporters, SSS (and to the human transporter family, SLC5), and is composed of 13 transmembrane helices and 643 amino acid residues in humans. Knowledge concerning NIS structure/function relationship has been obtained by taking advantage of the high resolution structure of one member of the SSS family, the Vibrio parahaemolyticus sodium/galactose symporter (vSGLT), and from studies of gene mutations leading to congenital iodine transport defects (ITD). This review will summarize current knowledge regarding the molecular characterization of NIS.
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Affiliation(s)
- Elisabeth Darrouzet
- SBTN, bât 170, centre de Marcoule, BP 17171, 30207 Bagnols sur Cèze CEDEX, France; Laboratoire TIRO, Faculté de médecine, Université de Nice Sophia-Antipolis, 28 Avenue de Valombrose, 06107 Nice CEDEX, France; CAL, TIRO, F-06107 Nice, France.
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Jarończyk M, Wołosewicz K, Gabrielsen M, Nowak G, Kufareva I, Mazurek AP, Ravna AW, Abagyan R, Bojarski AJ, Sylte I, Chilmonczyk Z. Synthesis, in vitro binding studies and docking of long-chain arylpiperazine nitroquipazine analogues, as potential serotonin transporter inhibitors. Eur J Med Chem 2012; 49:200-10. [PMID: 22309909 DOI: 10.1016/j.ejmech.2012.01.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2011] [Revised: 01/05/2012] [Accepted: 01/06/2012] [Indexed: 11/28/2022]
Abstract
It is well known that 6-nitroquipazine exhibits about 150-fold higher affinity for the serotonin transporter (SERT) than quipazine and recently we showed quipazine buspirone analogues with high to moderate SERT affinity. Now we have designed and synthesized several 6-nitroquipazine buspirone derivatives. Unexpectedly, their SERT binding affinities were moderate, and much lower than that of the previously studied quipazine buspirone analogues. To explain these findings, docking studies of both groups of compounds into two different homology models of human SERT was performed using a flexible target-ligand docking approach (4D docking). The crystal structures of leucine transporter from Aquifex aeolicus in complex with leucine and with tryptophan were used as templates for the SERT models in closed and outward-facing conformations, respectively. We found that the latter conformation represents the most reliable model for binding of buspirone analogues. Docking into that model showed that the nitrated compounds acquire a rod like shape in the binding pocket with polar groups (nitro- and imido-) at the ends of the rod. 6-Nitro substituents gave steric clashes with amino acids located at the extracellular loop 4, which may explain their lower affinity than corresponding quipazine buspirone analogues. The results from the present study may suggest chemical design strategies to improve the SERT modulators.
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Witowska-Jarosz J, Jarończyk M, Mazurek AP, Sylte I, Bojarski AJ, Chilmonczyk Z, Jarosz M. Mass-spectrometric studies of new 6-nitroquipazines—serotonin transporter inhibitors. Anal Bioanal Chem 2012; 402:537-41. [PMID: 21960253 PMCID: PMC3249537 DOI: 10.1007/s00216-011-5410-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2011] [Revised: 08/24/2011] [Accepted: 09/08/2011] [Indexed: 11/27/2022]
Abstract
Six synthesized 6-nitroquipazine derivatives were examined by electron ionization (EI) and electrospray ionization (ESI) mass spectrometry in positive and negative ion mode. The compounds exhibit high affinity for the serotonin transporter (SERT) and belong to a new class of SERT inhibitors. The EI mass spectra registered in negative ion mode showed prominent molecular ions for all the compounds studied. All EI mass spectra and all ESI mass spectra showed similar fragmentation pathways of molecular ions, but the pathways differed between EI and ESI. The differences were explained with the aid of theoretical evaluation of the stability of the respective radical ions (EI MS) and protonated ions (ESI MS). Alkylnitroquipazines in SERT binding pocket superimposed on an exemplary MS fragmentation pattern ![]()
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Affiliation(s)
| | | | | | - Ingebrigt Sylte
- Medical Pharmacology and Toxicology, Department of Medical Biology, Faculty of Health Sciences, University of Tromsø, 9037 Tromsø, Norway
| | - Andrzej J. Bojarski
- Department of Medicinal Chemistry, Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Cracow, Poland
| | | | - Maciej Jarosz
- Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland
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Denger K, Lehmann S, Cook AM. Molecular genetics and biochemistry of N-acetyltaurine degradation by Cupriavidus necator H16. MICROBIOLOGY-SGM 2011; 157:2983-2991. [PMID: 21757489 DOI: 10.1099/mic.0.048462-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Cupriavidus necator H16 (DSM 428), whose genome has been sequenced, was found to degrade N-acetyltaurine as a sole source of carbon and energy for growth. Utilization of the compound was quantitative. The degradative pathway involved an inducible N-acetyltaurine amidohydrolase (NaaS), which catalysed the cleavage of N-acetyltaurine to acetate and taurine. The degradation of the latter compound is via an inducible, degradative pathway that involves taurine dehydrogenase [EC 1.4.2.-], sulfoacetaldehyde acetyltransferase [EC 2.3.3.15], phosphotransacetylase [EC 2.4.1.8], a sulfite exporter [TC 9.A.29.2.1] and sulfite dehydrogenase [EC 1.8.2.1]. Induction of the expression of representative gene products, encoded by at least four gene clusters, was confirmed biochemically. The acetate released by NaaS was activated to acetyl-CoA by an inducible acetate-CoA ligase [EC 6.2.1.1]. NaaS was purified to homogeneity; it had a K(m) value of 9.4 mM for N-acetyltaurine, and it contained tightly bound Zn and Fe atoms. The denatured enzyme has a molecular mass of about 61 kDa (determined by SDS-PAGE) and the native enzyme was apparently monomeric. Peptide-mass fingerprinting identified the locus tag as H16_B0868 in a five-gene cluster, naaROPST (H16_B0865-H16_B0869). The cluster presumably encodes a LysR-type transcriptional regulator (NaaR), a membrane protein (NaaO), a solute : sodium symporter-family permease [TC 2.A.21] (NaaP), the metal-dependent amidohydrolase (NaaS) and a putative metallochaperone (COG0523) (NaaT). Reverse-transcription PCR indicated that naaOPST were inducibly transcribed.
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Affiliation(s)
- Karin Denger
- Department of Biology, The University, D-78457 Konstanz, Germany
| | - Sabine Lehmann
- Department of Biology, The University, D-78457 Konstanz, Germany
| | - Alasdair M Cook
- Department of Biology, The University, D-78457 Konstanz, Germany
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Amin A, Ando T, Saijo S, Yamato I. Role of Asp187 and Gln190 in the Na+/proline symporter (PutP) of Escherichia coli. J Biochem 2011; 150:395-402. [PMID: 21586535 DOI: 10.1093/jb/mvr062] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Asp187 and Gln190 were predicted as conserved and closely located at the Na(+) binding site in a topology and homology model structure of Na(+)/proline symporter (PutP) of Escherichia coli. The replacement of Asp187 with Ala or Leu did not affect proline transport activity; whereas, change to Gln abolished the active transport. The binding affinity for Na(+) or proline of these mutants was similar to that of wild-type (WT) PutP. This result indicates Asp187 to be responsible for active transport of proline without affecting the binding. Replacement of Gln190 with Ala, Asn, Asp, Leu and Glu had no effect on transport or binding, suggesting that it may not have a role in the transport. However, in the negative D187Q mutant, a second mutation, of Gln190 to Glu or Leu, restored 46 or 7% of the transport activity of WT, respectively, while mutation to Ala, Asn or Asp had no effect. Thus, side chain at position 190 has a crucial role in suppressing the functional defect of the D187Q mutant. We conclude that Asp187 is responsible for transport activity instead of coupling-ion binding by constituting the translocation pathway of the ion and Gln190 provides a suppressing mutation site to regain PutP functional activity.
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Affiliation(s)
- Anowarul Amin
- Department of Biological Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba 278-8510, Japan
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Pilalis E, Chatziioannou AA, Grigoroudis AI, Panagiotidis CA, Kolisis FN, Kyriakidis DA. Escherichia coli genome-wide promoter analysis: identification of additional AtoC binding target elements. BMC Genomics 2011; 12:238. [PMID: 21569465 PMCID: PMC3118216 DOI: 10.1186/1471-2164-12-238] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2010] [Accepted: 05/13/2011] [Indexed: 11/16/2022] Open
Abstract
Background Studies on bacterial signal transduction systems have revealed complex networks of functional interactions, where the response regulators play a pivotal role. The AtoSC system of E. coli activates the expression of atoDAEB operon genes, and the subsequent catabolism of short-chain fatty acids, upon acetoacetate induction. Transcriptome and phenotypic analyses suggested that atoSC is also involved in several other cellular activities, although we have recently reported a palindromic repeat within the atoDAEB promoter as the single, cis-regulatory binding site of the AtoC response regulator. In this work, we used a computational approach to explore the presence of yet unidentified AtoC binding sites within other parts of the E. coli genome. Results Through the implementation of a computational de novo motif detection workflow, a set of candidate motifs was generated, representing putative AtoC binding targets within the E. coli genome. In order to assess the biological relevance of the motifs and to select for experimental validation of those sequences related robustly with distinct cellular functions, we implemented a novel approach that applies Gene Ontology Term Analysis to the motif hits and selected those that were qualified through this procedure. The computational results were validated using Chromatin Immunoprecipitation assays to assess the in vivo binding of AtoC to the predicted sites. This process verified twenty-two additional AtoC binding sites, located not only within intergenic regions, but also within gene-encoding sequences. Conclusions This study, by tracing a number of putative AtoC binding sites, has indicated an AtoC-related cross-regulatory function. This highlights the significance of computational genome-wide approaches in elucidating complex patterns of bacterial cell regulation.
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Affiliation(s)
- Eleftherios Pilalis
- Institute of Biological Research and Biotechnology, National Hellenic Research Foundation, Athens, Greece
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Olkhova E, Raba M, Bracher S, Hilger D, Jung H. Homology model of the Na+/proline transporter PutP of Escherichia coli and its functional implications. J Mol Biol 2010; 406:59-74. [PMID: 21130773 DOI: 10.1016/j.jmb.2010.11.045] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2010] [Revised: 11/19/2010] [Accepted: 11/22/2010] [Indexed: 01/08/2023]
Abstract
Na(+)/solute symporters are essential membrane integrated proteins that couple the flow of Na(+) ions driven by electrochemical Na(+) gradients to the transport of solutes across biological membranes. Here, we used a combination of molecular modeling techniques and evolutionary conservation analysis to construct and validate a first model of the Na(+)/proline symporter PutP of Escherichia coli based on the crystal structure of the bacterial Na(+)/galactose symporter vSGLT. Ligand docking experiments were employed to gain information about residues involved in proline binding. The proposed model is consistent with the available experimental data and was further validated by amino acid substitutions and kinetic and protein chemical analyses. Combination of the results of molecular modeling and functional studies predicts the location and organization of the Na(+) and proline binding sites. Remarkably, as proposed computationally and discovered here experimentally, residues Y140, W244, and Y248 of transmembrane segments 4 and 7 are found to be particularly important for PutP function and suggested to participate in proline binding and/or gating.
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Affiliation(s)
- Elena Olkhova
- Department of Molecular Membrane Biology, Max Planck Institute of Biophysics, Max-von-Laue Str. 3, D-60438 Frankfurt am Main, Germany.
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Abreu C, Sanguinetti M, Amillis S, Ramon A. UreA, the major urea/H+ symporter in Aspergillus nidulans. Fungal Genet Biol 2010; 47:1023-33. [PMID: 20633690 DOI: 10.1016/j.fgb.2010.07.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 06/16/2010] [Accepted: 07/08/2010] [Indexed: 10/19/2022]
Abstract
We report here the characterization of UreA, a high-affinity urea/H+ symporter of Aspergillus nidulans. The deletion of the encoding gene abolishes urea transport at low substrate concentrations, suggesting that in these conditions UreA is the sole transport system specific for urea in A. nidulans. The ureA gene is not inducible by urea or its precursors, but responds to nitrogen metabolite repression, necessitating for its expression the AreA GATA factor. In contrast to what was observed for other transporters in A. nidulans, repression by ammonium is also operative during the isotropic growth phase. The activity of UreA is down-regulated post-translationally by ammonium-promoted endocytosis. A number of homologues of UreA have been identified in A. nidulans and other Aspergilli, which cluster in four groups, two of which contain the urea transporters characterized so far in fungi and plants. This phylogeny may have arisen by gene duplication events, giving place to putative transport proteins that could have acquired novel, still unidentified functions.
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Affiliation(s)
- Cecilia Abreu
- Sección Bioquímica, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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Yadav V, Kumar M, Deep DK, Kumar H, Sharma R, Tripathi T, Tuteja N, Saxena AK, Johri AK. WITHDRAWN: A phosphate transporter from the root endophytic fungus Piriformospora indica plays a role in phosphate transport to the host plant. J Biol Chem 2010; 285:26532-44. [PMID: 20479005 PMCID: PMC2924090 DOI: 10.1074/jbc.m110.111021] [Citation(s) in RCA: 233] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2010] [Revised: 05/12/2010] [Indexed: 11/06/2022] Open
Abstract
Because pure cultures and a stable transformation system are not available for arbuscular mycorrhizal fungi, the role of their phosphate transporters for the symbiotic interaction with the plant up till now could not be studied. Here we report the cloning and the functional analysis of a gene encoding a phosphate transporter (PiPT) from the root endophytic fungus Piriformospora indica, which can be grown axenically. The PiPT polypeptide belongs to the major facilitator superfamily. Homology modeling reveals that PiPT exhibits twelve transmembrane helices divided into two halves connected by a large hydrophilic loop in the middle. The function of the protein encoded by PiPT was confirmed by complementation of a yeast phosphate transporter mutant. The kinetic analysis of PiPT (K(m) 25 mum) reveals that it belongs to the high affinity phosphate transporter family (Pht1). Expression of PiPT was localized to the external hyphae of P. indica colonized with maize plant root, which suggests that external hyphae are the initial site of phosphate uptake from the soil. To understand the physiological role of PiPT, knockdown transformants of the gene were prepared using electroporation and RNA interference. Knockdown transformants transported a significantly lower amount of phosphate to the host plant than wild-type P. indica. Higher amounts of phosphate were found in plants colonized with wild-type P. indica than that of non-colonized and plants colonized with knockdown PiPT P. indica. These observations suggest that PiPT is actively involved in the phosphate transportation and, in turn, P. indica helps improve the nutritional status of the host plant.
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Affiliation(s)
- Vikas Yadav
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Manoj Kumar
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Deepak Kumar Deep
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Hemant Kumar
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Ruby Sharma
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Takshashila Tripathi
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Narendra Tuteja
- the International Center for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi 110067, India
| | - Ajay Kumar Saxena
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
| | - Atul Kumar Johri
- From the School of Life Sciences, Jawaharlal Nehru University, New Meharuli Road, New Delhi 110067 and
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Bizhanova A, Kopp P. Minireview: The sodium-iodide symporter NIS and pendrin in iodide homeostasis of the thyroid. Endocrinology 2009; 150:1084-90. [PMID: 19196800 PMCID: PMC2654752 DOI: 10.1210/en.2008-1437] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Thyroid hormones are essential for normal development and metabolism. Thyroid hormone biosynthesis requires iodide uptake into the thyrocytes and efflux into the follicular lumen, where it is organified on selected tyrosyls of thyroglobulin. Uptake of iodide into the thyrocytes is mediated by an intrinsic membrane glycoprotein, the sodium-iodide symporter (NIS), which actively cotransports two sodium cations per each iodide anion. NIS-mediated transport of iodide is driven by the electrochemical sodium gradient generated by the Na(+)/K(+)-ATPase. NIS is expressed in the thyroid, the salivary glands, gastric mucosa, and the lactating mammary gland. TSH and iodide regulate iodide accumulation by modulating NIS activity via transcriptional and posttranscriptional mechanisms. Biallelic mutations in the NIS gene lead to a congenital iodide transport defect, an autosomal recessive condition characterized by hypothyroidism, goiter, low thyroid iodide uptake, and a low saliva/plasma iodide ratio. Pendrin is an anion transporter that is predominantly expressed in the inner ear, the thyroid, and the kidney. Biallelic mutations in the SLC26A4 gene lead to Pendred syndrome, an autosomal recessive disorder characterized by sensorineural deafness, goiter, and impaired iodide organification. In thyroid follicular cells, pendrin is expressed at the apical membrane. Functional in vitro data and the impaired iodide organification observed in patients with Pendred syndrome support a role of pendrin as an apical iodide transporter.
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Affiliation(s)
- Aigerim Bizhanova
- Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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Rückert C, Milse J, Albersmeier A, Koch DJ, Pühler A, Kalinowski J. The dual transcriptional regulator CysR in Corynebacterium glutamicum ATCC 13032 controls a subset of genes of the McbR regulon in response to the availability of sulphide acceptor molecules. BMC Genomics 2008; 9:483. [PMID: 18854009 PMCID: PMC2580772 DOI: 10.1186/1471-2164-9-483] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2008] [Accepted: 10/14/2008] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Regulation of sulphur metabolism in Corynebacterium glutamicum ATCC 13032 has been studied intensively in the last few years, due to its industrial as well as scientific importance. Previously, the gene cg0156 was shown to belong to the regulon of McbR, a global transcriptional repressor of sulphur metabolism in C. glutamicum. This gene encodes a putative ROK-type regulator, a paralogue of the activator of sulphonate utilisation, SsuR. Therefore, it is an interesting candidate for study to further the understanding of the regulation of sulphur metabolism in C. glutamicum. RESULTS Deletion of cg0156, now designated cysR, results in the inability of the mutant to utilise sulphate and aliphatic sulphonates. DNA microarray hybridisations revealed 49 genes with significantly increased and 48 with decreased transcript levels in presence of the native CysR compared to a cysR deletion mutant. Among the genes positively controlled by CysR were the gene cluster involved in sulphate reduction, fpr2 cysIXHDNYZ, and ssuR. Gel retardation experiments demonstrated that binding of CysR to DNA depends in vitro on the presence of either O-acetyl-L-serine or O-acetyl-L-homoserine. Mapping of the transcription start points of five transcription units helped to identify a 10 bp inverted repeat as the possible CysR binding site. Subsequent in vivo tests proved this motif to be necessary for CysR-dependent transcriptional regulation. CONCLUSION CysR acts as the functional analogue of the unrelated LysR-type regulator CysB from Escherichia coli, controlling sulphide production in response to acceptor availability. In both bacteria, gene duplication events seem to have taken place which resulted in the evolution of dedicated regulators for the control of sulphonate utilisation. The striking convergent evolution of network topology indicates the strong selective pressure to control the metabolism of the essential but often toxic sulphur-containing (bio-)molecules.
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Affiliation(s)
- Christian Rückert
- Institut für Systembiologie & Genomforschung, Universität Bielefeld, Universitätsstr. 25, D-33615 Bielefeld, Germany.
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Carvalho DP, Ferreira ACF. The importance of sodium/iodide symporter (NIS) for thyroid cancer management. ACTA ACUST UNITED AC 2008; 51:672-82. [PMID: 17891230 DOI: 10.1590/s0004-27302007000500004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Accepted: 02/17/2007] [Indexed: 01/02/2023]
Abstract
The thyroid gland has the ability to uptake and concentrate iodide, which is a fundamental step in thyroid hormone biosynthesis. Radioiodine has been used as a diagnostic and therapeutic tool for several years. However, the studies related to the mechanisms of iodide transport were only possible after the cloning of the gene that encodes the sodium/iodide symporter (NIS). The studies about the regulation of NIS expression and the possibility of gene therapy with the aim of transferring NIS gene to cells that normally do not express the symporter have also become possible. In the majority of hypofunctioning thyroid nodules, both benign and malignant, NIS gene expression is maintained, but NIS protein is retained in the intracellular compartment. The expression of NIS in non-thyroid tumoral cells in vivo has been possible through the transfer of NIS gene under the control of tissue-specific promoters. Apart from its therapeutic use, NIS has also been used for the localization of metastases by scintigraphy or PET-scan with 124I. In conclusion, NIS gene cloning led to an important development in the field of thyroid pathophysiology, and has also been fundamental to extend the use of radioiodine for the management of non-thyroid tumors.
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Affiliation(s)
- Denise P Carvalho
- Laboratório de Fisiologia Endócrina, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, RJ, Brazil.
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Raba M, Baumgartner T, Hilger D, Klempahn K, Härtel T, Jung K, Jung H. Function of transmembrane domain IX in the Na+/proline transporter PutP. J Mol Biol 2008; 382:884-93. [PMID: 18692508 DOI: 10.1016/j.jmb.2008.07.070] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 07/23/2008] [Accepted: 07/24/2008] [Indexed: 10/21/2022]
Abstract
Selected residues of transmembrane domain (TM) IX were previously shown to play key roles in ligand binding and transport in members of the Na(+)/solute symporter family. Using the Na(+)/proline transporter PutP as a model, a complete Cys scanning mutagenesis of TM IX (positions 324 to 351) was performed here to further investigate the functional significance of the domain. G328, S332, Q345, and L346 were newly identified as important for Na(+)-coupled proline uptake. Placement of Cys at one of these positions altered K(m(pro)) (S332C and L346C, 3- and 21-fold decreased, respectively; Q345C, 38-fold increased), K(0.5(Na+)) (S332C, 13-fold decreased; Q345C, 19-fold increased), and/or V(max) [G328C, S332C, Q345C, and L346C, 3-, 22-, 2-, and 8-fold decreased compared to PutP(wild type), respectively]. Membrane-permeant N-ethylmaleimide inhibited proline uptake into cells containing PutP with Cys at distinct positions in the middle (T341C) and cytoplasmic half of TM IX (C344, L347C, V348C, and S351C) and had little or no effect on all other single Cys PutP variants. The inhibition pattern was in agreement with the pattern of labeling with fluorescein-5-maleimide. In addition, Cys placed into the cytoplasmic half of TM IX (C344, L347C, V348C, and S351C) was protected from fluorescein-5-maleimide labeling by proline while Na(+) alone had no effect. Membrane-impermeant methanethiosulfonate ethyltrimethylammonium modified Cys in the middle (A337C and T341C) and periplasmic half (L331C) but not in the cytoplasmic half of TM IX in intact cells. Furthermore, Cys at the latter positions was partially protected by Na(+) but not by proline. Based on these results, a model is discussed according to which residues of TM IX participate in the formation of ligand-sensitive, hydrophilic cavities in the protein that may reconstitute part of the Na(+) and/or proline translocation pathway of PutP.
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Affiliation(s)
- Michael Raba
- LMU Munich, Department Biology I, Microbiology, Grosshaderner Strasse 2-4, D-82152 Planegg-Martinsried, Germany
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Chuang YC, Wang KC, Chen YT, Yang CH, Men SC, Fan CC, Chang LH, Yeh KS. Identification of the genetic determinants of Salmonella enterica serotype Typhimurium that may regulate the expression of the type 1 fimbriae in response to solid agar and static broth culture conditions. BMC Microbiol 2008; 8:126. [PMID: 18652702 PMCID: PMC2527010 DOI: 10.1186/1471-2180-8-126] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2008] [Accepted: 07/25/2008] [Indexed: 12/29/2022] Open
Abstract
Background Type 1 fimbriae are the most commonly found fimbrial appendages on the outer membrane of Salmonella enterica serotype Typhimurium. Previous investigations indicate that static broth culture favours S. Typhimurium to produce type 1 fimbriae, while non-fimbriate bacteria are obtained by growth on solid agar media. The phenotypic expression of type 1 fimbriae in S. Typhimurium is the result of the interaction and cooperation of several genes in the fim gene cluster. Other gene products that may also participate in the regulation of type 1 fimbrial expression remain uncharacterized. Results In the present study, transposon insertion mutagenesis was performed on S. Typhimurium to generate a library to screen for those mutants that would exhibit different type 1 fimbrial phenotypes than the parental strain. Eight-two mutants were obtained from 7,239 clones screened using the yeast agglutination test. Forty-four mutants produced type 1 fimbriae on both solid agar and static broth media, while none of the other 38 mutants formed type 1 fimbriae in either culture condition. The flanking sequences of the transposons from 54 mutants were cloned and sequenced. These mutants can be classified according to the functions or putative functions of the open reading frames disrupted by the transposon. Our current results indicate that the genetic determinants such as those involved in the fimbrial biogenesis and regulation, global regulators, transporter proteins, prophage-derived proteins, and enzymes of different functions, to name a few, may play a role in the regulation of type 1 fimbrial expression in response to solid agar and static broth culture conditions. A complementation test revealed that transforming a recombinant plasmid possessing the coding sequence of a NAD(P)H-flavin reductase gene ubiB restored an ubiB mutant to exhibit the type 1 fimbrial phenotype as its parental strain. Conclusion Genetic determinants other than the fim genes may involve in the regulation of type 1 fimbrial expression in S. Typhimurium. How each gene product may influence type 1 fimbrial expression is an interesting research topic which warrants further investigation.
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Affiliation(s)
- Yin-Ching Chuang
- Department of Medical Research, Chi Mei Medical Center, 901 Chung Hwa Road, Yong Kang City, Tainan 710, Taiwan.
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Kim SH, Kim KI, Ju HW, Lee HJ, Hong SW. Overexpression of Gene Encoding Tonoplast Intrinsic Aquaporin Promotes Urea Transport in Arabidopsis. ACTA ACUST UNITED AC 2008. [DOI: 10.3839/jabc.2008.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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47
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Singh B, Röhm KH. Characterization of a Pseudomonas putida ABC transporter (AatJMQP) required for acidic amino acid uptake: biochemical properties and regulation by the Aau two-component system. Microbiology (Reading) 2008; 154:797-809. [DOI: 10.1099/mic.0.2007/013185-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Birendra Singh
- Philipps University, Institute of Physiological Chemistry, D-35043 Marburg, Germany
| | - Klaus-Heinrich Röhm
- Philipps University, Institute of Physiological Chemistry, D-35043 Marburg, Germany
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Hilger D, Böhm M, Hackmann A, Jung H. Role of Ser-340 and Thr-341 in transmembrane domain IX of the Na+/proline transporter PutP of Escherichia coli in ligand binding and transport. J Biol Chem 2007; 283:4921-9. [PMID: 18156179 DOI: 10.1074/jbc.m706741200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The Na+/solute symporter family comprises more than 400 members of pro- and eukaryotic origin. Using the Na+/proline transporter PutP of Escherichia coli as a model, the role of two conserved residues, Ser-340 and Thr-341, is investigated to obtain insights into the mechanism of transport catalyzed by members of this family. Substitution of these amino acids alters the transport kinetics of cells and proteoliposomes containing the PutP variants significantly. In particular, the apparent affinities for Na+ and Li+ are reduced by 2 orders of magnitude or more. Also proline binding is affected, albeit to a lesser extent than ion binding. Thereby, the presence of a hydroxyl group at position 341 is essential for high affinity ligand binding. Furthermore, Cys placed at position 340 or 341 reacts with sulfhydryl reagents of different polarity, indicating accessibility from the water phase. In addition, Cys cross-linking suggests proximity of the residues to other amino acids previously shown to be crucial for ligand binding. For these reasons it is suggested that Ser-340 and Thr-341 are located in a ligand translocation pathway. Furthermore, it is proposed that the side chain of Thr-341 directly participates in Na+ binding.
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Affiliation(s)
- Daniel Hilger
- LMU Munich, Department Biology I, Microbiology and Munich Center for integrated Protein Science (CiPS), D-80638 Munich, Germany
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49
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Manolescu AR, Witkowska K, Kinnaird A, Cessford T, Cheeseman C. Facilitated hexose transporters: new perspectives on form and function. Physiology (Bethesda) 2007; 22:234-40. [PMID: 17699876 DOI: 10.1152/physiol.00011.2007] [Citation(s) in RCA: 150] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The recent sequencing of the human genome has resulted in the addition of nine new hGLUT isoforms to the SLC2A family, many of which have widely varying substrate specificity, kinetic behavior, and tissue distribution. This review examines some new hypotheses related to the structure and function of these proteins.
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Affiliation(s)
- Andrei R Manolescu
- Membrane Protein Research Group, Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
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50
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Kojima S, Bohner A, Gassert B, Yuan L, von Wirén N. AtDUR3 represents the major transporter for high-affinity urea transport across the plasma membrane of nitrogen-deficient Arabidopsis roots. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2007; 52:30-40. [PMID: 17672841 DOI: 10.1111/j.1365-313x.2007.03223.x] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Despite the fact that urea is a ubiquitous nitrogen source in soils and the most widespread form of nitrogen fertilizer used in agricultural plant production, membrane transporters that might contribute to the uptake of urea in plant roots have so far been characterized only in heterologous systems. Two T-DNA insertion lines, atdur3-1 and atdur3-3, that showed impaired growth on urea as a sole nitrogen source were used to investigate a role of the H+/urea co-transporter AtDUR3 in nitrogen nutrition in Arabidopsis. In transgenic lines expressing AtDUR3-promoter:GFP constructs, promoter activity was upregulated under nitrogen deficiency and localized to the rhizodermis, including root hairs, as well as to the cortex in more basal root zones. Protein gel blot analysis of two-phase partitioned root membrane fractions and whole-mount immunolocalization in root hairs revealed the plasma membrane to be enriched in AtDUR3 protein. Expression of the AtDUR3 gene in nitrogen-deficient roots was repressed by ammonium and nitrate but induced after supply of urea. Higher accumulation of urea in roots of wild-type plants relative to atdur3-1 and atdur3-3 confirmed that urea was the substrate transported by AtDUR3. Influx of 15N-labeled urea in atdur3-1 and atdur3-3 showed a linear concentration dependency up to 200 microM external urea, whereas influx in wild-type roots followed saturation kinetics with an apparent Km of 4 microM. The results indicate that AtDUR3 is the major transporter for high-affinity urea uptake in Arabidopsis roots and suggest that the high substrate affinity of AtDUR3 reflects an adaptation to the low urea levels usually found in unfertilized soils.
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Affiliation(s)
- Soichi Kojima
- Molecular Plant Nutrition, Institute for Plant Nutrition, University of Hohenheim, D-70593 Stuttgart, Germany
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