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Yamaguchi Y, Ikeba K, Yoshida MA, Takagi W. Molecular basis of the unique osmoregulatory strategy in the inshore hagfish, Eptatretus burgeri. Am J Physiol Regul Integr Comp Physiol 2024; 327:R208-R233. [PMID: 38105762 DOI: 10.1152/ajpregu.00166.2023] [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: 07/03/2023] [Revised: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
Hagfishes are characterized by omo- and iono-conforming nature similar to marine invertebrates. Conventionally, hagfishes had been recognized as the most primitive living vertebrate that retains plesiomorphic features. However, some of the "ancestral" features of hagfishes, such as rudimentary eyes and the lack of vertebrae, have been proven to be deceptive. Similarly, by the principle of maximum parsimony, the unique body fluid regulatory strategy of hagfishes seems to be apomorphic, since the lamprey, another cyclostome, adopts osmo- and iono-regulatory mechanisms as in jawed vertebrates. Although hagfishes are unequivocally important in discussing the origin and evolution of the vertebrate osmoregulatory system, the molecular basis for the body fluid homeostasis in hagfishes has been poorly understood. In the present study, we explored this matter in the inshore hagfish, Eptatretus burgeri, by analyzing the transcriptomes obtained from the gill, kidney, and muscle of the animals acclimated to distinct environmental salinities. Together with the measurement of parameters in the muscular fluid compartment, our data indicate that the hagfish possesses an ability to conduct free amino acid (FAA)-based osmoregulation at a cellular level, which is in coordination with the renal and branchial FAA absorption. We also revealed that the hagfish does possess the orthologs of the known osmoregulatory genes and that the transepithelial movement of inorganic ions in the hagfish gill and kidney is more complex than previously thought. These observations pose a challenge to the conventional view that the physiological features of hagfishes have been inherited from the last common ancestor of the extant vertebrates.
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Affiliation(s)
- Yoko Yamaguchi
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Japan
| | - Kiriko Ikeba
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
| | - Masa-Aki Yoshida
- Institute of Agricultural and Life Sciences, Academic Assembly, Shimane University, Matsue, Japan
- Marine Biological Science Section, Education and Research Center for Biological Resources, Faculty of Life and Environmental Science, Shimane University, Okinoshima, Japan
| | - Wataru Takagi
- Laboratory of Physiology, Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Japan
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2
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Carecho R, Marques D, Carregosa D, Masuero D, Garcia-Aloy M, Tramer F, Passamonti S, Vrhovsek U, Ventura MR, Brito MA, Nunes Dos Santos C, Figueira I. Circulating low-molecular-weight (poly)phenol metabolites in the brain: unveiling in vitro and in vivo blood-brain barrier transport. Food Funct 2024; 15:7812-7827. [PMID: 38967492 DOI: 10.1039/d4fo01396d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/06/2024]
Abstract
Circulating metabolites resulting from colonic metabolism of dietary (poly)phenols are highly abundant in the bloodstream, though still marginally explored, particularly concerning their brain accessibility. Our goal is to disclose (poly)phenol metabolites' blood-brain barrier (BBB) transport, in vivo and in vitro, as well as their role at BBB level. For three selected metabolites, benzene-1,2-diol-3-sulfate/benzene-1,3-diol-2-sulfate (pyrogallol-sulfate - Pyr-sulf), benzene-1,3-diol-6-sulfate (phloroglucinol-sulfate - Phlo-sulf), and phenol-3-sulfate (resorcinol-sulfate - Res-sulf), BBB transport was assessed in human brain microvascular endothelial cells (HBMEC). Their potential in modulating in vitro BBB properties at circulating concentrations was also studied. Metabolites' fate towards the brain, liver, kidney, urine, and blood was disclosed in Wistar rats upon injection. Transport kinetics in HBMEC highlighted different BBB permeability rates, where Pyr-sulf emerged as the most in vitro BBB permeable metabolite. Pyr-sulf was also the most potent regarding BBB properties improvement, namely increased beta(β)-catenin membrane expression and reduction of zonula occludens-1 membrane gaps. Whereas no differences were observed for transferrin, increased expression of caveolin-1 upon Pyr-sulf and Res-sulf treatments was found. Pyr-sulf was also capable of modulating gene and protein expression of some solute carrier transporters. Notably, each of the injected metabolites exhibited a unique tissue distribution in vivo, with the remarkable ability to almost immediately reach the brain.
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Affiliation(s)
- Rafael Carecho
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal.
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Avenida da República, Oeiras, Portugal
| | - Daniela Marques
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal.
| | - Diogo Carregosa
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal.
| | - Domenico Masuero
- Metabolomics Unit, Research and Innovation Centre, Fondazione Edmund Mach (FEM), via E. Mach 1, San Michele all'Adige, Italy
| | - Mar Garcia-Aloy
- Metabolomics Unit, Research and Innovation Centre, Fondazione Edmund Mach (FEM), via E. Mach 1, San Michele all'Adige, Italy
| | - Federica Tramer
- Department of Life Sciences, University of Trieste, via L. Giorgieri 1, Trieste, Italy
| | - Sabina Passamonti
- Department of Life Sciences, University of Trieste, via L. Giorgieri 1, Trieste, Italy
| | - Urska Vrhovsek
- Metabolomics Unit, Research and Innovation Centre, Fondazione Edmund Mach (FEM), via E. Mach 1, San Michele all'Adige, Italy
| | - M Rita Ventura
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Avenida da República, Oeiras, Portugal
| | - Maria Alexandra Brito
- Research Institute for Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, Av. Prof. Gama Pinto, Lisboa, Portugal
| | - Cláudia Nunes Dos Santos
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal.
- Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Avenida da República, Oeiras, Portugal
- iBET, Instituto de Biologia Experimental e Tecnológica, Avenida da República, Apartado 12, Oeiras, Portugal
| | - Inês Figueira
- iNOVA4Health, NOVA Medical School, Faculdade de Ciências Médicas, Universidade NOVA de Lisboa, Campo dos Mártires da Pátria, Lisboa, Portugal.
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3
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Chen J, Ma B, Yang Y, Wang B, Hao J, Zhou X. Disulfidptosis decoded: a journey through cell death mysteries, regulatory networks, disease paradigms and future directions. Biomark Res 2024; 12:45. [PMID: 38685115 PMCID: PMC11059647 DOI: 10.1186/s40364-024-00593-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2024] [Accepted: 04/23/2024] [Indexed: 05/02/2024] Open
Abstract
Cell death is an important part of the life cycle, serving as a foundation for both the orderly development and the maintenance of physiological equilibrium within organisms. This process is fundamental, as it eliminates senescent, impaired, or aberrant cells while also promoting tissue regeneration and immunological responses. A novel paradigm of programmed cell death, known as disulfidptosis, has recently emerged in the scientific circle. Disulfidptosis is defined as the accumulation of cystine by cancer cells with high expression of the solute carrier family 7 member 11 (SLC7A11) during glucose starvation. This accumulation causes extensive disulfide linkages between F-actins, resulting in their contraction and subsequent detachment from the cellular membrane, triggering cellular death. The RAC1-WRC axis is involved in this phenomenon. Disulfidptosis sparked growing interest due to its potential applications in a variety of pathologies, particularly oncology, neurodegenerative disorders, and metabolic anomalies. Nonetheless, the complexities of its regulatory pathways remain elusive, and its precise molecular targets have yet to be definitively identified. This manuscript aims to meticulously dissect the historical evolution, molecular underpinnings, regulatory frameworks, and potential implications of disulfidptosis in various disease contexts, illuminating its promise as a groundbreaking therapeutic pathway and target.
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Affiliation(s)
- Jinyu Chen
- The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Boyuan Ma
- The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Yubiao Yang
- The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Bitao Wang
- The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China
| | - Jian Hao
- The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
| | - Xianhu Zhou
- The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, 510260, China.
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4
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Cheng X, Wang Y, Gong G, Shen P, Li Z, Bian J. Design strategies and recent development of bioactive modulators for glutamine transporters. Drug Discov Today 2024; 29:103880. [PMID: 38216118 DOI: 10.1016/j.drudis.2024.103880] [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] [Received: 09/12/2023] [Revised: 12/25/2023] [Accepted: 01/08/2024] [Indexed: 01/14/2024]
Abstract
Glutamine transporters are integral to the metabolism of glutamine in both healthy tissues and cancerous cells, playing a pivotal role in maintaining amino acid balance, synthesizing biomolecules, and regulating redox equilibrium. Their critical functions in cellular metabolism make them promising targets for oncological therapies. Recent years have witnessed substantial progress in the field of glutamine transporters, marked by breakthroughs in understanding of their protein structures and the discovery of novel inhibitors, prodrugs, and radiotracers. This review provides a comprehensive update on the latest advancements in modulators targeting the glutamine transporter, with special attention given to LAT1 and ASCT2. It also discusses innovative approaches in drug design aimed at these transporters.
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Affiliation(s)
- Xinying Cheng
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Yezhi Wang
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Guangyue Gong
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Pei Shen
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China
| | - Zhiyu Li
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
| | - Jinlei Bian
- School of Pharmacy, China Pharmaceutical University, Nanjing 210009, China.
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Jiang X, Peng Q, Peng M, Oyang L, Wang H, Liu Q, Xu X, Wu N, Tan S, Yang W, Han Y, Lin J, Xia L, Tang Y, Luo X, Dai J, Zhou Y, Liao Q. Cellular metabolism: A key player in cancer ferroptosis. Cancer Commun (Lond) 2024; 44:185-204. [PMID: 38217522 PMCID: PMC10876208 DOI: 10.1002/cac2.12519] [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: 08/17/2023] [Revised: 12/25/2023] [Accepted: 01/02/2024] [Indexed: 01/15/2024] Open
Abstract
Cellular metabolism is the fundamental process by which cells maintain growth and self-renewal. It produces energy, furnishes raw materials, and intermediates for biomolecule synthesis, and modulates enzyme activity to sustain normal cellular functions. Cellular metabolism is the foundation of cellular life processes and plays a regulatory role in various biological functions, including programmed cell death. Ferroptosis is a recently discovered form of iron-dependent programmed cell death. The inhibition of ferroptosis plays a crucial role in tumorigenesis and tumor progression. However, the role of cellular metabolism, particularly glucose and amino acid metabolism, in cancer ferroptosis is not well understood. Here, we reviewed glucose, lipid, amino acid, iron and selenium metabolism involvement in cancer cell ferroptosis to elucidate the impact of different metabolic pathways on this process. Additionally, we provided a detailed overview of agents used to induce cancer ferroptosis. We explained that the metabolism of tumor cells plays a crucial role in maintaining intracellular redox homeostasis and that disrupting the normal metabolic processes in these cells renders them more susceptible to iron-induced cell death, resulting in enhanced tumor cell killing. The combination of ferroptosis inducers and cellular metabolism inhibitors may be a novel approach to future cancer therapy and an important strategy to advance the development of treatments.
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Affiliation(s)
- Xianjie Jiang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Qiu Peng
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Mingjing Peng
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Linda Oyang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Honghan Wang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Department of Head and Neck Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
| | - Qiang Liu
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Xuemeng Xu
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Hengyang Medical School, University of South China, Hengyang, Hunan, P. R. China
| | - Nayiyuan Wu
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Shiming Tan
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
| | - Wenjuan Yang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
| | - Yaqian Han
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Jinguan Lin
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
| | - Longzheng Xia
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
| | - Yanyan Tang
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Xia Luo
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Jie Dai
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Department of Head and Neck Surgery, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
| | - Yujuan Zhou
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
| | - Qianjin Liao
- Hunan Key Laboratory of Cancer Metabolism, Hunan Cancer Hospital and the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, P. R. China
- Public Service Platform of Tumor Organoids Technology, Changsha, Hunan, P. R. China
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6
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Forteath C, Mordi I, Nisr R, Gutierrez-Lara EJ, Alqurashi N, Phair IR, Cameron AR, Beall C, Bahr I, Mohan M, Wong AKF, Dihoum A, Mohammad A, Palmer CNA, Lamont D, Sakamoto K, Viollet B, Foretz M, Lang CC, Rena G. Amino acid homeostasis is a target of metformin therapy. Mol Metab 2023; 74:101750. [PMID: 37302544 PMCID: PMC10328998 DOI: 10.1016/j.molmet.2023.101750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Revised: 04/04/2023] [Accepted: 06/05/2023] [Indexed: 06/13/2023] Open
Abstract
OBJECTIVE Unexplained changes in regulation of branched chain amino acids (BCAA) during diabetes therapy with metformin have been known for years. Here we have investigated mechanisms underlying this effect. METHODS We used cellular approaches, including single gene/protein measurements, as well as systems-level proteomics. Findings were then cross-validated with electronic health records and other data from human material. RESULTS In cell studies, we observed diminished uptake/incorporation of amino acids following metformin treatment of liver cells and cardiac myocytes. Supplementation of media with amino acids attenuated known effects of the drug, including on glucose production, providing a possible explanation for discrepancies between effective doses in vivo and in vitro observed in most studies. Data-Independent Acquisition proteomics identified that SNAT2, which mediates tertiary control of BCAA uptake, was the most strongly suppressed amino acid transporter in liver cells following metformin treatment. Other transporters were affected to a lesser extent. In humans, metformin attenuated increased risk of left ventricular hypertrophy due to the AA allele of KLF15, which is an inducer of BCAA catabolism. In plasma from a double-blind placebo-controlled trial in nondiabetic heart failure (trial registration: NCT00473876), metformin caused selective accumulation of plasma BCAA and glutamine, consistent with the effects in cells. CONCLUSIONS Metformin restricts tertiary control of BCAA cellular uptake. We conclude that modulation of amino acid homeostasis contributes to therapeutic actions of the drug.
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Affiliation(s)
- Calum Forteath
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Ify Mordi
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Raid Nisr
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Erika J Gutierrez-Lara
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Noor Alqurashi
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Iain R Phair
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Amy R Cameron
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK; Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Exeter, EX2 5DW, UK
| | - Craig Beall
- Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, RILD Building, Exeter, EX2 5DW, UK
| | - Ibrahim Bahr
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Mohapradeep Mohan
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Aaron K F Wong
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Adel Dihoum
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK; Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Anwar Mohammad
- Public Health and Epidemiology Department, Dasman Diabetes Institute, Kuwait City, Kuwait
| | - Colin N A Palmer
- Division of Population Health and Genomics, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK
| | - Douglas Lamont
- Centre for Advanced Scientific Technologies, School of Life Sciences, University of Dundee, Dundee, DD1 5EH, UK
| | - Kei Sakamoto
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Benoit Viollet
- Université Paris Cité, CNRS, Inserm, Institut Cochin, Paris, 75014, France
| | - Marc Foretz
- Université Paris Cité, CNRS, Inserm, Institut Cochin, Paris, 75014, France
| | - Chim C Lang
- Division of Molecular and Clinical Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK.
| | - Graham Rena
- Division of Cellular and Systems Medicine, Ninewells Hospital and Medical School, University of Dundee, Dundee, Scotland, DD1 9SY, UK.
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7
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Mohamed FE, Ghattas MA, Almansoori TM, Tabouni M, Baydoun I, Kizhakkedath P, John A, Alblooshi H, Shaukat Q, Al-Jasmi F. Novel compound heterozygous variants (c.971delA/c.542C > T) in SLC1A4 causes spastic tetraplegia, thin corpus callosum, and progressive microcephaly: a case report and mutational analysis. Front Pediatr 2023; 11:1183574. [PMID: 37502193 PMCID: PMC10369183 DOI: 10.3389/fped.2023.1183574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 06/26/2023] [Indexed: 07/29/2023] Open
Abstract
Spastic tetraplegia, thin corpus callosum, and progressive microcephaly (SPATCCM) are linked to SLC1A4 genetic variants since the first reported case in 2015. SLC1A4 encodes for the neutral amino acid transporter ASCT1 which is involved in the transportation of serine between astrocytes and neurons. Although most of the reported cases are of Ashkenazi Jewish ancestry, SPATCCM has also been reported in Irish, Italian, Czech, Palestinian, and Pakistani ethnicities. Herein, we report two Pakistani male siblings from a non-consanguineous marriage presented with global developmental delay associated with spastic quadriplegia, microcephaly, and infantile spasm. Since infancy, both siblings suffered from microcephaly with brain MRI demonstrating generalized atrophy of the frontal, temporal, and parietal lobes with a prominence of the subarachnoid spaces, widening of the Sylvian fissures, and enlargement of the ventricular system not compatible with the chronological age of both patients associated with thinning of the corpus callosum. Whole-exome sequencing of both affected brothers revealed novel compound heterozygous variants in the SLC1A4 gene (NM_003038) segregating from their parents. The maternal c.971delA (p.N324Tfs*29) deletion variant disturbs the transcript reading frame leading to the generation of a premature stop codon and its subsequent degradation by nonsense-mediated mRNA decay as detected through expression analysis. The paternal c.542C > T (p.S181F) missense variant was predicted deleterious via multiple in silico prediction tools as the amino acid substitution is speculated to affect the overall ASCT1 structural confirmation due to the loss of an H-bond at the core of the protein at this position which might affect its function as concluded from the simulation analysis. The presented cases expand the genetic and clinical spectrum of ASCT1 deficiency and support the importance of including SLC1A4 gene screening in infants with unexplained global neurodevelopmental delay regardless of ethnicity.
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Affiliation(s)
- Feda E. Mohamed
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mohammad A. Ghattas
- College of Pharmacy, Al Ain University, Al Ain, United Arab Emirates
- AAU Health and Biomedical Research Center, Al Ain University, Abu Dhabi, United Arab Emirates
| | - Taleb M. Almansoori
- Department of Radiology, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Mohammed Tabouni
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Ibrahim Baydoun
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Praseetha Kizhakkedath
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Anne John
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Hiba Alblooshi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Qudsia Shaukat
- Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
| | - Fatma Al-Jasmi
- Department of Genetics and Genomics, College of Medicine and Health Sciences, United Arab Emirates University, Al Ain, United Arab Emirates
- Department of Pediatrics, Tawam Hospital, Al Ain, United Arab Emirates
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8
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Pujol‐Giménez J, Mirzaa G, Blue EE, Albano G, Miller DE, Allworth A, Bennett JT, Byers PH, Chanprasert S, Chen J, Doherty D, Folta AB, Gillentine MA, Glass I, Hing A, Horike‐Pyne M, Leppig KA, Parhin A, Ranchalis J, Raskind WH, Rosenthal EA, Schwarze U, Sheppeard S, Strohbehn S, Sybert VP, Timms A, Wener M, Bamshad MJ, Hisama FM, Jarvik GP, Dipple KM, Hediger MA, Stergachis AB. Dominant-negative variant in SLC1A4 causes an autosomal dominant epilepsy syndrome. Ann Clin Transl Neurol 2023; 10:1046-1053. [PMID: 37194416 PMCID: PMC10270265 DOI: 10.1002/acn3.51786] [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: 01/30/2023] [Revised: 03/29/2023] [Accepted: 04/15/2023] [Indexed: 05/18/2023] Open
Abstract
SLC1A4 is a trimeric neutral amino acid transporter essential for shuttling L-serine from astrocytes into neurons. Individuals with biallelic variants in SLC1A4 are known to have spastic tetraplegia, thin corpus callosum, and progressive microcephaly (SPATCCM) syndrome, but individuals with heterozygous variants are not thought to have disease. We identify an 8-year-old patient with global developmental delay, spasticity, epilepsy, and microcephaly who has a de novo heterozygous three amino acid duplication in SLC1A4 (L86_M88dup). We demonstrate that L86_M88dup causes a dominant-negative N-glycosylation defect of SLC1A4, which in turn reduces the plasma membrane localization of SLC1A4 and the transport rate of SLC1A4 for L-serine.
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Affiliation(s)
- Jonai Pujol‐Giménez
- Department of Nephrology and HypertensionUniversity Hospital Bern, InselspitalBernSwitzerland
- Department of Biomedical ResearchUniversity of BernBernSwitzerland
| | - Ghayda Mirzaa
- Center for Integrative Brain ResearchSeattle Children's Research InstituteSeattleWashingtonUSA
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
| | - Elizabeth E. Blue
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
- Department of Laboratory Medicine and PathologyUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Giuseppe Albano
- Department of Nephrology and HypertensionUniversity Hospital Bern, InselspitalBernSwitzerland
- Department of Biomedical ResearchUniversity of BernBernSwitzerland
| | - Danny E. Miller
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
- Department of MedicineUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Aimee Allworth
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - James T. Bennett
- Center for Integrative Brain ResearchSeattle Children's Research InstituteSeattleWashingtonUSA
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
- Center for Developmental Biology and Regenerative MedicineSeattle Children's Research InstituteSeattleWashingtonUSA
| | - Peter H. Byers
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
- Department of MedicineUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Sirisak Chanprasert
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Jingheng Chen
- Department of Laboratory Medicine and PathologyUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Daniel Doherty
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
| | - Andrew B. Folta
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | | | - Ian Glass
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
| | - Anne Hing
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
| | - Martha Horike‐Pyne
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Kathleen A. Leppig
- Group Health CooperativeKaiser Permanente WashingtonSeattleWashingtonUSA
| | - Azma Parhin
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Jane Ranchalis
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Wendy H. Raskind
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | | | - Ulrike Schwarze
- Department of MedicineUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Sam Sheppeard
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Samuel Strohbehn
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Virginia P. Sybert
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Andrew Timms
- Center for Developmental Biology and Regenerative MedicineSeattle Children's Research InstituteSeattleWashingtonUSA
| | - Mark Wener
- Department of MedicineUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Michael J. Bamshad
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
| | - Fuki M. Hisama
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
| | - Gail P. Jarvik
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
- Genome SciencesUniversity of Washington School of MedicineSeattleWashingtonUSA
| | - Katrina M. Dipple
- Department of PediatricsUniversity of WashingtonSeattleWashingtonUSA
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
| | - Matthias A. Hediger
- Department of Nephrology and HypertensionUniversity Hospital Bern, InselspitalBernSwitzerland
- Department of Biomedical ResearchUniversity of BernBernSwitzerland
| | - Andrew B. Stergachis
- Brotman Baty Institute for Precision MedicineSeattleWashingtonUSA
- University of Washington, Institute of Public Health GeneticsSeattleWashingtonUSA
- Genome SciencesUniversity of Washington School of MedicineSeattleWashingtonUSA
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9
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Zheng S, Liu T, Li L, Liu Q, Huang C, Liang Y, Tan Y, Zhang L, Lu X. SLC1A5, unrelated to prognosis, was associated with CD8 + T-cell exclusion in the tumor microenvironment of squamous cell carcinoma. Heliyon 2023; 9:e14571. [PMID: 36950604 PMCID: PMC10025928 DOI: 10.1016/j.heliyon.2023.e14571] [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: 10/16/2022] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/17/2023] Open
Abstract
SLC1A5, short for solute carrier family 1 member 5, is a neutral amino acid transporter whose expression has been reported to be upregulated in various cancers, including esophageal squamous cell carcinoma (ESCC). Despite this, little has been described regarding the immunological involvement of SLC1A5 expression in the tumor microenvironment of ESCC. Given this, we adopted in silico analyses together with a wet lab strategy to investigate the prognostic and clinicopathological meaning of SLC1A5 expression in ESCC. In silico analyses of SLC1A5 expression data available from The Cancer Genome Atlas (TCGA) database revealed that SLC1A5 expression was unrelated to the prognosis of ESCC, which holds true when extended to other types of squamous cell carcinoma (SCC), including head and neck squamous cell carcinoma (HNSC) and lung squamous cell carcinoma (LUSC). Further analyses revealed that SLC1A5 expression correlated markedly with the infiltration density of effector CD8+ T cells in ESCC, and the same was true for HNSC and LUSC when extrapolated. As experimental confirmation, multiplexed immunofluorescent staining was undertaken to verify the correlation between SLC1A5 expression and infiltration of CD8+ T cells in a tissue microarray prepared from ESCC and matched normal control tissues. Our data confirmed that SLC1A5 expression was not associated with prognosis but was associated with the exclusion of CD8+ T cells. Taken together, all the data we curated strongly support the notion that SLC1A5 expression is associated with CD8+ T-cell exclusion in the tumor microenvironment of SCC.
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Affiliation(s)
- Shutao Zheng
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, Xinjiang Uygur Autonomous Region, Urumqi, PR China
- Clinical Medical Research Institute, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
| | - Tao Liu
- Department of Clinical Laboratory, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
| | - Lu Li
- Department of Clinical Laboratory, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
| | - Qing Liu
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, Xinjiang Uygur Autonomous Region, Urumqi, PR China
- Clinical Medical Research Institute, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
| | - Conggai Huang
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, Xinjiang Uygur Autonomous Region, Urumqi, PR China
- Department of Pathology, The Affiliated Hospital of Southwest Medical University, Luzhou, 646000, China
| | - Yan Liang
- Department of Pathology, Basic Medicine College, Xinjiang Medical University, Urumqi, 830017, China
| | - Yiyi Tan
- Clinical Medical Research Institute, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
| | - Li Zhang
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, Xinjiang Uygur Autonomous Region, Urumqi, PR China
- VIP Medicine, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
| | - Xiaomei Lu
- State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, Xinjiang Uygur Autonomous Region, Urumqi, PR China
- Clinical Medical Research Institute, First Affiliated Hospital of Xinjiang Medical University, Xinjiang Uygur Autonomous Region, Urumqi, PR China
- Corresponding author. State Key Laboratory of Pathogenesis, Prevention, Treatment of Central Asian High Incidence Diseases, Xinjiang Uygur Autonomous Region, Urumqi, PR China.
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10
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Gauthier-Coles G, Fairweather SJ, Bröer A, Bröer S. Do Amino Acid Antiporters Have Asymmetric Substrate Specificity? Biomolecules 2023; 13:biom13020301. [PMID: 36830670 PMCID: PMC9953452 DOI: 10.3390/biom13020301] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 01/31/2023] [Accepted: 02/03/2023] [Indexed: 02/10/2023] Open
Abstract
Amino acid antiporters mediate the 1:1 exchange of groups of amino acids. Whether substrate specificity can be different for the inward and outward facing conformation has not been investigated systematically, although examples of asymmetric transport have been reported. Here we used LC-MS to detect the movement of 12C- and 13C-labelled amino acid mixtures across the plasma membrane of Xenopus laevis oocytes expressing a variety of amino acid antiporters. Differences of substrate specificity between transporter paralogs were readily observed using this method. Our results suggest that antiporters are largely symmetric, equalizing the pools of their substrate amino acids. Exceptions are the antiporters y+LAT1 and y+LAT2 where neutral amino acids are co-transported with Na+ ions, favouring their import. For the antiporters ASCT1 and ASCT2 glycine acted as a selective influx substrate, while proline was a selective influx substrate of ASCT1. These data show that antiporters can display non-canonical modes of transport.
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11
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Freidman NJ, Briot C, Ryan RM. Characterizing unexpected interactions of a glutamine transporter inhibitor with members of the SLC1A transporter family. J Biol Chem 2022; 298:102178. [PMID: 35752361 PMCID: PMC9293768 DOI: 10.1016/j.jbc.2022.102178] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 06/14/2022] [Accepted: 06/19/2022] [Indexed: 11/29/2022] Open
Abstract
The solute carrier 1A family comprises a group of membrane proteins that act as dual-function amino acid transporters and chloride (Cl-) channels and includes the alanine serine cysteine transporters (ASCTs) as well as the excitatory amino acid transporters. ASCT2 is regarded as a promising target for cancer therapy, as it can transport glutamine and other neutral amino acids into cells and is upregulated in a range of solid tumors. The compound L-γ-glutamyl-p-nitroanilide (GPNA) is widely used in studies probing the role of ASCT2 in cancer biology; however, the mechanism by which GPNA inhibits ASCT2 is not entirely clear. Here, we used electrophysiology and radiolabelled flux assays to demonstrate that GPNA activates the Cl- conductance of ASCT2 to the same extent as a transported substrate, whilst not undergoing the full transport cycle. This is a previously unreported phenomenon for inhibitors of the solute carrier 1A family but corroborates a body of literature suggesting that the structural requirements for transport are distinct from those for Cl- channel formation. We also show that in addition to its currently known targets, GPNA inhibits several of the excitatory amino acid transporters. Together, these findings raise questions about the true mechanisms of its anticancer effects.
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Affiliation(s)
- Natasha J Freidman
- Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Chelsea Briot
- Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia
| | - Renae M Ryan
- Faculty of Medicine and Health, School of Medical Sciences, University of Sydney, Sydney, New South Wales, Australia.
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12
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Huttunen J, Adla SK, Markowicz-Piasecka M, Huttunen KM. Increased/Targeted Brain (Pro)Drug Delivery via Utilization of Solute Carriers (SLCs). Pharmaceutics 2022; 14:pharmaceutics14061234. [PMID: 35745806 PMCID: PMC9228667 DOI: 10.3390/pharmaceutics14061234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 02/04/2023] Open
Abstract
Membrane transporters have a crucial role in compounds’ brain drug delivery. They allow not only the penetration of a wide variety of different compounds to cross the endothelial cells of the blood–brain barrier (BBB), but also the accumulation of them into the brain parenchymal cells. Solute carriers (SLCs), with nearly 500 family members, are the largest group of membrane transporters. Unfortunately, not all SLCs are fully characterized and used in rational drug design. However, if the structural features for transporter interactions (binding and translocation) are known, a prodrug approach can be utilized to temporarily change the pharmacokinetics and brain delivery properties of almost any compound. In this review, main transporter subtypes that are participating in brain drug disposition or have been used to improve brain drug delivery across the BBB via the prodrug approach, are introduced. Moreover, the ability of selected transporters to be utilized in intrabrain drug delivery is discussed. Thus, this comprehensive review will give insights into the methods, such as computational drug design, that should be utilized more effectively to understand the detailed transport mechanisms. Moreover, factors, such as transporter expression modulation pathways in diseases that should be taken into account in rational (pro)drug development, are considered to achieve successful clinical applications in the future.
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Affiliation(s)
- Johanna Huttunen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; (J.H.); (S.K.A.)
| | - Santosh Kumar Adla
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; (J.H.); (S.K.A.)
- Institute of Organic Chemistry and Biochemistry (IOCB), Czech Academy of Sciences, Flemingovo Namesti 542/2, 160 00 Prague, Czech Republic
| | - Magdalena Markowicz-Piasecka
- Department of Pharmaceutical Chemistry, Drug Analysis and Radiopharmacy, Medical University of Lodz, ul. Muszyńskiego 1, 90-151 Lodz, Poland;
| | - Kristiina M. Huttunen
- School of Pharmacy, Faculty of Health Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; (J.H.); (S.K.A.)
- Correspondence:
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13
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Cysteine 467 of the ASCT2 Amino Acid Transporter Is a Molecular Determinant of the Antiport Mechanism. Int J Mol Sci 2022; 23:ijms23031127. [PMID: 35163050 PMCID: PMC8835248 DOI: 10.3390/ijms23031127] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/16/2022] [Accepted: 01/18/2022] [Indexed: 02/01/2023] Open
Abstract
The plasma membrane transporter ASCT2 is a well-known Na+-dependent obligatory antiporter of neutral amino acids. The crucial role of the residue C467 in the recognition and binding of the ASCT2 substrate glutamine, has been highlighted by structure/function relationship studies. The reconstitution in proteoliposomes of the human ASCT2 produced in P. pastoris is here employed to unveil another role of the C467 residue in the transport reaction. Indeed, the site-directed mutant C467A displayed a novel property of the transporter, i.e., the ability of mediating a low but measurable unidirectional transport of [3H]-glutamine. This reaction conforms to the main features of the ASCT2-mediated transport, namely the Na+-dependence, the pH dependence, the stimulation by cholesterol included in the proteoliposome membrane, and the specific inhibition by other common substrates of the reconstituted human ASCT2. Interestingly, the WT protein cannot catalyze the unidirectional transport of [3H]-glutamine, demonstrating an unspecific phenomenon. This difference is in favor of a structural conformational change between a WT and C467A mutant that triggers the appearance of the unidirectional flux; this feature has been investigated by comparing the available 3D structures in two different conformations, and two homology models built on the basis of hEAAT1 and GLTPh.
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14
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Functional and Kinetic Comparison of Alanine Cysteine Serine Transporters ASCT1 and ASCT2. Biomolecules 2022; 12:biom12010113. [PMID: 35053261 PMCID: PMC8773628 DOI: 10.3390/biom12010113] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/05/2022] [Accepted: 01/07/2022] [Indexed: 02/01/2023] Open
Abstract
Neutral amino acid transporters ASCT1 and ASCT2 are two SLC1 (solute carrier 1) family subtypes, which are specific for neutral amino acids. The other members of the SLC1 family are acidic amino acid transporters (EAATs 1–5). While the functional similarities and differences between the EAATs have been well studied, less is known about how the subtypes ASCT1 and 2 differ in kinetics and function. Here, by performing comprehensive electrophysiological analysis, we identified similarities and differences between these subtypes, as well as novel functional properties, such as apparent substrate affinities of the inward-facing conformation (in the range of 70 μM for L-serine as the substrate). Key findings were: ASCT1 has a higher apparent affinity for Na+, as well as a larger [Na+] dependence of substrate affinity compared to ASCT2. However, the general sequential Na+/substrate binding mechanism with at least one Na+ binding first, followed by amino acid substrate, followed by at least one more Na+ ion, appears to be conserved between the two subtypes. In addition, the first Na+ binding step, presumably to the Na3 site, occurs with high apparent affinity (<1 mM) in both transporters. In addition, ASCT1 and 2 show different substrate selectivities, where ASCT1 does not respond to extracellular glutamine. Finally, in both transporters, we measured rapid, capacitive charge movements upon application and removal of amino acid, due to rearrangement of the translocation equilibrium. This charge movement decays rapidly, with a time constant of 4–5 ms and recovers with a time constant in the 15 ms range after substrate removal. This places a lower limit on the turnover rate of amino acid exchange by these two transporters of 60–80 s−1.
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15
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Mazza T, Scalise M, Pappacoda G, Pochini L, Indiveri C. The involvement of sodium in the function of the human amino acid transporter ASCT2. FEBS Lett 2021; 595:3030-3041. [PMID: 34741534 DOI: 10.1002/1873-3468.14224] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 10/15/2021] [Accepted: 10/28/2021] [Indexed: 01/19/2023]
Abstract
Alanine, serine, cysteine transporter 2 (ASCT2) is a membrane amino acid transporter with relevance to human physiology and pathology, such as cancer. Notwithstanding, the study on the ASCT2 transport cycle still has unknown aspects, such as the role of Na+ in this process. We investigate this issue using recombinant hASCT2 reconstituted in proteoliposomes. Changes in the composition of purification buffers show the crucial role of Na+ in ASCT2 functionality. The transport activity is abolished when Na+ is absent or substituted by Li+ or K+ in purification buffers. By employing a Na+ fluorometric probe, we measured an inwardly directed flux of Na+ and, by combining fluorometric and radiometric assays, determined a 2Na+ : 1Gln stoichiometry. Kinetics of Na+ transport suggest that pH-sensitive residues are involved in Na+ binding/transport. Our results clarify the role of Na+ on human ASCT2 transporter activity.
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Affiliation(s)
- Tiziano Mazza
- 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
| | - Gilda Pappacoda
- Department DiBEST (Biologia, Ecologia, Scienze Della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Arcavacata di Rende, Italy
| | - Lorena Pochini
- 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.,CNR Institute of Biomembranes, Bioenergetics and Molecular Biotechnology (IBIOM), Bari, Italy
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16
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Stehantsev P, Stetsenko A, Nemchinova M, Aduri NG, Marrink SJ, Gati C, Guskov A. A structural view onto disease-linked mutations in the human neutral amino acid exchanger ASCT1. Comput Struct Biotechnol J 2021; 19:5246-5254. [PMID: 34630942 PMCID: PMC8479201 DOI: 10.1016/j.csbj.2021.09.015] [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: 07/30/2021] [Revised: 09/14/2021] [Accepted: 09/14/2021] [Indexed: 01/30/2023] Open
Abstract
The ASCT1 transporter of the SLC1 family is largely involved in equilibration of neutral amino acids' pools across the plasma membrane and plays a prominent role in the transport of both L- and D-isomers of serine, essential for the normal functioning of the central nervous system in mammals. A number of mutations in ASCT1 (E256K, G381R, R457W) have been linked to severe neurodevelopmental disorders, however in the absence of ASCT1 structure it is hard to understand their impact on substrate transport. To ameliorate that we have determined a cryo-EM structure of human ASCT1 at 4.2 Å resolution and performed functional transport assays and molecular dynamics simulations, which revealed that given mutations lead to the diminished transport capability of ASCT1 caused by instability of transporter and impeded transport cycle.
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Affiliation(s)
- Pavlo Stehantsev
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Artem Stetsenko
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Mariia Nemchinova
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Nanda Gowtham Aduri
- Department of Biological Sciences, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA, USA
| | - Siewert J. Marrink
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
| | - Cornelius Gati
- Department of Biological Sciences, Bridge Institute, USC Michelson Center for Convergent Bioscience, University of Southern California, Los Angeles, CA, USA
| | - Albert Guskov
- Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, The Netherlands
- Moscow Institute of Physics and Technology, Dolgoprudny, Russia
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