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Ben Mariem O, Palazzolo L, Torre B, Wei Y, Bianchi D, Guerrini U, Laurenzi T, Saporiti S, De Fabiani E, Pochini L, Indiveri C, Eberini I. Atomistic description of the OCTN1 recognition mechanism via in silico methods. PLoS One 2024; 19:e0304512. [PMID: 38829838 PMCID: PMC11146731 DOI: 10.1371/journal.pone.0304512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 05/14/2024] [Indexed: 06/05/2024] Open
Abstract
The Organic Cation Transporter Novel 1 (OCTN1), also known as SLC22A4, is widely expressed in various human tissues, and involved in numerous physiological and pathological processes remains. It facilitates the transport of organic cations, zwitterions, with selectivity for positively charged solutes. Ergothioneine, an antioxidant compound, and acetylcholine (Ach) are among its substrates. Given the lack of experimentally solved structures of this protein, this study aimed at generating a reliable 3D model of OCTN1 to shed light on its substrate-binding preferences and the role of sodium in substrate recognition and transport. A chimeric model was built by grafting the large extracellular loop 1 (EL1) from an AlphaFold-generated model onto a homology model. Molecular dynamics simulations revealed domain-specific mobility, with EL1 exhibiting the highest impact on overall stability. Molecular docking simulations identified cytarabine and verapamil as highest affinity ligands, consistent with their known inhibitory effects on OCTN1. Furthermore, MM/GBSA analysis allowed the categorization of substrates into weak, good, and strong binders, with molecular weight strongly correlating with binding affinity to the recognition site. Key recognition residues, including Tyr211, Glu381, and Arg469, were identified through interaction analysis. Ach demonstrated a low interaction energy, supporting the hypothesis of its one-directional transport towards to outside of the membrane. Regarding the role of sodium, our model suggested the involvement of Glu381 in sodium binding. Molecular dynamics simulations of systems at increasing levels of Na+ concentrations revealed increased sodium occupancy around Glu381, supporting experimental data associating Na+ concentration to molecule transport. In conclusion, this study provides valuable insights into the 3D structure of OCTN1, its substrate-binding preferences, and the role of sodium in the recognition. These findings contribute to the understanding of OCTN1 involvement in various physiological and pathological processes and may have implications for drug development and disease management.
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Affiliation(s)
- Omar Ben Mariem
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Luca Palazzolo
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Beatrice Torre
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Yao Wei
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Davide Bianchi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Uliano Guerrini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Tommaso Laurenzi
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Simona Saporiti
- Analytical Excellence and Program Management, Merck Serono S.p.A., Rome, Italy
| | - Emma De Fabiani
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
| | - Lorena Pochini
- Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Arcavacata CS, Italy
| | - Cesare Indiveri
- Dipartimento di Biologia, Ecologia e Scienze della Terra, Università della Calabria, Arcavacata CS, Italy
- CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), Bari, Italy
| | - Ivano Eberini
- Dipartimento di Scienze Farmacologiche e Biomolecolari, Università degli Studi di Milano, Milan, Italy
- DSRC, Università degli Studi di Milano, Milan, Italy
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2
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Galluccio M, Console L, Pochini L, Scalise M, Giangregorio N, Indiveri C. Strategies for Successful Over-Expression of Human Membrane Transport Systems Using Bacterial Hosts: Future Perspectives. Int J Mol Sci 2022; 23:ijms23073823. [PMID: 35409183 PMCID: PMC8998559 DOI: 10.3390/ijms23073823] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 03/28/2022] [Accepted: 03/28/2022] [Indexed: 02/06/2023] Open
Abstract
Ten percent of human genes encode for membrane transport systems, which are key components in maintaining cell homeostasis. They are involved in the transport of nutrients, catabolites, vitamins, and ions, allowing the absorption and distribution of these compounds to the various body regions. In addition, roughly 60% of FDA-approved drugs interact with membrane proteins, among which are transporters, often responsible for pharmacokinetics and side effects. Defects of membrane transport systems can cause diseases; however, knowledge of the structure/function relationships of transporters is still limited. Among the expression of hosts that produce human membrane transport systems, E. coli is one of the most favorable for its low cultivation costs, fast growth, handiness, and extensive knowledge of its genetics and molecular mechanisms. However, the expression in E. coli of human membrane proteins is often toxic due to the hydrophobicity of these proteins and the diversity in structure with respect to their bacterial counterparts. Moreover, differences in codon usage between humans and bacteria hamper translation. This review summarizes the many strategies exploited to achieve the expression of human transport systems in bacteria, providing a guide to help people who want to deal with this topic.
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Affiliation(s)
- Michele Galluccio
- Unit of Biochemistry and Molecular Biotechnology, Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Via P. Bucci 4c, Arcavacata di Rende, 87036 Cosenza, Italy; (M.G.); (L.C.); (L.P.); (M.S.)
| | - Lara Console
- Unit of Biochemistry and Molecular Biotechnology, Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Via P. Bucci 4c, Arcavacata di Rende, 87036 Cosenza, Italy; (M.G.); (L.C.); (L.P.); (M.S.)
| | - Lorena Pochini
- Unit of Biochemistry and Molecular Biotechnology, Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Via P. Bucci 4c, Arcavacata di Rende, 87036 Cosenza, Italy; (M.G.); (L.C.); (L.P.); (M.S.)
| | - Mariafrancesca Scalise
- Unit of Biochemistry and Molecular Biotechnology, Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Via P. Bucci 4c, Arcavacata di Rende, 87036 Cosenza, Italy; (M.G.); (L.C.); (L.P.); (M.S.)
| | - Nicola Giangregorio
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnology (IBIOM), National Research Council (CNR), Via Amendola 165/A, 70126 Bari, Italy;
| | - Cesare Indiveri
- Unit of Biochemistry and Molecular Biotechnology, Department of Biology, Ecology and Earth Sciences (DiBEST), University of Calabria, Via P. Bucci 4c, Arcavacata di Rende, 87036 Cosenza, Italy; (M.G.); (L.C.); (L.P.); (M.S.)
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnology (IBIOM), National Research Council (CNR), Via Amendola 165/A, 70126 Bari, Italy;
- Correspondence:
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3
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Kuang X, Chi D, Li J, Guo C, Yang Y, Zhou S, Luo C, Liu H, He Z, Wang Y. Disulfide bond based cascade reduction-responsive Pt(IV) nanoassemblies for improved anti-tumor efficiency and biosafety. Colloids Surf B Biointerfaces 2021; 203:111766. [PMID: 33866279 DOI: 10.1016/j.colsurfb.2021.111766] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 03/18/2021] [Accepted: 04/10/2021] [Indexed: 12/11/2022]
Abstract
The platinum-based drugs prevail in the therapy of malignant tumors treatment. However, their clinical outcomes have been heavily restricted by severe systemic toxicities. To ensure biosafety and efficiency, herein, we constructed a disulfide bond inserted Pt(IV) self-assembled nanoplatform that is selectively activated by rich glutathione (GSH) in tumor site. Disulfide bond was introduced into the conjugates of oxaliplatin (IV) and oleic acid (OA) which conferred cascade reduction-responsiveness to nanoassemblies. Disulfide bond cleavage and reduction of Pt(IV) center occur sequentially as a cascade process. In comparison to oxaliplatin solution, Pt(IV) nanoparticles (NPs) achieved prolonged blood circulation and higher maximum tolerated doses. Furthermore, Oxa(IV)-SS-OA prodrug NPs exhibited potent anti-tumor efficiency against 4T1 cells and low toxicities in other normal tissues, which offers a promising nano-platform for potential clinical application.
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Affiliation(s)
- Xiao Kuang
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Dongxu Chi
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Jinbo Li
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Chunlin Guo
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Yinxian Yang
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Shuang Zhou
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Cong Luo
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Hongzhuo Liu
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Zhonggui He
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China
| | - Yongjun Wang
- Department of Pharmaceutics, Wuya College of Innovation, Shenyang Pharmaceutical University, Shenyang, 110016, China.
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4
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Galluccio M, Indiveri C. Heterologous Overexpression of Human FAD Synthase Isoforms 1 and 2. Methods Mol Biol 2021; 2280:55-67. [PMID: 33751429 DOI: 10.1007/978-1-0716-1286-6_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The study of human FAD synthase enzymes requires a recombinant strategy to produce large amount of purified proteins in a soluble form. E. coli was exploited to this aim. To achieve the production of FAD synthase in a large scale, E. coli strains, plasmids (promoter, tags), growth temperature, inducer concentration, medium composition, and osmotic pressure were optimized. To date there is no universal protocol for protein expression, but for each protein a specific combination of "expression parameters" can be selected in order to maximize the results. An experimental protocol for the expression of two isoforms of the human FAD synthase was set up. The final procedures are based on the use of E. coli Rosetta(DE3) strain. Two different plasmids were used to obtain optimal amount of the two protein isoforms. In both cases, following the addition of the IPTG inducer, the growth temperature was lowered to increase the solubility of the recombinant protein. The detailed procedures for FAD synthase isoform 1 and isoform 2 overproduction are described in this protocol.
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Affiliation(s)
- Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy.
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5
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Borodina I, Kenny LC, McCarthy CM, Paramasivan K, Pretorius E, Roberts TJ, van der Hoek SA, Kell DB. The biology of ergothioneine, an antioxidant nutraceutical. Nutr Res Rev 2020; 33:190-217. [PMID: 32051057 PMCID: PMC7653990 DOI: 10.1017/s0954422419000301] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 11/20/2019] [Accepted: 11/25/2019] [Indexed: 02/07/2023]
Abstract
Ergothioneine (ERG) is an unusual thio-histidine betaine amino acid that has potent antioxidant activities. It is synthesised by a variety of microbes, especially fungi (including in mushroom fruiting bodies) and actinobacteria, but is not synthesised by plants and animals who acquire it via the soil and their diet, respectively. Animals have evolved a highly selective transporter for it, known as solute carrier family 22, member 4 (SLC22A4) in humans, signifying its importance, and ERG may even have the status of a vitamin. ERG accumulates differentially in various tissues, according to their expression of SLC22A4, favouring those such as erythrocytes that may be subject to oxidative stress. Mushroom or ERG consumption seems to provide significant prevention against oxidative stress in a large variety of systems. ERG seems to have strong cytoprotective status, and its concentration is lowered in a number of chronic inflammatory diseases. It has been passed as safe by regulatory agencies, and may have value as a nutraceutical and antioxidant more generally.
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Affiliation(s)
- Irina Borodina
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
| | - Louise C. Kenny
- Department of Women’s and Children’s Health, Institute of Translational Medicine, University of Liverpool, Crown Street, LiverpoolL8 7SS, UK
| | - Cathal M. McCarthy
- Irish Centre for Fetal and Neonatal Translational Research (INFANT), Cork University Maternity Hospital, Cork, Republic of Ireland
- Department of Pharmacology and Therapeutics, Western Gateway Building, University College Cork, Cork, Republic of Ireland
| | - Kalaivani Paramasivan
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
| | - Etheresia Pretorius
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
| | - Timothy J. Roberts
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, LiverpoolL69 7ZB, UK
| | - Steven A. van der Hoek
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
| | - Douglas B. Kell
- The Novo Nordisk Foundation Center for Biosustainability, Building 220, Chemitorvet 200, Technical University of Denmark, 2800Kongens Lyngby, Denmark
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602, South Africa
- Department of Biochemistry, Institute of Integrative Biology, Faculty of Health and Life Sciences, University of Liverpool, Crown Street, LiverpoolL69 7ZB, UK
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6
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Low temperature bacterial expression of the neutral amino acid transporters SLC1A5 (ASCT2), and SLC6A19 (B0AT1). Mol Biol Rep 2020; 47:7283-7289. [PMID: 32772343 PMCID: PMC7415195 DOI: 10.1007/s11033-020-05717-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 08/02/2020] [Indexed: 11/28/2022]
Abstract
It is well established that Escherichia coli represents a powerful tool for the over-expression of human proteins for structure/function studies. In many cases, such as for membrane transporters, the bacterial toxicity or the aggregation of the target protein hamper the expression limiting the application of this tool. The aim of this study was finding the appropriate conditions for the expression of reluctant proteins that is the human neutral amino acid transporters ASCT2 and B0AT1, that have great relevance to human health in cancer therapy and in COVID-19 research, respectively. The cDNAs coding for the proteins of interest were cloned in the pCOLD I vector and different E. coli strains (BL21 codon plus RIL, and RosettaGami2) were cultured in absence or in presence of glucose (0.5–1%), at low temperature (15 °C), and low inducer concentrations (10–100 µM). Cell growth and protein production were monitored by optical density measurements and western blotting assay, respectively. Even though in different conditions, the expression of both amino acid transporters was obtained.Reducing the growth rate of specific E. coli strains by lowering the temperature and the IPTG concentration, together with the addition of glucose, two reluctant human neutral amino acid transporters have been expressed in E. coli. The results have a potentially great interest in drug discovery since ASCT2 is an acknowledged target of anticancer therapy, and B0AT1 together with ACE2 is part of a receptor for the SARS-Cov-2 RBD proteins.
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7
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Oppedisano F, Muscoli C, Musolino V, Carresi C, Macrì R, Giancotta C, Bosco F, Maiuolo J, Scarano F, Paone S, Nucera S, Zito MC, Scicchitano M, Ruga S, Ragusa M, Palma E, Tavernese A, Mollace R, Bombardelli E, Mollace V. The Protective Effect of Cynara Cardunculus Extract in Diet-Induced NAFLD: Involvement of OCTN1 and OCTN2 Transporter Subfamily. Nutrients 2020; 12:E1435. [PMID: 32429274 PMCID: PMC7284543 DOI: 10.3390/nu12051435] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 05/05/2020] [Accepted: 05/08/2020] [Indexed: 12/12/2022] Open
Abstract
Hyperlipidemia and insulin-resistance are often associated with Non-Alcoholic Fatty Liver Disease (NAFLD) thereby representing a true issue worldwide due to increased risk of developing cardiovascular and systemic disorders. Although clear evidence suggests that circulating fatty acids contribute to pathophysiological mechanisms underlying NAFLD and hyperlipidemia, further studies are required to better identify potential beneficial approaches for counteracting such a disease. Recently, several artichoke extracts have been used for both reducing hyperlipidemia, insulin-resistance and NAFLD, though the mechanism is unclear. Here we used a wild type of Cynara Cardunculus extract (CyC), rich in sesquiterpens and antioxidant active ingredients, in rats fed a High Fat Diet (HFD) compared to a Normal Fat Diet (NFD). In particular, in rats fed HFD for four consecutive weeks, we found a significant increase of serum cholesterol, triglyceride and serum glucose. This effect was accompanied by increased body weight and by histopathological features of liver steatosis. The alterations of metabolic parameters found in HFDs were antagonised dose-dependently by daily oral supplementation of rats with CyC 10 and 20 mg/kg over four weeks, an effect associated to significant improvement of liver steatosis. The effect of CyC (20 mg/kg) was also associated to enhanced expression of both OCTN1 and OCTN2 carnitine-linked transporters. Thus, present data suggest a contribution of carnitine system in the protective effect of CyC in diet-induced hyperlipidemia, insulin-resistance and NAFLD.
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Affiliation(s)
- Francesca Oppedisano
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Carolina Muscoli
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
- San Raffaele IRCCS, 00199 Rome, Italy
| | - Vincenzo Musolino
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Cristina Carresi
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Roberta Macrì
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Caterina Giancotta
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Francesca Bosco
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Jessica Maiuolo
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Federica Scarano
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Sara Paone
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Saverio Nucera
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Maria Caterina Zito
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Miriam Scicchitano
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Stefano Ruga
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Monica Ragusa
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Ernesto Palma
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Annamaria Tavernese
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Rocco Mollace
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Ezio Bombardelli
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
| | - Vincenzo Mollace
- Institute of Research for Food Safety & Health, Department of Health Sciences, University “Magna Graecia” of Catanzaro, 88100 Catanzaro, Italy; (F.O.); (C.M.); (V.M.); (C.C.); (R.M.); (C.G.); (F.B.); (J.M.); (F.S.); (S.P.); (S.N.); (M.C.Z.); (M.S.); (S.R.); (M.R.); (E.P.); (A.T.); (R.M.); (E.B.)
- San Raffaele IRCCS, 00199 Rome, Italy
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8
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Sengupta S, Jaiswal D, Sengupta A, Shah S, Gadagkar S, Wangikar PP. Metabolic engineering of a fast-growing cyanobacterium Synechococcus elongatus PCC 11801 for photoautotrophic production of succinic acid. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:89. [PMID: 32467730 PMCID: PMC7236211 DOI: 10.1186/s13068-020-01727-7] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 05/09/2020] [Indexed: 05/11/2023]
Abstract
BACKGROUND Cyanobacteria, a group of photosynthetic prokaryotes, are being increasingly explored for direct conversion of carbon dioxide to useful chemicals. However, efforts to engineer these photoautotrophs have resulted in low product titers. This may be ascribed to the bottlenecks in metabolic pathways, which need to be identified for rational engineering. We engineered the recently reported, fast-growing and robust cyanobacterium, Synechococcus elongatus PCC 11801 to produce succinate, an important platform chemical. Previously, engineering of the model cyanobacterium S. elongatus PCC 7942 has resulted in succinate titer of 0.43 g l-1 in 8 days. RESULTS Building on the previous report, expression of α-ketoglutarate decarboxylase, succinate semialdehyde dehydrogenase and phosphoenolpyruvate carboxylase yielded a succinate titer of 0.6 g l-1 in 5 days suggesting that PCC 11801 is better suited as host for production. Profiling of the engineered strains for 57 intermediate metabolites, a number of enzymes and qualitative analysis of key transcripts revealed potential flux control points. Based on this, we evaluated the effects of overexpression of sedoheptulose-1,7-bisphosphatase, citrate synthase and succinate transporters and knockout of succinate dehydrogenase and glycogen synthase A. The final construct with seven genes overexpressed and two genes knocked out resulted in photoautotrophic production of 0.93 g l-1 succinate in 5 days. CONCLUSION While the fast-growing strain PCC 11801 yielded a much higher titer than the model strain, the efficient photoautotrophy of this novel isolate needs to be harnessed further for the production of desired chemicals. Engineered strains of S. elongatus PCC 11801 showed dramatic alterations in the levels of several metabolites suggesting far reaching effects of pathway engineering. Attempts to overexpress enzymes deemed to be flux controlling led to the emergence of other potential rate-limiting steps. Thus, this process of debottlenecking of the pathway needs to be repeated several times to obtain a significantly superior succinate titer.
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Affiliation(s)
- Shinjinee Sengupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Damini Jaiswal
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Annesha Sengupta
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Shikha Shah
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Shruti Gadagkar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
| | - Pramod P. Wangikar
- Department of Chemical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- DBT-Pan IIT Center for Bioenergy, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
- Wadhwani Research Center for Bioengineering, Indian Institute of Technology Bombay, Powai, Mumbai, 400076 India
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9
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Li D, Qi C, Zhou J, Wen Z, Zhu X, Xia H, Song J. LPS-induced inflammation delays the transportation of ASP + due to down-regulation of OCTN1/2 in alveolar epithelial cells. J Drug Target 2019; 28:437-447. [PMID: 31591905 DOI: 10.1080/1061186x.2019.1678169] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Organic cation transporters (OCTNs) can significantly affect drug disposition in alveolar epithelial cells (A549), but this process is not well understood. We investigated the expression and function of OCTN1/2 in A549 cells under different inflammatory status to examine pulmonary drug distribution. This experiment used lipopolysaccharide (LPS)-treated A549 cells to mimic inflammation in alveolar epithelial cells, and the expression of OCTN1/2, interleukin-6 (IL6), IL18, IL1β and tumour necrosis factor-alpha (TNF-α) was investigated by western blot and quantitative real-time PCR (qRT-PCR). The fluorescent compound 4-(4-(dimethylamino)styryl)-N-methylpyridinium iodide (ASP+) was chosen as a probe to study the activity of OCTN1/2. OCTN1/2 down-regulation induced by LPS was more pronounced than that in normal control (NC) groups. Experiments further detected the release of inflammatory factors that revealed a negative correlation between OCTN1/2 expression and inflammation secretion in human alveolar epithelial cells exposed to different concentrations of LPS. The Michaelis constant (Km) and apparent permeability coefficient (Papp) of ASP+ were also decreased significantly. Our results thus show that LPS-induced inflammation could inhibit the expression and activity of OCTN1/2 in vitro and reduce the distribution of inhaled medicine in pulmonary diseases.
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Affiliation(s)
- Dalang Li
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Chuanzong Qi
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Jian Zhou
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Zeqiang Wen
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Xiangyu Zhu
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Hongguang Xia
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
| | - Jue Song
- Institute for Anhui Province Key Laboratory of Major Autoimmune Diseases, Anhui Institute of Innovative Drugs, School of Pharmacy, Anhui Medical University, Hefei, China.,Institute for the Key Laboratory of Anti-inflammatory and Immune Medicines, Ministry of Education, Hefei, China
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10
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Pochini L, Galluccio M, Scalise M, Console L, Indiveri C. OCTN: A Small Transporter Subfamily with Great Relevance to Human Pathophysiology, Drug Discovery, and Diagnostics. SLAS DISCOVERY 2018; 24:89-110. [PMID: 30523710 DOI: 10.1177/2472555218812821] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
OCTN is a small subfamily of membrane transport proteins that belongs to the larger SLC22 family. Two of the three members of the subfamily, namely, OCTN2 and OCTN1, are present in humans. OCTN2 plays a crucial role in the absorption of carnitine from diet and in its distribution to tissues, as demonstrated by the occurrence of severe pathologies caused by malfunctioning or altered expression of this transporter. These findings suggest avoiding a strict vegetarian diet during pregnancy and in childhood. Other roles of OCTN2 are related to the traffic of carnitine derivatives in many tissues. The role of OCTN1 is still unclear, despite the identification of some substrates such as ergothioneine, acetylcholine, and choline. Plausibly, the transporter acts on the control of inflammation and oxidative stress, even though knockout mice do not display phenotypes. A clear role of both transporters has been revealed in drug interaction and delivery. The polyspecificity of the OCTNs is at the base of the interactions with drugs. Interestingly, OCTN2 has been recently exploited in the prodrug approach and in diagnostics. A promising application derives from the localization of OCTN2 in exosomes that represent a noninvasive diagnostic tool.
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Affiliation(s)
- Lorena Pochini
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Michele Galluccio
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Lara Console
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Cesare Indiveri
- 1 Department DiBEST (Biologia, Ecologia, Scienze della Terra), Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy.,2 CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnology, Bari, Italy
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11
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Giangregorio N, Tonazzi A, Console L, Galluccio M, Porcelli V, Indiveri C. Structure/function relationships of the human mitochondrial ornithine/citrulline carrier by Cys site-directed mutagenesis. Relevance to mercury toxicity. Int J Biol Macromol 2018; 120:93-99. [DOI: 10.1016/j.ijbiomac.2018.08.069] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Revised: 08/12/2018] [Accepted: 08/14/2018] [Indexed: 12/19/2022]
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12
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Console L, Scalise M, Tonazzi A, Giangregorio N, Indiveri C. Characterization of Exosomal SLC22A5 (OCTN2) carnitine transporter. Sci Rep 2018; 8:3758. [PMID: 29491466 PMCID: PMC5830701 DOI: 10.1038/s41598-018-22170-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Accepted: 02/19/2018] [Indexed: 12/18/2022] Open
Abstract
Exosomes are extracellular vesicles involved in cell-to-cell communication. Previous large scale proteomics revealed that they contain SLC proteins. However, no data on the function of exosomal SLCs is available, so far. An SLC localized in exosomes was here characterized for the first time: the carnitine transporter OCTN2 (SLC22A5). The protein was detected by Western Blot analysis in HEK293 exosomes. To investigate the functional properties of the exosomal OCTN2, the proteins extracted from vesicles were reconstituted into proteolipsomes and the transport function was measured as uptake of 3H-carnitine. Transport was stimulated by sodium and was dependent on pH. 3H-carnitine uptake was inhibited by Acetyl-carnitine, but not by Asn, Gln and Arg thus excluding interference by ATB0,+, an amino acid transporter which also recognizes carnitine. Cardiolipin failed to stimulate transport, excluding the activity of the mitochondrial Carnitine/acylcarnitine transporter. Increased level of exosomal OCTN2 was induced by treatment of HEK293 with the pro-inflammatory cytokine INFγ. All data concurred to demonstrate that OCTN2 present in exosomes is fully functional and is in its native conformation. Functional OCTN2 was detected also in human urinary exosomes, thus suggesting the OCTN2 exosomal protein as a candidate biomarker for inflammation related pathologies.
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Affiliation(s)
- Lara Console
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via Bucci 4C, 87036, Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via Bucci 4C, 87036, Arcavacata di Rende, Italy
| | - Annamaria Tonazzi
- CNR Institute of Biomembranes and Bioenergetics, via Amendola 165/A, 70126, Bari, Italy
| | - Nicola Giangregorio
- CNR Institute of Biomembranes and Bioenergetics, via Amendola 165/A, 70126, Bari, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via Bucci 4C, 87036, Arcavacata di Rende, Italy. .,CNR Institute of Biomembranes and Bioenergetics, via Amendola 165/A, 70126, Bari, Italy.
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13
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Regina TMR, Galluccio M, Scalise M, Pochini L, Indiveri C. Bacterial production and reconstitution in proteoliposomes of Solanum lycopersicum CAT2: a transporter of basic amino acids and organic cations. PLANT MOLECULAR BIOLOGY 2017; 94:657-667. [PMID: 28695314 DOI: 10.1007/s11103-017-0632-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
The vacuolar SlCAT2 was cloned, over-produced in E. coli and reconstituted in proteoliposomes. Arg, Ornithine and Lys were identified as substrates. Unexpectedly, also the organic cations Tetraethylammonium and Acetylcholine were transported indicating involvement of SlCAT2 in signaling. In land plants several transporters are involved in ion and metabolite flux across membranes of cells or intracellular organelles. The vacuolar amino acid transporter CAT2 from Solanum lycopersicum was investigated in this work. SlCAT2 was cloned from tomato flower cDNA, over-produced in Escherichia coli and purified by Nichel-chelating chromatography. For functional studies, the transporter was reconstituted in proteoliposomes. Competence of SlCAT2 for Arg transport was demonstrated measuring uptake of [3H]Arg in proteoliposomes which was trans-stimulated by internal Arg or ornithine. Uptake of [3H]Ornithine and [3H]Lys was also detected at lower efficiency with respect to [3H]Arg. Transport was activated by the presence of intraliposomal ATP suggesting regulation by the nucleotide. The prototype for organic cations tetraethylammonium (TEA) was also transported by SlCAT2. However, scarce reciprocal inhibition between TEA and Arg was found, while the biguanide metformin was able to strongly inhibit uptake of both substrates. These findings suggest that amino acids and organic cations may interact with the transporter through different functional groups some of which are common for the two types of substrates. Interestingly, reconstituted SlCAT2 showed competence for acetylcholine transport, which was also inhibited by metformin. Kinetics of Arg and Ach transport were performed from which Km values of 0.29 and 0.79 mM were derived, respectively.
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Affiliation(s)
- Teresa Maria Rosaria Regina
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Cosenza, Italy
| | - Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Cosenza, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Cosenza, Italy
| | - Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Cosenza, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036, Arcavacata di Rende, Cosenza, Italy.
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14
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Console L, Scalise M, Tarmakova Z, Coe IR, Indiveri C. N-linked glycosylation of human SLC1A5 (ASCT2) transporter is critical for trafficking to membrane. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1636-45. [PMID: 25862406 DOI: 10.1016/j.bbamcr.2015.03.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Revised: 03/26/2015] [Accepted: 03/31/2015] [Indexed: 12/11/2022]
Abstract
The human amino acid transporter SLC1A5 (ASCT2) contains two N-glycosylation sites (N163 and N212) located in the large extracellular loop. In the homology structural model of ASCT2 these Asn residues are extracellularly exposed. Mutants of the two Asn exhibited altered electrophoretic mobility. N163Q and N212Q displayed multiple bands with apparent molecular masses from 80kDa to 50kDa. N163/212Q displayed a single band of 50kDa corresponding to the unglycosylated protein. The presence in membrane of WT and mutants was evaluated by protein biotinylation assay followed by immunoblotting. The double mutation significantly impaired the presence of the protein in membrane, without impairment in protein synthesis. [(3)H]glutamine transport was measured in cells transiently transfected with the WT or mutants. N163/212Q exhibited a strongly reduced transport activity correlating with reduced surface expression. The same proteins extracted from cells and reconstituted in liposomes showed comparable transport activities demonstrating that the intrinsic transport function of the mutants was not affected. The rate of endocytosis of ASCT2 was assayed by a reversible biotinylation strategy. N212Q and N163/212Q showed strongly increased rates of endocytosis respect to WT. ASCT2 stability was determined using cycloheximide. N163Q or N163/212Q showed a slightly or significantly lower stability with respect to WT. To assess trafficking to the membrane, a brefeldin-based assay, which caused retention of proteins in ER, was performed. One hour after brefeldin removal WT protein was localized to the plasma membrane while the double mutant was localized in the cytosol. The results demonstrate that N-glycosylation is critical for trafficking.
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Affiliation(s)
- Lara Console
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy; Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Zlatina Tarmakova
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Imogen R Coe
- Department of Chemistry and Biology, Ryerson University, 350 Victoria St., Toronto M5B 2K3, Canada
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
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15
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Galluccio M, Pochini L, Peta V, Iannì M, Scalise M, Indiveri C. Functional and molecular effects of mercury compounds on the human OCTN1 cation transporter: C50 and C136 are the targets for potent inhibition. Toxicol Sci 2014; 144:105-13. [PMID: 25490951 DOI: 10.1093/toxsci/kfu259] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
The effect of mercury compounds has been tested on the organic cation transporter, hOCTN1. MeHg(+), Hg(2+), or Cd(2+) caused strong inhibition of transport. 1,4-Dithioerythritol (DTE), cysteine (Cys), and N-acetyl-l-cysteine reversed (NAC) the inhibition at different extents. 2-Aminoethyl methanethiosulfonate hydrobromide (MTSEA), a prototype SH reagent, exerted inhibition of transport similar to that observed for the mercurial agents. To investigate the mechanism of action of mercurials, mutants of hOCTN1 in which each of the Cys residues was substituted by Ala have been constructed, over-expressed in Escherichia coli, and purified. Tetraethylammonium chloride (TEA) uptake mediated by each mutant in proteoliposomes was comparable to that of wild type (WT). IC50 values of the WT and mutants for the mercury compounds were derived from dose-response analyses. The mutants C50A and C136A showed significant increase of IC50 indicating that the 2 Cys residues were involved in the interaction with the mercury compounds and inhibition of the transporter. The double mutant C50A/C136A was constructed; the lack of inhibition confirmed that the 2 Cys residues are the targets of mercury compounds. MTSEA showed similar behavior with respect to the mercurial reagents with the difference that increased IC50 was observed also in the C81A mutant. Similar results were obtained when transport was measured as acetylcholine uptake. Ethyl mercury (Thimerosal) inhibited hOCTN1 as well. C50A, C50A/C136A and, at very lower extent, C136A showed increased IC50 indicating that C50 was the major target of this mercury compound. The homology model of hOCTN1 was built using as template PiPT and validated by the experimental data on mutant proteins.
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Affiliation(s)
- Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, Via Bucci 4C, University of Calabria, 87036 Arcavacata di Rende, Italy
| | - Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, Via Bucci 4C, University of Calabria, 87036 Arcavacata di Rende, Italy
| | - Valentina Peta
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, Via Bucci 4C, University of Calabria, 87036 Arcavacata di Rende, Italy
| | - Maria Iannì
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, Via Bucci 4C, University of Calabria, 87036 Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, Via Bucci 4C, University of Calabria, 87036 Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, Via Bucci 4C, University of Calabria, 87036 Arcavacata di Rende, Italy
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16
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Pochini L, Scalise M, Galluccio M, Indiveri C. Membrane transporters for the special amino acid glutamine: structure/function relationships and relevance to human health. Front Chem 2014; 2:61. [PMID: 25157349 PMCID: PMC4127817 DOI: 10.3389/fchem.2014.00061] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Accepted: 07/16/2014] [Indexed: 12/26/2022] Open
Abstract
Glutamine together with glucose is essential for body's homeostasis. It is the most abundant amino acid and is involved in many biosynthetic, regulatory and energy production processes. Several membrane transporters which differ in transport modes, ensure glutamine homeostasis by coordinating its absorption, reabsorption and delivery to tissues. These transporters belong to different protein families, are redundant and ubiquitous. Their classification, originally based on functional properties, has recently been associated with the SLC nomenclature. Function of glutamine transporters is studied in cells over-expressing the transporters or, more recently in proteoliposomes harboring the proteins extracted from animal tissues or over-expressed in microorganisms. The role of the glutamine transporters is linked to their transport modes and coupling with Na+ and H+. Most transporters share specificity for other neutral or cationic amino acids. Na+-dependent co-transporters efficiently accumulate glutamine while antiporters regulate the pools of glutamine and other amino acids. The most acknowledged glutamine transporters belong to the SLC1, 6, 7, and 38 families. The members involved in the homeostasis are the co-transporters B0AT1 and the SNAT members 1, 2, 3, 5, and 7; the antiporters ASCT2, LAT1 and 2. The last two are associated to the ancillary CD98 protein. Some information on regulation of the glutamine transporters exist, which, however, need to be deepened. No information at all is available on structures, besides some homology models obtained using similar bacterial transporters as templates. Some models of rat and human glutamine transporters highlight very similar structures between the orthologs. Moreover the presence of glycosylation and/or phosphorylation sites located at the extracellular or intracellular faces has been predicted. ASCT2 and LAT1 are over-expressed in several cancers, thus representing potential targets for pharmacological intervention.
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Affiliation(s)
- Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
| | - Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria Arcavacata di Rende, Italy
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17
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Transport mechanism and regulatory properties of the human amino acid transporter ASCT2 (SLC1A5). Amino Acids 2014; 46:2463-75. [DOI: 10.1007/s00726-014-1808-x] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Accepted: 07/06/2014] [Indexed: 02/06/2023]
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18
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Galluccio M, Pingitore P, Scalise M, Indiveri C. Cloning, large scale over-expression in E. coli and purification of the components of the human LAT 1 (SLC7A5) amino acid transporter. Protein J 2014; 32:442-8. [PMID: 23912240 DOI: 10.1007/s10930-013-9503-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The high yield expression of the human LAT1 transporter has been obtained for the first time using E. coli. The hLAT1 cDNA was amplified from HEK293 cells and cloned in pH6EX3 vector. The construct pH6EX3-6His-hLAT1 was used to express the 6His-hLAT1 protein in the Rosetta(DE3)pLysS strain of E. coli. The highest level of expression was detected 8 h after induction by IPTG at 28 °C. The expressed protein was collected in the insoluble fraction of cell lysate. On SDS-PAGE the apparent molecular mass of the polypeptide was 40 kDa. After solubilization with sarkosyl and denaturation with urea the protein carrying a 6His N-terminal tag was purified by Ni(2+)-chelating affinity chromatography and identified by anti-His antibody. The yield of the over-expressed protein after purification was 3.5 mg/L (cell culture). The human CD98 cDNA amplified from Imagene plasmid was cloned in pGEX-4T1. The construct pGEX-4T1-hCD98 was used to express the GST-hCD98 protein in the Rosetta(DE3)pLysS strain of E. coli. The highest level of expression was detected in this case 4 h after induction by IPTG at 28 °C. The expressed protein was accumulated in the soluble fraction of cell lysate. The molecular mass was determined on the basis of marker proteins on SDS-PAGE; it was about 110 kDa. GST was cleaved from the protein construct by incubation with thrombin for 12 h and the hCD98 was separated by Sephadex G-200 chromatography (size exclusion). hCD98 showed a 62 kDa apparent molecular mass, as determined on the basis of molecular mass markers using SDS-PAGE. The yield of CD98 was 2 mg/L of cell culture.
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Affiliation(s)
- Michele Galluccio
- Unit of Biochemistry and Molecular Biotechnology, Department BEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Via P. Bucci 4c, 87036, Arcavacata di Rende, Italy
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Proteoliposomes as tool for assaying membrane transporter functions and interactions with xenobiotics. Pharmaceutics 2013; 5:472-97. [PMID: 24300519 PMCID: PMC3836619 DOI: 10.3390/pharmaceutics5030472] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2013] [Revised: 08/15/2013] [Accepted: 09/04/2013] [Indexed: 02/07/2023] Open
Abstract
Proteoliposomes represent a suitable and up to date tool for studying membrane transporters which physiologically mediate absorption, excretion, trafficking and reabsorption of nutrients and metabolites. Using recently developed reconstitution strategies, transporters can be inserted in artificial bilayers with the same orientation as in the cell membranes and in the absence of other interfering molecular systems. These methodologies are very suitable for studying kinetic parameters and molecular mechanisms. After the first applications on mitochondrial transporters, in the last decade, proteoliposomes obtained with optimized methodologies have been used for studying plasma membrane transporters and defining their functional and kinetic properties and structure/function relationships. A lot of information has been obtained which has clarified and completed the knowledge on several transporters among which the OCTN sub-family members, transporters for neutral amino acid, B0AT1 and ASCT2, and others. Transporters can mediate absorption of substrate-like derivatives or drugs, improving their bioavailability or can interact with these compounds or other xenobiotics, leading to side/toxic effects. Therefore, proteoliposomes have recently been used for studying the interaction of some plasma membrane and mitochondrial transporters with toxic compounds, such as mercurials, H2O2 and some drugs. Several mechanisms have been defined and in some cases the amino acid residues responsible for the interaction have been identified. The data obtained indicate proteoliposomes as a novel and potentially important tool in drug discovery.
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Pochini L, Scalise M, Galluccio M, Indiveri C. OCTN cation transporters in health and disease: role as drug targets and assay development. ACTA ACUST UNITED AC 2013; 18:851-67. [PMID: 23771822 DOI: 10.1177/1087057113493006] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The three members of the organic cation transporter novel subfamily are known to be involved in interactions with xenobiotic compounds. These proteins are characterized by 12 transmembrane segments connected by nine short loops and two large hydrophilic loops. It has been recently pointed out that acetylcholine is a physiological substrate of OCTN1. Its transport could be involved in nonneuronal cholinergic functions. OCTN2 maintains the carnitine homeostasis, resulting from intestinal absorption, distribution to tissues, and renal excretion/reabsorption. OCTN3, identified only in mouse, mediates also carnitine transport. OCTN1 and OCTN2 are associated with several pathologies, such as inflammatory bowel disease, primary carnitine deficiency, diabetes, neurological disorders, and cancer, thus representing useful pharmacological targets. The function and interaction with drugs of OCTNs have been studied in intact cell systems and in proteoliposomes. The latter experimental model enables reduced interference from other transporters or enzyme pathways. Using proteoliposomes, the molecular bases of toxicity of some drugs have recently been revealed. Therefore, proteoliposomes represent a promising experimental tool suitable for large-scale molecular screening of interactions of OCTNs with chemicals regarding human health.
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Affiliation(s)
- Lorena Pochini
- Laboratory of Biochemistry and Molecular Biotechnology, Department BEST (Biologia, Ecologia, Scienze della Terra), University of Calabria, Italy
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Pingitore P, Pochini L, Scalise M, Galluccio M, Hedfalk K, Indiveri C. Large scale production of the active human ASCT2 (SLC1A5) transporter in Pichia pastoris--functional and kinetic asymmetry revealed in proteoliposomes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1828:2238-46. [PMID: 23756778 DOI: 10.1016/j.bbamem.2013.05.034] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Revised: 05/28/2013] [Accepted: 05/31/2013] [Indexed: 12/11/2022]
Abstract
The human glutamine/neutral amino acid transporter ASCT2 (hASCT2) was over-expressed in Pichia pastoris and purified by Ni(2+)-chelating and gel filtration chromatography. The purified protein was reconstituted in liposomes by detergent removal with a batch-wise procedure. Time dependent [(3)H]glutamine/glutamine antiport was measured in proteoliposomes which was active only in the presence of external Na(+). Internal Na(+) slightly stimulated the antiport. Optimal activity was found at pH7.0. A substantial inhibition of the transport was observed by Cys, Thr, Ser, Ala, Asn and Met (≥70%) and by mercurials and methanethiosulfonates (≥80%). Heterologous antiport of [(3)H]glutamine with other neutral amino acids was also studied. The transporter showed asymmetric specificity for amino acids: Ala, Cys, Val, Met were only inwardly transported, while Gln, Ser, Asn, and Thr were transported bi-directionally. From kinetic analysis of [(3)H]glutamine/glutamine antiport Km values of 0.097 and 1.8mM were measured on the external and internal sides of proteoliposomes, respectively. The Km for Na(+) on the external side was 32mM. The homology structural model of the hASCT2 protein was built using the GltPh of Pyrococcus horikoshii as template. Cys395 was the only Cys residue externally exposed, thus being the potential target of SH reagents inhibition and, hence, potentially involved in the transport mechanism.
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Affiliation(s)
- Piero Pingitore
- Department BEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4c, 87036 Arcavacata di Rende, Italy.
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