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Pochini L. Involvement of mammalian SoLute Carriers (SLC) in the traffic of polyamines. Front Mol Biosci 2024; 11:1452184. [PMID: 39130372 PMCID: PMC11310933 DOI: 10.3389/fmolb.2024.1452184] [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: 06/20/2024] [Accepted: 07/10/2024] [Indexed: 08/13/2024] Open
Abstract
Polyamines interact with different molecular targets to regulate a vast range of cellular processes. A network of enzymes and transport systems is crucial for the maintenance of polyamine homeostasis. Indeed, polyamines after synthesis must be distributed to the various tissues and some intracellular organelles. Differently from the well characterized enzymes devoted to polyamine synthesis, the transport systems are not unequivocally identified or characterized. Besides some ATPases which have been identified as polyamine transporters, much less is known about solute carriers (SLC) involved in the transport of these compounds. Only two SLCs have been unequivocally identified as polyamine transporters: SLC18B1 (VPAT) and SLC22A4 (OCTN1). Transport studies have been performed with cells transfected with the cDNAs encoding the two and other SLCs or, in the case of OCTN1, also by in vitro assay using proteoliposomes harboring the recombinant human protein. According to the role proposed for OCTN1, polyamines have been associated with prolonged and quality of life. This review provides an update on the most recent findings concerning the polyamine transporters or the prediction of the putative ones.
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Affiliation(s)
- Lorena Pochini
- Laboratory of Biochemistry, Molecular Biotechnology and Molecular Biology, Department DiBEST (Biologia, Ecologia, Scienze Della Terra), University of Calabria, Rende, Italy
- Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), National Research Council (CNR), Bari, Italy
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Pochini L, Barone F, Console L, Brunocilla C, Galluccio M, Scalise M, Indiveri C. OCTN1 (SLC22A4) displays two different transport pathways for organic cations or zwitterions. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184263. [PMID: 38092232 DOI: 10.1016/j.bbamem.2023.184263] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/15/2023] [Accepted: 12/08/2023] [Indexed: 12/19/2023]
Abstract
BACKGROUND OCTN1 belongs to the SLC22 family, which includes transporters for cationic, zwitterionic, and anionic substrates. OCTN1 function and role in cells are still poorly understood. Not only cations, such as TEA, but also zwitterions, such as carnitine and ergothioneine, figure among transported molecules. METHODS In this work, we carried out transport assays measuring [14C]-TEA and [3H]-Carnitine in proteoliposomes reconstituted with the recombinant human OCTN1 in the presence of Na+ or other cations. The homology model of OCTN1 was built using the structure of OCT3 as a template for docking analysis. RESULTS TEA and carnitine did not inhibit each other. Moreover, carnitine uptake was not affected by the presence of Na+ and TEBA, whereas TEA was strongly inhibited by both compounds. Computational data revealed that TEA, Na+, and carnitine can interact with E381 in the OCTN1 substrate site. Differently from TEA, in the presence of Na+, carnitine is still able to interact with the binding site via R469. CONCLUSIONS The lack of mutual inhibition of the two prototype substrates, the different effect of Na+ and TEBA on their transport reaction, together with the computational analysis supports the existence of two transport pathways for cations and zwitterions. GENERAL SIGNIFICANCE The results shed new light on the transport mechanisms of OCTN1, helping to get further insights into the structure/function relationships. The described results correlate well with previous and very recent findings on the polyspecificity of the OCT group of transporters belonging to the same family.
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Affiliation(s)
- Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; National Research Council (CNR), Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), via Amendola 122/O, 70126 Bari, Italy
| | - Francesca Barone
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy
| | - Lara Console
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy
| | - Chiara Brunocilla
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy
| | - Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy.
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; National Research Council (CNR), Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), via Amendola 122/O, 70126 Bari, Italy.
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Galluccio M, Mazza T, Scalise M, Tripicchio M, Scarpelli M, Tolomeo M, Pochini L, Indiveri C. Over-Production of the Human SLC7A10 in E. coli and Functional Assay in Proteoliposomes. Int J Mol Sci 2023; 25:536. [PMID: 38203703 PMCID: PMC10779382 DOI: 10.3390/ijms25010536] [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] [Received: 11/30/2023] [Revised: 12/28/2023] [Accepted: 12/28/2023] [Indexed: 01/12/2024] Open
Abstract
The human SLC7A10 transporter, also known as ASC-1, catalyzes the transport of some neutral amino acids. It is expressed in astrocytes, neurons, and adipose tissues, playing roles in learning, memory processes, and lipid metabolism, thus being involved in neurological and metabolic pathologies. Structure/function studies on this transporter are still in their infancy. In this study, we present a methodology for producing the recombinant human transporter in E. coli. Its transport function was assayed in proteoliposomes following the uptake of radiolabeled L-serine. After the testing of several growth conditions, the hASC-1 transporter was successfully expressed in BL21(DE3) codon plus RIL in the presence of 0.5% glucose and induced with 0.05 mM IPTG. After solubilization with C12E8 and cholesteryl hemisuccinate and purification by Ni-chelating chromatography, hASC-1 was reconstituted in proteoliposomes. In this experimental system it was able to catalyze an Na+-independent homologous antiport of L-serine. A Km for L-serine transport of 0.24 mM was measured. The experimental model developed in this work represents a reproducible system for the transport assay of hASC-1 in the absence of interferences. This tool will be useful to unveil unknown transport properties of hASC-1 and for testing ligands with possible application in human pharmacology.
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Affiliation(s)
- Michele Galluccio
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
| | - Tiziano Mazza
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
| | - Mariafrancesca Scalise
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
| | - Martina Tripicchio
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
| | - Martina Scarpelli
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
| | - Maria Tolomeo
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
| | - Lorena Pochini
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
- National Research Council (CNR), Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), Via Amendola 122/O, 70126 Bari, Italy
| | - Cesare Indiveri
- Laboratory of Biochemistry, Molecular Biotechnology, and Molecular Biology, Department DiBEST (Biologia, Ecologia e Scienze della Terra), University of Calabria, Via Bucci 4C, 6C, 87036 Arcavacata di Rende, Italy; (T.M.); (M.S.); (M.T.); (M.S.); (M.T.); (L.P.)
- National Research Council (CNR), Institute of Biomembranes, Bioenergetics and Molecular Biotechnologies (IBIOM), Via Amendola 122/O, 70126 Bari, Italy
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Galluccio M, Scalise M, Pappacoda G, Scarpelli M, Bonanomi M, Gaglio D, Indiveri C. Production of recombinant human xCT (SLC7A11) and reconstitution in proteoliposomes for functional studies. Front Physiol 2022; 13:993626. [PMID: 36148304 PMCID: PMC9485625 DOI: 10.3389/fphys.2022.993626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 08/16/2022] [Indexed: 11/13/2022] Open
Abstract
The plasma membrane transporter xCT belongs to the SLC7 family and has the physiological role of mediating the exchange of glutamate and cystine across the cell plasma membrane, being crucial for redox control. The xCT protein forms a heterodimer with the ancillary protein CD98. Over the years, xCT became a hot pharmacological target due to the documented over-expression in virtually all human cancers, which rely on cystine availability for their progression. Notwithstanding, several unknown aspects of xCT biology still exist that require a suitable single protein experimental model, to be addressed. To this aim, the recombinant host Escherichia coli has been exploited to over-express the human isoform of xCT. In this widely used and low-cost system, the optimization for growth and protein production has been achieved by acting on the metabolic needs of the bacterial strains. Then, the His-tagged protein has been purified by Ni2+-chelating chromatography and reconstituted in proteoliposomes for transport activity assays. The expressed protein was in a folded/active state allowing functional and kinetic characterization. Interestingly, the features of the recombinant protein meet those of the native one extracted from intact cells, further confirming the suitability of E. coli as a host for the expression of human proteins. This study opens perspectives for elucidating other molecular aspects of xCT, as well as for studying the interaction with endogenous and exogenous compounds, relevant to human health.
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Affiliation(s)
- Michele Galluccio
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia Ecologia Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
| | - Mariafrancesca Scalise
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia Ecologia Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
| | - Gilda Pappacoda
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia Ecologia Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
| | - Martina Scarpelli
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia Ecologia Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
| | - Marcella Bonanomi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Milan, Italy
- ISBE.IT/Centre of Systems Biology, Milan, Italy
| | - Daniela Gaglio
- ISBE.IT/Centre of Systems Biology, Milan, Italy
- Institute of Molecular Bioimaging and Physiology (IBFM), National Research Council (CNR), Milan, Italy
| | - Cesare Indiveri
- Unit of Biochemistry and Molecular Biotechnology, Department DiBEST (Biologia Ecologia Scienze della Terra), University of Calabria, Arcavacata di Rende, Italy
- CNR Institute of Biomembranes, Bioenergetics, and Molecular Biotechnologies (IBIOM), Bari, Italy
- *Correspondence: Cesare Indiveri,
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Heterologous (Over) Expression of Human SoLute Carrier (SLC) in Yeast: A Well-Recognized Tool for Human Transporter Function/Structure Studies. LIFE (BASEL, SWITZERLAND) 2022; 12:life12081206. [PMID: 36013385 PMCID: PMC9410066 DOI: 10.3390/life12081206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 08/02/2022] [Accepted: 08/04/2022] [Indexed: 11/16/2022]
Abstract
For more than 20 years, yeast has been a widely used system for the expression of human membrane transporters. Among them, more than 400 are members of the largest transporter family, the SLC superfamily. SLCs play critical roles in maintaining cellular homeostasis by transporting nutrients, ions, and waste products. Based on their involvement in drug absorption and in several human diseases, they are considered emerging therapeutic targets. Despite their critical role in human health, a large part of SLCs' is 'orphans' for substrate specificity or function. Moreover, very few data are available concerning their 3D structure. On the basis of the human health benefits of filling these knowledge gaps, an understanding of protein expression in systems that allow functional production of these proteins is essential. Among the 500 known yeast species, S. cerevisiae and P. pastoris represent those most employed for this purpose. This review aims to provide a comprehensive state-of-the-art on the attempts of human SLC expression performed by exploiting yeast. The collected data will hopefully be useful for guiding new attempts in SLCs expression with the aim to reveal new fundamental data that could lead to potential effects on human health.
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