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Zou Z, Cheng Q, Zhou J, Guo C, Hadjinicolaou AV, Salio M, Liang X, Yang C, Du Y, Yao W, Wang D, Cerundolo V, Wang Q, Xia M. ATF4-SLC7A11-GSH axis mediates the acquisition of immunosuppressive properties by activated CD4 + T cells in low arginine condition. Cell Rep 2024; 43:113995. [PMID: 38527061 DOI: 10.1016/j.celrep.2024.113995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 01/21/2024] [Accepted: 03/08/2024] [Indexed: 03/27/2024] Open
Abstract
The tumor microenvironment (TME) is restricted in metabolic nutrients including the semi-essential amino acid arginine. While complete arginine deprivation causes T cell dysfunction, it remains unclear how arginine levels fluctuate in the TME to shape T cell fates. Here, we find that the 20-μM low arginine condition, representing the levels found in the plasma of patients with cancers, confers Treg-like immunosuppressive capacities upon activated T cells. In vivo mouse tumor models and human single-cell RNA-sequencing datasets reveal positive correlations between low arginine condition and intratumoral Treg accumulation. Mechanistically, low arginine-activated T cells engage in metabolic and transcriptional reprogramming, using the ATF4-SLC7A11-GSH axis, to preserve their suppressive function. These findings improve our understanding of the role of arginine in human T cell biology with potential applications for immunotherapy strategies.
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Affiliation(s)
- Ziqi Zou
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Qian Cheng
- MRC Centre for Computational Biology, MRC Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS Oxford, UK
| | - Jiajie Zhou
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Chenyao Guo
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Andreas V Hadjinicolaou
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS Oxford, UK; Early Cancer Institute, Department of Oncology, Hutchison Research Centre, University of Cambridge, CB2 0XZ Cambridge, UK
| | - Mariolina Salio
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS Oxford, UK
| | - Xinghua Liang
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou 311121, China
| | - Cuiyu Yang
- Assisted Reproduction Unit, Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Yue Du
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Weiran Yao
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
| | - Dongrui Wang
- Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou 311121, China
| | - Vincenzo Cerundolo
- MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS Oxford, UK
| | - Qingqing Wang
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; Liangzhu Laboratory, Zhejiang University Medical Center, Hangzhou 311121, China.
| | - Meng Xia
- Institute of Immunology, and Department of Dermatology and Venereology of the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China; MRC Human Immunology Unit, MRC Weatherall Institute of Molecular Medicine, University of Oxford, OX3 9DS Oxford, UK.
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Gaudet ID, Xu H, Gordon E, Cannestro GA, Lu ML, Wei J. Elevated SLC7A2 expression is associated with an abnormal neuroinflammatory response and nitrosative stress in Huntington's disease. J Neuroinflammation 2024; 21:59. [PMID: 38419038 PMCID: PMC10900710 DOI: 10.1186/s12974-024-03038-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Accepted: 02/06/2024] [Indexed: 03/02/2024] Open
Abstract
We previously identified solute carrier family 7 member 2 (SLC7A2) as one of the top upregulated genes when normal Huntingtin was deleted. SLC7A2 has a high affinity for L-arginine. Arginine is implicated in inflammatory responses, and SLC7A2 is an important regulator of innate and adaptive immunity in macrophages. Although neuroinflammation is clearly demonstrated in animal models and patients with Huntington's disease (HD), the question of whether neuroinflammation actively participates in HD pathogenesis is a topic of ongoing research and debate. Here, we studied the role of SLC7A2 in mediating the neuroinflammatory stress response in HD cells. RNA sequencing (RNA-seq), quantitative RT-PCR and data mining of publicly available RNA-seq datasets of human patients were performed to assess the levels of SLC7A2 mRNA in different HD cellular models and patients. Biochemical studies were then conducted on cell lines and primary mouse astrocytes to investigate arginine metabolism and nitrosative stress in response to neuroinflammation. The CRISPR-Cas9 system was used to knock out SLC7A2 in STHdhQ7 and Q111 cells to investigate its role in mediating the neuroinflammatory response. Live-cell imaging was used to measure mitochondrial dynamics. Finally, exploratory studies were performed using the Enroll-HD periodic human patient dataset to analyze the effect of arginine supplements on HD progression. We found that SLC7A2 is selectively upregulated in HD cellular models and patients. HD cells exhibit an overactive response to neuroinflammatory challenges, as demonstrated by abnormally high iNOS induction and NO production, leading to increased protein nitrosylation. Depleting extracellular Arg or knocking out SLC7A2 blocked iNOS induction and NO production in STHdhQ111 cells. We further examined the functional impact of protein nitrosylation on a well-documented protein target, DRP-1, and found that more mitochondria were fragmented in challenged STHdhQ111 cells. Last, analysis of Enroll-HD datasets suggested that HD patients taking arginine supplements progressed more rapidly than others. Our data suggest a novel pathway that links arginine uptake to nitrosative stress via upregulation of SLC7A2 in the pathogenesis and progression of HD. This further implies that arginine supplements may potentially pose a greater risk to HD patients.
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Affiliation(s)
- Ian D Gaudet
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Hongyuan Xu
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Emily Gordon
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Gianna A Cannestro
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Michael L Lu
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA
| | - Jianning Wei
- Department of Biomedical Science, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL, 33431, USA.
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You S, Han X, Xu Y, Yao Q. Research progress on the role of cationic amino acid transporter (CAT) family members in malignant tumors and immune microenvironment. Amino Acids 2023; 55:1213-1222. [PMID: 37572157 DOI: 10.1007/s00726-023-03313-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 08/02/2023] [Indexed: 08/14/2023]
Abstract
Amino acids are essential for the survival of all living organisms and living cells. Amino acid transporters mediate the transport and absorption of amino acids, and the dysfunction of these proteins can induce human diseases. Cationic amino acid transporters (CAT family, SLC7A1-4, and SLC7A14) are considered to be a group of transmembrane transporters, of which SLC7A1-3 are essential for arginine transport in mammals. Numerous studies have shown that CAT family-mediated arginine transport is involved in signal crosstalk between malignant tumor cells and immune cells, especially T cells. The modulation of extracellular arginine concentration has entered a number of clinical trials and achieved certain therapeutic effects. Here, we review the role of CAT family on tumor cells and immune infiltrating cells in malignant tumors and explore the therapeutic strategies to interfere with extracellular arginine concentration, to elaborate its application prospects. CAT family members may be used as biomarkers for certain cancer entities and might be included in new ideas for immunotherapy of malignant tumors.
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Affiliation(s)
- Shijing You
- Department of Obstetrics and Gynaecology, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China
| | - Xiahui Han
- Department of Obstetrics and Gynaecology, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China
| | - Yuance Xu
- Department of Obstetrics and Gynaecology, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China
| | - Qin Yao
- Department of Obstetrics and Gynaecology, The Affiliated Hospital of Qingdao University, Qingdao, 266003, Shandong, China.
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Afshinpour M, Mahdiuni H. Arginine transportation mechanism through cationic amino acid transporter 1: insights from molecular dynamics studies. J Biomol Struct Dyn 2023; 41:13580-13594. [PMID: 36762692 DOI: 10.1080/07391102.2023.2175374] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 01/28/2023] [Indexed: 02/11/2023]
Abstract
Metabolic and signaling mechanisms in mammalian cells are facilitated by the transportation of L-arginine (Arg) across the plasma membrane through cationic amino acid transporter (CAT) proteins. Due to a lack of argininosuccinate synthase (ASS) activity in various tumor cells such as acute myeloid leukemia, acute lymphocytic leukemia, and chronic lymphocytic leukemia, these tumor entities are arginine-auxotrophic and therefore depend on the uptake of the amino acid arginine. Cationic amino acid transporter-1 (CAT-1) is the leading arginine importer expressed in the aforementioned tumor entities. Hence, in the present study, to investigate the transportation mechanism of arginine in CAT-1, we performed molecular dynamics (MD) simulation methods on the modeled human CAT-1. The MM-PBSA approach was conducted to determine the critical residues interacting with arginine within the corresponding binding site of CAT-1. In addition, we found out that the water molecules have the leading role in forming the transportation channel within CAT-1. The conductive structure of CAT-1 was formed only when the water molecules were continuously distributed across the channel. Steered molecular dynamics (SMD) simulation approach showed various energy barriers against arginine transportation through CAT-1, especially while crossing the bottlenecks of the related channel. These findings at the molecular level might shed light on identifying the crucial amino acids in the binding of arginine to eukaryotic CATs and also provide fundamental insights into the arginine transportation mechanisms through CAT-1. Understanding the transportation mechanism of arginine is essential to developing CAT-1 blockers, which can be potential medications for some types of cancers.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Maral Afshinpour
- Bioinformatics Lab., Department of Biology, School of Sciences, Razi University, Kermanshah, Iran
| | - Hamid Mahdiuni
- Bioinformatics Lab., Department of Biology, School of Sciences, Razi University, Kermanshah, Iran
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5
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Ishida A, Ashihara A, Nakashima K, Katsumata M. Effects of low-protein diet and feed restriction on mRNA expression of cationic amino acid transporters in porcine skeletal muscles. Anim Sci J 2023; 94:e13861. [PMID: 37551564 DOI: 10.1111/asj.13861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 08/09/2023]
Abstract
We investigated the effects of a low-protein diet and feed restriction on the mRNA expression of cationic amino acid transporters (CATs) in the longissimus dorsi (LD), rhomboideus (RH), and biceps femoris (BF) muscles of pigs. Eighteen piglets were divided into three groups: a control (CP21%), low-protein diet (LP, CP16%), and feed-restricted diet (FR, CP21%, 76% feed intake of control pigs) groups. The expression levels of CAT-1 in the LD and BF muscles of LP pigs were higher than that of control pigs, whereas that of FR pigs showed no difference. The CAT-2A expression levels in the RH muscle of FR pigs were higher than that of control pigs. The free lysine concentrations in all muscles of LP and FR pigs were lower than that of control pigs. To examine the factors that affect CATs mRNA expression, we evaluated the effects of lysine, arginine, insulin-like growth factor-I, and dexamethasone on the expression of CATs in C2C12 myotubes. CAT-1 expression levels increased in lysine and/or arginine deprivation. We show that CAT-1 and CAT-2A expression levels in skeletal muscles differ in response to dietary treatments and CAT-1 expression in skeletal muscles appears to increase in response to low free lysine concentrations.
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Affiliation(s)
- Aiko Ishida
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Akane Ashihara
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Kazuki Nakashima
- Institute of Livestock and Grassland Science, National Agriculture and Food Research Organization, Tsukuba, Ibaraki, Japan
| | - Masaya Katsumata
- School of Veterinary Science, Azabu University, Sagamihara, Kanagawa, Japan
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Eom J, Choi J, Suh SS, Seo JB. SLC3A2 and SLC7A2 Mediate the Exogenous Putrescine-Induced Adipocyte Differentiation. Mol Cells 2022; 45:963-975. [PMID: 36572564 PMCID: PMC9794554 DOI: 10.14348/molcells.2022.0123] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 10/30/2022] [Accepted: 10/31/2022] [Indexed: 12/28/2022] Open
Abstract
Exogenous polyamines are able to induce life span and improve glucose homeostasis and insulin sensitivity. However, the effects of exogenous polyamines on adipocyte differentiation and which polyamine transporters mediate them have not been elucidated yet. Here, we identified for the first time that exogenous polyamines can clearly stimulate adipocyte differentiation through polyamine transporters, solute carrier family 3 member A2 (SLC3A2) and SLC7A1. Exogenous polyamines markedly promote 3T3-L1 adipocyte differentiation by increasing the intracellular lipid accumulation and the expression of both adipogenic and lipogenic genes in a concentration-dependent manner. In particular, exogenous putrescine mainly regulates adipocyte differentiation in the early and intermediate stages. Moreover, we have assessed the expression of polyamine transporter genes in 3T3-L1 preadipocytes and adipocytes. Interestingly, the putrescine-induced adipocyte differentiation was found to be significantly suppressed in response to a treatment with a polyamine transporter inhibitor (AMXT-1501). Furthermore, knockdown experiments using siRNA that specifically targeted SLC3A2 or SLC7A2, revealed that both SLC3A2 and SLC7A2 act as important transporters in the cellular importing of exogenous putrescine. Thus, the exogenous putrescine entering the adipocytes via cellular transporters is involved in adipogenesis through a modulation of both the mitotic clonal expansion and the expression of master transcription factors. Taken together, these results suggest that exogenous polyamines (such as putrescine) entering the adipocytes through polyamine transporters, can stimulate adipogenesis.
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Affiliation(s)
- Jin Eom
- Department of Biosciences, Mokpo National University, Muan 58554, Korea
| | - Juhyun Choi
- Department of Biomedicine, Health & Life Convergence Sciences, BK21 Four, Biomedical and Healthcare Research Institute, Mokpo National University, Muan 58554, Korea
| | - Sung-Suk Suh
- Department of Biosciences, Mokpo National University, Muan 58554, Korea
- Department of Biomedicine, Health & Life Convergence Sciences, BK21 Four, Biomedical and Healthcare Research Institute, Mokpo National University, Muan 58554, Korea
| | - Jong Bae Seo
- Department of Biosciences, Mokpo National University, Muan 58554, Korea
- Department of Biomedicine, Health & Life Convergence Sciences, BK21 Four, Biomedical and Healthcare Research Institute, Mokpo National University, Muan 58554, Korea
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Szomek M, Reinholdt P, Walther HL, Scheidt HA, Müller P, Obermaier S, Poolman B, Kongsted J, Wüstner D. Natamycin sequesters ergosterol and interferes with substrate transport by the lysine transporter Lyp1 from yeast. Biochim Biophys Acta Biomembr 2022; 1864:184012. [PMID: 35914570 DOI: 10.1016/j.bbamem.2022.184012] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 06/30/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Natamycin is a polyene macrolide, widely employed to treat fungal keratitis and other yeast infections as well as to protect food products against fungal molds. In contrast to other polyene macrolides, such as nystatin or amphotericin B, natamycin does not form pores in yeast membranes, and its mode of action is not well understood. Here, we have employed a variety of spectroscopic methods, computational modeling, and membrane reconstitution to study the molecular interactions of natamycin underlying its antifungal activity. We find that natamycin forms aggregates in an aqueous solution with strongly altered optical properties compared to monomeric natamycin. Interaction of natamycin with model membranes results in a concentration-dependent fluorescence increase which is more pronounced for ergosterol- compared to cholesterol-containing membranes up to 20 mol% sterol. Evidence for formation of specific ergosterol-natamycin complexes in the bilayer is provided. Using nuclear magnetic resonance (NMR) and electron spin resonance (ESR) spectroscopy, we find that natamycin sequesters sterols, thereby interfering with their well-known ability to order acyl chains in lipid bilayers. This effect is more pronounced for membranes containing the sterol of fungi, ergosterol, compared to those containing mammalian cholesterol. Natamycin interferes with ergosterol-dependent transport of lysine by the yeast transporter Lyp1, which we propose to be due to the sequestering of ergosterol, a mechanism that also affects other plasma membrane proteins. Our results provide a mechanistic explanation for the selective antifungal activity of natamycin, which can set the stage for rational design of novel polyenes in the future.
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Affiliation(s)
- Maria Szomek
- Department of Biochemistry and Molecular Biology, PhyLife, Physical Life Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Peter Reinholdt
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Hanna-Loisa Walther
- Department of Biochemistry and Molecular Biology, PhyLife, Physical Life Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Holger A Scheidt
- Institute for Medical Physics and Biophysics, University of Leipzig, Härtelstr. 16-18, 04107 Leipzig, Germany
| | - Peter Müller
- Department of Biology, Humboldt University Berlin, Invalidenstr. 43, 10115 Berlin, Germany
| | - Sebastian Obermaier
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 Groningen, the Netherlands
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 Groningen, the Netherlands
| | - Jacob Kongsted
- Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, DK-5230 Odense M, Denmark
| | - Daniel Wüstner
- Department of Biochemistry and Molecular Biology, PhyLife, Physical Life Sciences, University of Southern Denmark, DK-5230 Odense M, Denmark.
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Tünnermann L, Colou J, Näsholm T, Gratz R. To have or not to have: expression of amino acid transporters during pathogen infection. Plant Mol Biol 2022; 109:413-425. [PMID: 35103913 PMCID: PMC9213295 DOI: 10.1007/s11103-022-01244-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 01/16/2022] [Indexed: 06/14/2023]
Abstract
The interaction between plants and plant pathogens can have significant effects on ecosystem performance. For their growth and development, both bionts rely on amino acids. While amino acids are key transport forms of nitrogen and can be directly absorbed from the soil through specific root amino acid transporters, various pathogenic microbes can invade plant tissues to feed on different plant amino acid pools. In parallel, plants may initiate an immune response program to restrict this invasion, employing various amino acid transporters to modify the amino acid pool at the site of pathogen attack. The interaction between pathogens and plants is sophisticated and responses are dynamic. Both avail themselves of multiple tools to increase their chance of survival. In this review, we highlight the role of amino acid transporters during pathogen infection. Having control over the expression of those transporters can be decisive for the fate of both bionts but the underlying mechanism that regulates the expression of amino acid transporters is not understood to date. We provide an overview of the regulation of a variety of amino acid transporters, depending on interaction with biotrophic, hemibiotrophic or necrotrophic pathogens. In addition, we aim to highlight the interplay of different physiological processes on amino acid transporter regulation during pathogen attack and chose the LYSINE HISTIDINE TRANSPORTER1 (LHT1) as an example.
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Affiliation(s)
- Laura Tünnermann
- Department of Forest Genetics and Plant Physiology, Umeå Plant Science Centre, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
| | - Justine Colou
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden
| | - Regina Gratz
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, 90183, Umeå, Sweden.
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Dubey S, Majumder P, Penmatsa A, Sardesai AA. Topological analyses of the L-lysine exporter LysO reveal a critical role for a conserved pair of intramembrane solvent-exposed acidic residues. J Biol Chem 2021; 297:101168. [PMID: 34487760 PMCID: PMC8498466 DOI: 10.1016/j.jbc.2021.101168] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 11/16/2022] Open
Abstract
LysO, a prototypical member of the LysO family, mediates export of L-lysine (Lys) and resistance to the toxic Lys antimetabolite, L-thialysine (Thl) in Escherichia coli. Here, we have addressed unknown aspects of LysO function pertaining to its membrane topology and the mechanism by which it mediates Lys/Thl export. Using substituted cysteine (Cys) accessibility, here we delineated the membrane topology of LysO. Our studies support a model in which both the N- and C-termini of LysO are present at the periplasmic face of the membrane with a transmembrane (TM) domain comprising eight TM segments (TMSs) between them. In addition, a feature of intramembrane solvent exposure in LysO is inferred with the identification of membrane-located solvent-exposed Cys residues. Isosteric substitutions of a pair of conserved acidic residues, one E233, located in the solvent-exposed TMS7 and the other D261, in a solvent-exposed intramembrane segment located between TMS7 and TMS8, abolished LysO function in vivo. Thl, but not Lys, elicited proton release in inside-out membrane vesicles, a process requiring the presence of both E233 and D261. We postulate that Thl may be exported in antiport with H+ and that Lys may be a low-affinity export substrate. Our findings are compatible with a physiological scenario wherein in vivo LysO exports the naturally occurring antimetabolite Thl with higher affinity over the essential cellular metabolite Lys, thus affording protection from Thl toxicity and limiting wasteful export of Lys.
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Affiliation(s)
- Swati Dubey
- Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India; Graduate Studies, Manipal Academy of Higher Education, Manipal, India
| | - Puja Majumder
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Aravind Penmatsa
- Molecular Biophysics Unit, Indian Institute of Science, Bangalore, India
| | - Abhijit A Sardesai
- Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad, India.
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Fairweather SJ, Rajendran E, Blume M, Javed K, Steinhöfel B, McConville MJ, Kirk K, Bröer S, van Dooren GG. Coordinated action of multiple transporters in the acquisition of essential cationic amino acids by the intracellular parasite Toxoplasma gondii. PLoS Pathog 2021; 17:e1009835. [PMID: 34432856 PMCID: PMC8423306 DOI: 10.1371/journal.ppat.1009835] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 09/07/2021] [Accepted: 07/23/2021] [Indexed: 02/07/2023] Open
Abstract
Intracellular parasites of the phylum Apicomplexa are dependent on the scavenging of essential amino acids from their hosts. We previously identified a large family of apicomplexan-specific plasma membrane-localized amino acid transporters, the ApiATs, and showed that the Toxoplasma gondii transporter TgApiAT1 functions in the selective uptake of arginine. TgApiAT1 is essential for parasite virulence, but dispensable for parasite growth in medium containing high concentrations of arginine, indicating the presence of at least one other arginine transporter. Here we identify TgApiAT6-1 as the second arginine transporter. Using a combination of parasite assays and heterologous characterisation of TgApiAT6-1 in Xenopus laevis oocytes, we demonstrate that TgApiAT6-1 is a general cationic amino acid transporter that mediates both the high-affinity uptake of lysine and the low-affinity uptake of arginine. TgApiAT6-1 is the primary lysine transporter in the disease-causing tachyzoite stage of T. gondii and is essential for parasite proliferation. We demonstrate that the uptake of cationic amino acids by TgApiAT6-1 is ‘trans-stimulated’ by cationic and neutral amino acids and is likely promoted by an inwardly negative membrane potential. These findings demonstrate that T. gondii has evolved overlapping transport mechanisms for the uptake of essential cationic amino acids, and we draw together our findings into a comprehensive model that highlights the finely-tuned, regulated processes that mediate cationic amino acid scavenging by these intracellular parasites. The causative agent of toxoplasmosis, Toxoplasma gondii, is a versatile intracellular parasite that can proliferate within nucleated cells of warm-blooded organisms. In order to survive, T. gondii parasites must scavenge the cationic amino acids lysine and arginine from their hosts. In a previous study, we demonstrated that a plasma membrane-localized protein called TgApiAT1 facilitates the uptake of arginine into the parasite. We found that parasites lacking TgApiAT1 could proliferate when cultured in medium containing high concentrations of arginine, suggesting the existence of an additional uptake pathway for arginine. In the present study, we demonstrate that this second uptake pathway is mediated by TgApiAT6-1, a protein belonging to the same solute transporter family as TgApiAT1. We show that TgApiAT6-1 is the major lysine transporter of the parasite, and that it is critical for parasite proliferation. Furthermore, we demonstrate that TgApiAT6-1 can transport arginine into parasites under conditions in which arginine concentrations are high and lysine concentrations are comparatively lower. These data support a model for the finely-tuned acquisition of essential cationic amino acids that involves multiple transporters, and which likely contributes to these parasites being able to survive and proliferate within a wide variety of host cell types.
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Affiliation(s)
- Stephen J. Fairweather
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- * E-mail: (SJF); (GGvD)
| | - Esther Rajendran
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Martin Blume
- Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
- Robert Koch Institute, Berlin, Germany
| | - Kiran Javed
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Birte Steinhöfel
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- Humboldt University Berlin, Berlin, Germany
| | - Malcolm J. McConville
- Department of Biochemistry and Molecular Biology and the Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, Victoria, Australia
| | - Kiaran Kirk
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Stefan Bröer
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
| | - Giel G. van Dooren
- Research School of Biology, Australian National University, Canberra, Australian Capital Territory, Australia
- * E-mail: (SJF); (GGvD)
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11
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Abstract
PQLC2, a lysosomal cationic amino acid transporter, also serves as a sensor that responds to scarcity of its substrates by recruiting a protein complex composed of C9orf72, SMCR8, and WDR41 to the surface of lysosomes. This protein complex controls multiple aspects of lysosome function. Although it is known that this response to changes in cationic amino acid availability depends on an interaction between PQLC2 and WDR41, the underlying mechanism for the regulated interaction is not known. In this study, we present evidence that the WDR41-PQLC2 interaction is mediated by a short peptide motif in a flexible loop that extends from the WDR41 β-propeller and inserts into a cavity presented by the inward-facing conformation of PQLC2. The data support a transceptor model wherein conformational changes in PQLC2 related to substrate transport regulate the availability of the WDR41-binding site on PQLC2 and mediate recruitment of the WDR41-SMCR8-C9orf72 complex to the surface of lysosomes.
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Affiliation(s)
- Gabriel Talaia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Joseph Amick
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Shawn M Ferguson
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510;
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT 06510
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12
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Xiao J, Wang D, Wang L, Jiang Y, Xue L, Sui S, Wang J, Guo C, Wang R, Wang J, Li N, Fan H, Lv M. Increasing L-lysine production in Corynebacterium glutamicum by engineering amino acid transporters. Amino Acids 2020; 52:1363-1374. [PMID: 33021685 DOI: 10.1007/s00726-020-02893-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Accepted: 09/17/2020] [Indexed: 12/28/2022]
Abstract
Corynebacterium glutamicum has a long and successful history in the biotechnological production of L-lysine. Besides the adjustment of metabolic pathways, intracellular and extracellular transport systems are critical for the cellular metabolism of L-lysine or its by-products. Here, three amino acid transmembrane transporters, namely, GluE, BrnE/BrnF, and LysP, which are widely present in C. glutamicum strains, were each investigated by gene knockout. In comparison with that in the wild-type strain, the yield of L-lysine increased by 9.0%, 12.3%, and 10.0% after the deletion of the gluE, brnE/brnF, and lysP genes, respectively, in C. glutamicum 23,604. Moreover, the amount of by-product amino acids decreased significantly when the gluE and brnE/brnF genes were deleted. It was also demonstrated that there was no effect on the growth of the strain when the gluE or lysP gene was deleted, whereas the biomass of C. glutamicum WL1702 (ΔbrnE/ΔbrnF) in the fermentation medium was significantly reduced in comparison with that of the wild type. These results also provide useful information for enhancing the production of L-lysine or other amino acids by C. glutamicum.
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Affiliation(s)
- Jing Xiao
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
| | - Datao Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
| | - Lei Wang
- School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, 214122, Jiangsu, People's Republic of China
| | - Yanjun Jiang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
| | - Le Xue
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
| | - Songsen Sui
- Zhucheng Dongxiao Biotechnology Co., Ltd, Xinxing Town, Zhucheng, 262200, Shandong, People's Republic of China
| | - Jianbin Wang
- Zhucheng Dongxiao Biotechnology Co., Ltd, Xinxing Town, Zhucheng, 262200, Shandong, People's Republic of China
| | - Chuanzhuang Guo
- Zhucheng Dongxiao Biotechnology Co., Ltd, Xinxing Town, Zhucheng, 262200, Shandong, People's Republic of China
| | - Ruiming Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
| | - Junqing Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China.
| | - Nan Li
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, 300457, People's Republic of China.
| | - Han Fan
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
| | - Maocui Lv
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology), Jinan, 250353, Shandong, People's Republic of China
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13
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van‘t Klooster JS, Bianchi F, Doorn RB, Lorenzon M, Lusseveld JH, Punter CM, Poolman B. Extracellular loops matter - subcellular location and function of the lysine transporter Lyp1 from Saccharomyces cerevisiae. FEBS J 2020; 287:4401-4414. [PMID: 32096906 PMCID: PMC7687128 DOI: 10.1111/febs.15262] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/05/2020] [Accepted: 02/24/2020] [Indexed: 12/01/2022]
Abstract
Yeast amino acid transporters of the APC superfamily are responsible for the proton motive force-driven uptake of amino acids into the cell, which for most secondary transporters is a reversible process. The l-lysine proton symporter Lyp1 of Saccharomyces cerevisiae is special in that the Michaelis constant from out-to-in transport ( K m out → in ) is much lower than K m in → out , which allows accumulation of l-lysine to submolar concentration. It has been proposed that high intracellular lysine is part of the antioxidant mechanism of the cell. The molecular basis for the unique kinetic properties of Lyp1 is unknown. We compared the sequence of Lyp1 with APC para- and orthologues and find structural features that set Lyp1 apart, including differences in extracellular loop regions. We screened the extracellular loops by alanine mutagenesis and determined Lyp1 localization and activity and find positions that affect either the localization or activity of Lyp1. Half of the affected mutants are located in the extension of extracellular loop 3 or in a predicted α-helix in extracellular loop 4. Our data indicate that extracellular loops not only connect the transmembrane helices but also serve functionally important roles.
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Affiliation(s)
- Joury S. van‘t Klooster
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
| | - Frans Bianchi
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
| | - Ruben B. Doorn
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
| | - Mirco Lorenzon
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
| | - Jarnick H. Lusseveld
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
| | - Christiaan M. Punter
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
| | - Bert Poolman
- Department of BiochemistryGroningen Biomolecular Sciences and Biotechnology InstituteUniversity of GroningenThe Netherlands
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14
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Guo N, Hu J, Yan M, Qu H, Luo L, Tegeder M, Xu G. Oryza sativa Lysine-Histidine-type Transporter 1 functions in root uptake and root-to-shoot allocation of amino acids in rice. Plant J 2020; 103:395-411. [PMID: 32159895 DOI: 10.1111/tpj.14742] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 02/02/2020] [Accepted: 02/11/2020] [Indexed: 05/03/2023]
Abstract
In agricultural soils, amino acids can represent vital nitrogen (N) sources for crop growth and yield. However, the molecular mechanisms underlying amino acid uptake and allocation are poorly understood in crop plants. This study shows that rice (Oryza sativa L.) roots can acquire aspartate at soil concentration, and that japonica subspecies take up this acidic amino acid 1.5-fold more efficiently than indica subspecies. Genetic association analyses with 68 representative japonica or indica germplasms identified rice Lysine-Histidine-type Transporter 1 (OsLHT1) as a candidate gene associated with the aspartate uptake trait. When expressed in yeast, OsLHT1 supported cell growth on a broad spectrum of amino acids, and effectively transported aspartate, asparagine and glutamate. OsLHT1 is localized throughout the rice root, including root hairs, epidermis, cortex and stele, and to the leaf vasculature. Knockout of OsLHT1 in japonica resulted in reduced root uptake of amino acids. Furthermore, in 15 N-amino acid-fed mutants versus wild-type, a higher percentage of 15 N remained in roots instead of being allocated to the shoot. 15 N-ammonium uptake and subsequently the delivery of root-synthesized amino acids to Oslht1 shoots were also significantly decreased, which was accompanied by reduced shoot growth. These results together provide evidence that OsLHT1 functions in both root uptake and root to shoot allocation of a broad spectrum of amino acids in rice.
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Affiliation(s)
- Nan Guo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Jinqi Hu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Ming Yan
- Shanghai Agrobiological Gene Center, Shanghai, 201106, China
| | - Hongye Qu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Le Luo
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
| | - Mechthild Tegeder
- School of Biological Sciences, Washington State University, Pullman, WA, 99164, USA
| | - Guohua Xu
- State Key Laboratory of Crop Genetics and Germplasm Enhancement, MOA Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Nanjing Agricultural University, Nanjing, 210095, China
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15
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Abstract
A direct inhibiting effect of NO on the function of CAT-1 and -2A has been postulated to occur via nitrosylation of cysteine residues in the transporters. Neither the NO donor SNAP nor a mixture of SIN-1 and Spermine NONOate, that generates the strong nitrosating agent N2O3, reduced CAT-mediated L-arginine transport. Direct nitros(yl)ation does either not occur in CATs or does not affect their transport function. A regulatory effect of NO or nitrosating agents on CAT-mediated transport under physiological conditions seems, therefore, unlikely.
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Affiliation(s)
- Anastasia J Hobbach
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany
| | - Ellen I Closs
- Department of Pharmacology, University Medical Center of the Johannes Gutenberg University Mainz, Langenbeckstraße 1, 55131, Mainz, Germany.
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16
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Wang X, Yang G, Shi M, Hao D, Wei Q, Wang Z, Fu S, Su Y, Xia J. Disruption of an amino acid transporter LHT1 leads to growth inhibition and low yields in rice. BMC Plant Biol 2019; 19:268. [PMID: 31221084 PMCID: PMC6584995 DOI: 10.1186/s12870-019-1885-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Accepted: 06/13/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Research on plant amino acid transporters was mainly performed in Arabidopsis, while our understanding of them is generally scant in rice. OsLHT1 (Lysine/Histidine transporter) has been previously reported as a histidine transporter in yeast, but its substrate profile and function in planta are unclear. The aims of this study are to analyze the substrate selectivity of OsLHT1 and influence of its disruption on rice growth and fecundity. RESULTS Substrate selectivity of OsLHT1 was analyzed in Xenopus oocytes using the two-electrode voltage clamp technique. The results showed that OsLHT1 could transport a broad spectrum of amino acids, including basic, neutral and acidic amino acids, and exhibited a preference for neutral and acidic amino acids. Two oslht1 mutants were generated using CRISPR/Cas9 genome-editing technology, and the loss-of-function of OsLHT1 inhibited rice root and shoot growth, thereby markedly reducing grain yields. QRT-PCR analysis indicated that OsLHT1 was expressed in various rice organs, including root, stem, flag leaf, flag leaf sheath and young panicle. Transient expression in rice protoplast suggested OsLHT1 was localized to the plasma membrane, which is consistent with its function as an amino acid transporter. CONCLUSIONS Our results indicated that OsLHT1 is an amino acid transporter with wide substrate specificity and with preference for neutral and acidic amino acids, and disruption of OsLHT1 function markedly inhibited rice growth and fecundity.
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Affiliation(s)
- Xiaohu Wang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
| | - Guangzhe Yang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
| | - Mingxing Shi
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
| | - Dongli Hao
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, 210008 China
| | - Qiuxing Wei
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
| | - Zhigang Wang
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
| | - Shan Fu
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
| | - Yanhua Su
- State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, No. 71, East Beijing Road, Nanjing, 210008 China
| | - Jixing Xia
- State Key Laboratory of Conservation and Utilization of Subtropical Agro-bioresources, College of Life Science and Technology, Guangxi University, Nanning, 530005 China
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17
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Pawar H, Puri M, Fischer Weinberger R, Madhubala R, Zilberstein D. The arginine sensing and transport binding sites are distinct in the human pathogen Leishmania. PLoS Negl Trop Dis 2019; 13:e0007304. [PMID: 31017889 PMCID: PMC6502434 DOI: 10.1371/journal.pntd.0007304] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2018] [Revised: 05/06/2019] [Accepted: 03/14/2019] [Indexed: 01/08/2023] Open
Abstract
The intracellular protozoan parasite Leishmania donovani causes human visceral leishmaniasis. Intracellular L. donovani that proliferate inside macrophage phagolysosomes compete with the host for arginine, creating a situation that endangers parasite survival. Parasites have a sensor that upon arginine deficiency activates an Arginine Deprivation Response (ADR). L. donovani transport arginine via a high-affinity transporter (LdAAP3) that is rapidly up-regulated by ADR in intracellular amastigotes. To date, the sensor and its ligand have not been identified. Here, we show that the conserved amidino group at the distal cap of the arginine side chain is the ligand that activates ADR, in both promastigotes and intracellular amastigotes, and that arginine sensing and transport binding sites are distinct in L. donovani. Finally, upon addition of arginine and analogues to deprived cells, the amidino ligand activates rapid degradation of LdAAP3. This study provides the first identification of an intra-molecular ligand of a sensor that acts during infection. Leishmania donovani, the causative agent of visceral leishmaniasis, leads a digenetic life cycle as a flagellated promastigote in the vector sandfly and aflagellated amastigote within phagolysosomes of infected macrophages. Arginine is an essential amino acid for Leishmania which possesses a high specificity arginine transporter (LdAAP3), a protein that imports the amino acid into parasite cells. Arginine is primarily utilized in de novo protein synthesis and for biosynthesis of trypanothione via the polyamine pathway. It was previously reported by our group that L. donovani senses lack of arginine in the surrounding micro environment and activates a unique arginine deprivation response (ADR) pathway, thus upregulating the expression of LdAAP3 as well as other transporters. In the present study, we identified the region on the arginine molecule which is the ligand that activates ADR. We show that the conserved amidino group at the distal cap of the arginine side chain is the ligand that activates/suppresses ADR. Using arginine analogues that contain this group we observed that arginine sensing and transport are distinct in L. donovani, both in axenic promastigotes and intracellular amastigotes. Additionally, the arginine sensor responds to both arginine starvation and sufficiency.
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Affiliation(s)
- Harsh Pawar
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Madhu Puri
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | | | - Rentala Madhubala
- School of Life Sciences, Jawaharlal Nehru University, New Delhi, India
| | - Dan Zilberstein
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
- * E-mail:
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18
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Tan J, Zhang F, Karcher D, Bock R. Engineering of high-precision base editors for site-specific single nucleotide replacement. Nat Commun 2019; 10:439. [PMID: 30683865 PMCID: PMC6347625 DOI: 10.1038/s41467-018-08034-8] [Citation(s) in RCA: 94] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2018] [Accepted: 12/12/2018] [Indexed: 12/17/2022] Open
Abstract
RNA-guided nucleases of the CRISPR/Cas type can be repurposed as programmable nucleotide deaminases to mediate targeted nucleotide substitutions. Such base editors have enormous potential in genome editing, gene therapy and precision breeding. However, current editors suffer from limited specificity in that they edit different and/or multiple bases within a larger sequence window. Using cytidine deaminase base editors that elicit C-to-T mutations, we show here that high editing precision can be achieved by engineering the connection between the deaminase domain and the Cas domain of the editor. By systematically testing different linker sequences and removing non-essential sequences from the deaminase, we obtain high-precision base editors with narrow activity windows that can selectively edit a single cytidine at a specific position with high accuracy and efficiency. These base editors will enable the use of genome editing in applications where single-nucleotide changes are required and off-target editing of adjacent nucleotides is not tolerable.
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Affiliation(s)
- Junjie Tan
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Fei Zhang
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
- National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, 430070, Wuhan, Hubei, China
| | - Daniel Karcher
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany
| | - Ralph Bock
- Max-Planck-Institut für Molekulare Pflanzenphysiologie, Am Mühlenberg 1, 14476, Potsdam-Golm, Germany.
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19
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Abstract
Budding yeast Saccharomyces cerevisiae is an ideal model organism to study membrane trafficking pathways. The ESCRT (endosomal sorting complexes required for transport) pathway was first identified in this organism. Upon recognition of endocytosed ubiquitinated membrane proteins at endosomes, ESCRTs assemble at these organelles to catalyze the biogenesis of multivesicular bodies (MVBs). Formation of MVBs leads to the trafficking of these membrane proteins to vacuoles for degradation. Here, we describe genetic and biochemical approaches to study ESCRT function. We outline in vivo endocytosis assays using two model cargoes in Saccharomyces cerevisiae and also describe an in vitro approach to analyze ESCRT-III polymerization on lipid monolayers.
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Affiliation(s)
- Sudeep Banjade
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Shaogeng Tang
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
- Department of Biochemistry, Stanford University, Stanford, CA, USA
| | - Scott D Emr
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA.
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20
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Chen Y, Yan Y, Ren ZF, Ganeteg U, Yao GK, Li ZL, Huang T, Li JH, Tian YQ, Lin F, Xu HH. AtLHT1 Transporter Can Facilitate the Uptake and Translocation of a Glycinergic-Chlorantraniliprole Conjugate in Arabidopsis thaliana. J Agric Food Chem 2018; 66:12527-12535. [PMID: 30403859 DOI: 10.1021/acs.jafc.8b03591] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Understanding of the transporters involved in the uptake and translocation of agrochemicals in plants could provide an opportunity to guide pesticide to the site of insect feeding. The product of Arabidopsis thaliana gene AtLHT1 makes a major contribution to the uptake into the roots of free amino acids and some of their derivatives. Here, a chlorantraniliprole-glycine conjugate (CAP-Gly-1) was tested for its affinity to AtLHT1 both in planta and in vitro. Seedlings deficient in AtLHT1 exhibited a reduction with respect to both the uptake and root-to-shoot transfer of CAP-Gly-1; plants in which AtLHT1 was constitutively expressed were more effective than wild type in term of their root uptake of CAP-Gly-1. Protoplast patch clamping showed that the presence in the external medium of CAP-Gly-1 was able to induce AtLHT1 genotype-dependent inward currents. An electrophysiology-based experiment carried out in Xenopus laevis oocytes expressing AtLHT1 showed that AtLHT1 had a high in vitro affinity for CAP-Gly-1. The observations supported the possibility of exploiting AtLHT1 as a critical component of a novel delivery system for amino acid-based pesticide conjugates.
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Affiliation(s)
- Yan Chen
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Ying Yan
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Zhan-Fu Ren
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Ulrika Ganeteg
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology , Swedish University of Agricultural Sciences (SLU) , SE-901 83 Umeå , Sweden
| | - Guang-Kai Yao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Zi-Lin Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Tian Huang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Jia-Hui Li
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Yong-Qing Tian
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Fei Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
| | - Han-Hong Xu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou , 510642 Guangdong , China
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21
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Lee JS, Adler L, Karathia H, Carmel N, Rabinovich S, Auslander N, Keshet R, Stettner N, Silberman A, Agemy L, Helbling D, Eilam R, Sun Q, Brandis A, Malitsky S, Itkin M, Weiss H, Pinto S, Kalaora S, Levy R, Barnea E, Admon A, Dimmock D, Stern-Ginossar N, Scherz A, Nagamani SCS, Unda M, Wilson DM, Elhasid R, Carracedo A, Samuels Y, Hannenhalli S, Ruppin E, Erez A. Urea Cycle Dysregulation Generates Clinically Relevant Genomic and Biochemical Signatures. Cell 2018; 174:1559-1570.e22. [PMID: 30100185 DOI: 10.1016/j.cell.2018.07.019] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 05/21/2018] [Accepted: 07/12/2018] [Indexed: 01/02/2023]
Abstract
The urea cycle (UC) is the main pathway by which mammals dispose of waste nitrogen. We find that specific alterations in the expression of most UC enzymes occur in many tumors, leading to a general metabolic hallmark termed "UC dysregulation" (UCD). UCD elicits nitrogen diversion toward carbamoyl-phosphate synthetase2, aspartate transcarbamylase, and dihydrooratase (CAD) activation and enhances pyrimidine synthesis, resulting in detectable changes in nitrogen metabolites in both patient tumors and their bio-fluids. The accompanying excess of pyrimidine versus purine nucleotides results in a genomic signature consisting of transversion mutations at the DNA, RNA, and protein levels. This mutational bias is associated with increased numbers of hydrophobic tumor antigens and a better response to immune checkpoint inhibitors independent of mutational load. Taken together, our findings demonstrate that UCD is a common feature of tumors that profoundly affects carcinogenesis, mutagenesis, and immunotherapy response.
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Affiliation(s)
- Joo Sang Lee
- Cancer Data Science Lab, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; Center for Bioinformatics and Computational Biology, University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, College Park, MD 20742, USA
| | - Lital Adler
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Hiren Karathia
- Center for Bioinformatics and Computational Biology, University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, College Park, MD 20742, USA
| | - Narin Carmel
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Shiran Rabinovich
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Noam Auslander
- Cancer Data Science Lab, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; Center for Bioinformatics and Computational Biology, University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, College Park, MD 20742, USA
| | - Rom Keshet
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Noa Stettner
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel; Department of Veterinary Resources, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Alon Silberman
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Lilach Agemy
- Department of Plant and Environmental Science, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | | | - Raya Eilam
- Department of Veterinary Resources, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Qin Sun
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA
| | - Alexander Brandis
- Life Sciences Core Facilities, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Sergey Malitsky
- Life Sciences Core Facilities, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Maxim Itkin
- Life Sciences Core Facilities, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Hila Weiss
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Sivan Pinto
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Shelly Kalaora
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Ronen Levy
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Eilon Barnea
- Faculty of Biology, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - Arie Admon
- Faculty of Biology, Technion - Israel Institute of Technology, 3200003 Haifa, Israel
| | - David Dimmock
- Rady Children's Institute for Genomic Medicine, San Diego, CA 92123, USA
| | - Noam Stern-Ginossar
- Department of Molecular Genetics, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Avigdor Scherz
- Department of Veterinary Resources, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Sandesh C S Nagamani
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA; Texas Children's Hospital, Houston, TX 77030, USA
| | - Miguel Unda
- Department of Urology, Basurto University Hospital, 48013 Bilbao, Spain; CIBERONC, Madrid, Spain
| | - David M Wilson
- Laboratory of Molecular Gerontology, National Institute on Aging, Intramural Research Program, NIH, 251 Bayview Blvd., Baltimore, MD 21224, USA
| | - Ronit Elhasid
- Sackler Faculty of Medicine, Department of Pediatric Hemato Oncology, Sourasky Medical Center, Tel Aviv University, 6997801 Tel Aviv, Israel
| | - Arkaitz Carracedo
- CIBERONC, Madrid, Spain; CIC bioGUNE, Bizkaia Technology Park, 801 Building, 48160 Derio, Spain; Ikerbasque, Basque Foundation for Science, Bilbao, Spain; Biochemistry and Molecular Biology Department, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Yardena Samuels
- Department of Molecular Cell Biology, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Sridhar Hannenhalli
- Center for Bioinformatics and Computational Biology, University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, College Park, MD 20742, USA
| | - Eytan Ruppin
- Cancer Data Science Lab, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA; Center for Bioinformatics and Computational Biology, University of Maryland Institute for Advanced Computer Studies, Department of Computer Science, University of Maryland, College Park, MD 20742, USA; Schools of Medicine and Computer Science, Tel Aviv University, 6997801 Tel Aviv, Israel.
| | - Ayelet Erez
- Department of Biological Regulation, Weizmann Institute of Science, 7610001 Rehovot, Israel.
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Jiang X, Xie Y, Ren Z, Ganeteg U, Lin F, Zhao C, Xu H. Design of a New Glutamine-Fipronil Conjugate with α-Amino Acid Function and Its Uptake by A. thaliana Lysine Histidine Transporter 1 ( AtLHT1). J Agric Food Chem 2018; 66:7597-7605. [PMID: 29944366 DOI: 10.1021/acs.jafc.8b02287] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Creating novel pesticides with phloem mobility is essential for controlling insects in vascular tissue and root, and conjugating existing pesticides with amino acid is an effective approach. In order to obtain a highly phloem-mobile candidate for efficient pesticides, an electro-neutral l-glutamine-fipronil conjugate (l-GlnF) retaining α-amino acid function was designed and synthesized to fit the substrate specificity of an amino acid transporter. Cotyledon uptake and phloem loading tests with Ricinus communis have verified that l-GlnF was phloem mobile, and its phloem mobility was higher than that of its enantiomer d-GlnF and other previously reported amino acid-fipronil conjugates. Inhibition experiments then suggested that the uptake of l-GlnF was, at least partially, mediated by an active transport mechanism. This inference was further strengthened by assimilation experiments with Xenopus oocytes and genetically modified Arabidopsis thaliana, which showed a direct correlation between the uptake of l-GlnF and the expression of amino acid transporter AtLHT1. Thus, conjugation with l-Gln appears to be a potential strategy to ensure the uptake of pesticides via an endogenous amino acid transport system.
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Affiliation(s)
- Xunyuan Jiang
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou 510642 , China
| | - Yun Xie
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou 510642 , China
| | - Zhanfu Ren
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou 510642 , China
| | - Ulrika Ganeteg
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology , Swedish University of Agricultural Sciences , SE-901 83 Umeå , Sweden
| | - Fei Lin
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou 510642 , China
| | - Chen Zhao
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou 510642 , China
| | - Hanhong Xu
- State Key Laboratory for Conservation and Utilization of Subtropical Agro-Bioresources and Key Laboratory of Natural Pesticide and Chemical Biology, Ministry of Education , South China Agricultural University , Guangzhou 510642 , China
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Crouse MS, McLean KJ, Greseth NP, Crosswhite MR, Pereira NN, Ward AK, Reynolds LP, Dahlen CR, Neville BW, Borowicz PP, Caton JS. Maternal nutrition and stage of early pregnancy in beef heifers: Impacts on expression of glucose, fructose, and cationic amino acid transporters in utero-placental tissues. J Anim Sci 2018; 95:5563-5572. [PMID: 29293768 DOI: 10.2527/jas2017.1983] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
We hypothesized that maternal nutrition and day of gestation would impact utero-placental mRNA expression of the nutrient transporters , , , , and in beef heifers. Crossbred Angus heifers (n = 49) were estrous synchronized, bred via AI, assigned to nutritional treatment (CON = 100% of NRC requirements for 0.45 kg/d gain and RES = 60% of CON) and ovariohysterectomized on d 16, 34, or 50 of gestation (n = 6 to 9/d); Non-bred, non-pregnant (NB-NP) controls were fed the CON diet, not bred, and were ovariohysterectomized on d 16 of the synchronized estrous cycle = 6). The resulting arrangement of treatments was a 2 × 3 factorial + 1 (CON vs. RES × d 16, 34, or 50 + NB-NP controls). Caruncle (CAR), intercaruncular endometrium (ICAR), and fetal membranes (FM [chorioallantois]), were obtained from the pregnant uterine horn (the uterine horn containing the conceptus) immediately after ovariohysterectomy. On d 50 cotyledons (COT), intercotyledonary placenta (ICOT) and amnion (AMN) were also collected. Relative expression of nutrient transporters was determined for each tissue utilizing NB-NP-CAR and NB-NP-ICAR tissues as the baseline. For FM, NB-NP endometrium served as the baseline. There was no interaction of day × treatment ( ≥ 0.20) for any genes in CAR. However, CAR expression of was greater ( < 0.01) on d 16 compared with d 34 and 50, and , , and were greater ( ≤ 0.05) on d 34 compared with d 16 and 50. In ICAR, was the only gene to be influenced by the day × treatment interaction ( = 0.01), being greater in d 50 CON compared with d 34 CON and d 16 and 50 RES. In ICAR, expression of was greater ( < 0.01) on d 16 compared with d 34, and expression of was greater ( < 0.01) on d 34 and 50 compared with d 16. In FM, expression of was greater ( = 0.04) on d 16 compared with d 50 of gestation, and expression of was greater ( < 0.01) on d 34 and 50 compared with d 16. On d 50, expression of , , and expression were all greater ( < 0.05) in AMN compared with COT and ICOT, and expression of was greater ( < 0.01) in ICOT compared with COT and AMN. These data indicate that day was a more influential factor for mRNA expression of utero-placental glucose and cationic AA transporters than maternal nutritional status in heifers during early pregnancy.
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Dadone-Montaudié B, Ambrosetti D, Dufour M, Darcourt J, Almairac F, Coyne J, Virolle T, Humbert O, Burel-Vandenbos F. [18F] FDOPA standardized uptake values of brain tumors are not exclusively dependent on LAT1 expression. PLoS One 2017; 12:e0184625. [PMID: 28937983 PMCID: PMC5609741 DOI: 10.1371/journal.pone.0184625] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2017] [Accepted: 08/28/2017] [Indexed: 11/18/2022] Open
Abstract
[18F]-FDOPA is a labeled amino acid (AA) analog used for positron emission tomography (PET) which is gaining increasing interest in the evaluation of brain tumors (BT). The AA-transporter LAT1 has been shown to be involved in [18F]-FDOPA uptake. The aim of this study was to determine whether the [18F]-FDOPA uptake was correlated with level of LAT1 expression in BT. Twenty-eight BT (including 19 gliomas and 9 metastases) were investigated by [18F]-FDOPA-PET prior to surgery and by anti-LAT1 immunohistochemistry on surgical specimens. The quantitative [18F]-FDOPA measured parameters were SUVmax, SUVmean and SUVpeak. LAT1 expression was quantified using a score (0 to 400). A significant [18F]-FDOPA uptake was associated with a LAT1 score ≥ 100 (p = 0.02) but there was no linear correlation between intensity of [18F]-FDOPA uptake and score of LAT1 expression whatever the parameters considered. LAT1 expression alone is not sufficient to explain variation of intensity of [18F]-FDOPA uptake in BT.
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Affiliation(s)
- Bérengère Dadone-Montaudié
- Department of Pathology, University Hospital, Nice, France
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
| | - Damien Ambrosetti
- Department of Pathology, University Hospital, Nice, France
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
| | - Maxime Dufour
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
- Department of Nuclear Medicine, Centre Antoine Lacassagne, Nice, France
- TIRO–UMR E 4320, University of Nice-Sophia-Antipolis, Nice, France
| | - Jacques Darcourt
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
- Department of Nuclear Medicine, Centre Antoine Lacassagne, Nice, France
- TIRO–UMR E 4320, University of Nice-Sophia-Antipolis, Nice, France
| | - Fabien Almairac
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
- Department of Neurosurgery, University Hospital, Nice, France
- UMR CNRS 7277-UMR INSERM 1091, Institute of Biology Valrose, University of Nice-Sophia-Antipolis, Nice, France
| | - John Coyne
- Department of Pathology, University Hospital, Nice, France
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
| | - Thierry Virolle
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
- UMR CNRS 7277-UMR INSERM 1091, Institute of Biology Valrose, University of Nice-Sophia-Antipolis, Nice, France
| | - Olivier Humbert
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
- Department of Nuclear Medicine, Centre Antoine Lacassagne, Nice, France
- TIRO–UMR E 4320, University of Nice-Sophia-Antipolis, Nice, France
| | - Fanny Burel-Vandenbos
- Department of Pathology, University Hospital, Nice, France
- UCA, Université Côte d’Azur, Nice-Sophia-Antipolis, France
- UMR CNRS 7277-UMR INSERM 1091, Institute of Biology Valrose, University of Nice-Sophia-Antipolis, Nice, France
- * E-mail:
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25
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Moretti ML, Alárcon-Reverte R, Pearce S, Morran S, Hanson BD. Transcription of putative tonoplast transporters in response to glyphosate and paraquat stress in Conyza bonariensis and Conyza canadensis and selection of reference genes for qRT-PCR. PLoS One 2017; 12:e0180794. [PMID: 28700644 PMCID: PMC5507266 DOI: 10.1371/journal.pone.0180794] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 06/21/2017] [Indexed: 02/03/2023] Open
Abstract
Herbicide resistance is a challenge for modern agriculture further complicated by cases of resistance to multiple herbicides. Conyza bonariensis and Conyza canadensis are invasive weeds of field crops, orchards, and non-cropped areas in many parts of the world. In California, USA, Conyza populations resistant to the herbicides glyphosate and paraquat have recently been described. Although the mechanism conferring resistance to glyphosate and paraquat in these species was not elucidated, reduced translocation of these herbicides was observed under experimental conditions in both species. Glyphosate and paraquat resistance associated with reduced translocation are hypothesized to be a result of sequestration of herbicides into the vacuole, with the possible involvement of over-expression of genes encoding tonoplast transporters of ABC-transporter families in cases of glyphosate resistance or cationic amino acid transporters (CAT) in cases of paraquat resistance. However, gene expression in response to herbicide treatment has not been studied in glyphosate and paraquat resistant populations. In the current study, we evaluated the transcript levels of genes possibly involved in resistance using real-time PCR. First, we evaluated eight candidate reference genes following herbicide treatment and selected three genes that exhibited stable expression profiles; ACTIN, HEAT-SHOCK-PROTEIN-70, and CYCLOPHILIN. The reference genes identified here can be used for further studies related to plant-herbicide interactions. We used these reference genes to assay the transcript levels of EPSPS, ABC transporters, and CAT in response to herbicide treatment in susceptible and resistant Conyza spp. lines. No transcription changes were observed in EPSPS or CAT genes after glyphosate or paraquat treatment, suggesting that these genes are not involved in the resistance mechanism. Transcription of the two ABC transporter genes increased following glyphosate treatment in all Conyza spp. lines. Transcription of ABC transporters also increased after paraquat treatment in all three lines of C. bonariensis. However, in C. canadensis, paraquat treatment increased transcription of only one ABC transporter gene in the susceptible line. The increase in transcription of ABC transporters after herbicide treatment is likely a stress response based on similar response observed across all Conyza lines regardless of resistance or sensitivity to glyphosate or paraquat, thus these genes do not appear to be directly involved in the mechanism of resistance in Conyza spp.
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Affiliation(s)
- Marcelo L. Moretti
- Department of Plant Sciences, University of California, Davis, California, United States of America
- Department of Horticulture, Oregon State University, Corvallis, Oregon, United States of America
| | - Rocio Alárcon-Reverte
- Department of Plant Sciences, University of California, Davis, California, United States of America
| | - Stephen Pearce
- Department of Soil and Crop Sciences, Colorado State University, Fort Collins, Colorado, United States of America
| | - Sarah Morran
- Department of Plant Sciences, University of California, Davis, California, United States of America
| | - Bradley D. Hanson
- Department of Plant Sciences, University of California, Davis, California, United States of America
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26
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Ganeteg U, Ahmad I, Jämtgård S, Aguetoni-Cambui C, Inselsbacher E, Svennerstam H, Schmidt S, Näsholm T. Amino acid transporter mutants of Arabidopsis provides evidence that a non-mycorrhizal plant acquires organic nitrogen from agricultural soil. Plant Cell Environ 2017; 40:413-423. [PMID: 27943312 DOI: 10.1111/pce.12881] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Revised: 11/16/2016] [Accepted: 11/21/2016] [Indexed: 05/03/2023]
Abstract
Although organic nitrogen (N) compounds are ubiquitous in soil solutions, their potential role in plant N nutrition has been questioned. We performed a range of experiments on Arabidopsis thaliana genetically modified to enhance or reduce root uptake of amino acids. Plants lacking expression of the Lysine Histidine Transporter 1 (LHT1) displayed significantly lower contents of 13 C and 15 N label and of U-13 C5 ,15 N2 L-glutamine, as determined by liquid chromatography-mass spectrometry when growing in pots and supplied with dually labelled L-glutamine compared to wild type plants and LHT1-overexpressing plants. Slopes of regressions between accumulation of 13 C-labelled carbon and 15 N-labelled N were higher for LHT1-overexpressing plants than wild type plants, while plants lacking expression of LHT1 did not display a significant regression between the two isotopes. Uptake of labelled organic N from soil tallied with that of labelled ammonium for wild type plants and LHT1-overexpressing plants but was significantly lower for plants lacking expression of LHT1. When grown on agricultural soil plants lacking expression of LHT1 had the lowest, and plants overexpressing LHT1 the highest C/N ratios and natural δ15 N abundance suggesting their dependence on different N pools. Our data show that LHT1 expression is crucial for plant uptake of organic N from soil.
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Affiliation(s)
- Ulrika Ganeteg
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Iftikhar Ahmad
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Sandra Jämtgård
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Camila Aguetoni-Cambui
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Erich Inselsbacher
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
- University of Vienna, Department of Geography and Regional Research, Vienna, AT-1090, Austria
| | - Henrik Svennerstam
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
| | - Susanne Schmidt
- School of Agriculture and Food Sciences, The University of Queensland, QLD, 4072, Brisbane, Australia
| | - Torgny Näsholm
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, SE-901 83, Umeå, Sweden
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27
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Mathieu C, Macêdo JP, Hürlimann D, Wirdnam C, Haindrich AC, Suter Grotemeyer M, González-Salgado A, Schmidt RS, Inbar E, Mäser P, Bütikofer P, Zilberstein D, Rentsch D. Arginine and Lysine Transporters Are Essential for Trypanosoma brucei. PLoS One 2017; 12:e0168775. [PMID: 28045943 PMCID: PMC5207785 DOI: 10.1371/journal.pone.0168775] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 12/06/2016] [Indexed: 12/14/2022] Open
Abstract
For Trypanosoma brucei arginine and lysine are essential amino acids and therefore have to be imported from the host. Heterologous expression in Saccharomyces cerevisiae mutants identified cationic amino acid transporters among members of the T. brucei AAAP (amino acid/auxin permease) family. TbAAT5-3 showed high affinity arginine uptake (Km 3.6 ± 0.4 μM) and high selectivity for L-arginine. L-arginine transport was reduced by a 10-times excess of L-arginine, homo-arginine, canavanine or arginine-β-naphthylamide, while lysine was inhibitory only at 100-times excess, and histidine or ornithine did not reduce arginine uptake rates significantly. TbAAT16-1 is a high affinity (Km 4.3 ± 0.5 μM) and highly selective L-lysine transporter and of the compounds tested, only L-lysine and thialysine were competing for L-lysine uptake. TbAAT5-3 and TbAAT16-1 are expressed in both procyclic and bloodstream form T. brucei and cMyc-tagged proteins indicate localization at the plasma membrane. RNAi-mediated down-regulation of TbAAT5 and TbAAT16 in bloodstream form trypanosomes resulted in growth arrest, demonstrating that TbAAT5-mediated arginine and TbAAT16-mediated lysine transport are essential for T. brucei. Growth of induced RNAi lines could partially be rescued by supplementing a surplus of arginine or lysine, respectively, while addition of both amino acids was less efficient. Single and double RNAi lines indicate that additional low affinity uptake systems for arginine and lysine are present in T. brucei.
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Affiliation(s)
| | - Juan P. Macêdo
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Daniel Hürlimann
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | - Corina Wirdnam
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
| | | | | | | | - Remo S. Schmidt
- Swiss Tropical and Public Health Institute and University of Basel, Basel, Switzerland
| | - Ehud Inbar
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Pascal Mäser
- Swiss Tropical and Public Health Institute and University of Basel, Basel, Switzerland
| | - Peter Bütikofer
- Institute of Biochemistry and Molecular Medicine, University of Bern, Bern, Switzerland
| | - Dan Zilberstein
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
| | - Doris Rentsch
- Institute of Plant Sciences, University of Bern, Bern, Switzerland
- * E-mail:
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28
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EauClaire SF, Zhang J, Rivera CG, Huang LL. Combinatorial metabolic pathway assembly in the yeast genome with RNA-guided Cas9. J Ind Microbiol Biotechnol 2016; 43:1001-15. [PMID: 27138038 DOI: 10.1007/s10295-016-1776-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Accepted: 04/11/2016] [Indexed: 12/13/2022]
Abstract
The yeast Saccharomyces cerevisiae is an important industrial platform for the production of grain and cellulosic ethanol, isobutanol, butanediol, isoprenoids, and other chemicals. The construction of a successful production strain usually involves multiple gene knockouts and chromosomal integration of expression cassettes to redirect the metabolic fluxes for the conversion of sugars and other feed stocks into the desired product. RNA-guided Cas9 based genome editing has been demonstrated in many prokaryotic and eukaryotic hosts including S. cerevisiae, in which it has been additionally exploited as a tool for metabolic engineering. To extend the utilization of RNA-guided Cas9 as a metabolic pathway building tool, we demonstrated the direct assembly and chromosomal integration of up to 17 overlapping DNA fragments encoding the beta-carotene biosynthetic pathway. Furthermore, we generated a combinatorial strain library for the beta-carotene biosynthetic pathway, directly integrated into the yeast genome to create a diverse library of strains. This enabled the screening of combinatorial libraries in stable chromosomally integrated strains for rapid improvements of product titers. This combinatorial approach for pathway assembly will significantly accelerate the current speed of metabolic engineering for S. cerevisiae as an industrial platform, and increase the number of strains that can be simultaneously evaluated for enzyme screening, expression optimization and protein engineering to achieve the titer, rate and yield necessary for the commercialization of new industrial fermentation products.
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Affiliation(s)
| | - Jianzhong Zhang
- Industrial Biosciences, E. I. Du Pont Company, Wilmington, DE, USA
| | | | - Lixuan L Huang
- Industrial Biosciences, E. I. Du Pont Company, Wilmington, DE, USA.
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Laranjeira-Silva MF, Zampieri RA, Muxel SM, Floeter-Winter LM, Markus RP. Melatonin attenuates Leishmania (L.) amazonensis infection by modulating arginine metabolism. J Pineal Res 2015; 59:478-87. [PMID: 26383232 DOI: 10.1111/jpi.12279] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/11/2015] [Indexed: 01/08/2023]
Abstract
Acute inflammatory responses induced by bacteria or fungi block nocturnal melatonin synthesis by rodent pineal glands. Here, we show Leishmania infection does not impair daily melatonin rhythm in hamsters. Remarkably, the attenuated parasite burden and lesion progression in hamsters infected at nighttime was impaired by blockage of melatonin receptors with luzindole, whereas melatonin treatment during the light phase attenuated Leishmania infection. In vitro studies corroborated in vivo observations. Melatonin treatment reduced macrophage expression of Cat-2b, Cat1, and ArgI, genes involved in arginine uptake and polyamine synthesis. Indeed, melatonin reduced macrophage arginine uptake by 40%. Putrescine supplementation reverted the attenuation of infectivity by melatonin indicating that its effect was due to the arrest of parasite replication. This study shows that the Leishmania/host interaction varies in a circadian manner according to nocturnal melatonin pineal synthesis. Our results provide new data regarding Leishmania infectiveness and show new approaches for applying agonists of melatonin receptors in Leishmaniasis therapy.
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Affiliation(s)
| | | | - Sandra M Muxel
- Institute of Biosciences, University of São Paulo, São Paulo, Brazil
| | | | - Regina P Markus
- Institute of Biosciences, University of São Paulo, São Paulo, Brazil
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Kurko J, Vähä-Mäkilä M, Tringham M, Tanner L, Paavanen-Huhtala S, Saarinen M, Näntö-Salonen K, Simell O, Niinikoski H, Mykkänen J. Dysfunction in macrophage toll-like receptor signaling caused by an inborn error of cationic amino acid transport. Mol Immunol 2015. [PMID: 26210182 DOI: 10.1016/j.molimm.2015.07.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Amino acids, especially arginine, are vital for the well-being and activity of immune cells, and disruption of amino acid balance may weaken immunity and predispose to infectious and autoimmune diseases. We present here a model of an inborn aminoaciduria, lysinuric protein intolerance (LPI), in which a single mutation in y(+)LAT1 cationic amino acid transporter gene SLC7A7 leads to a multisystem disease characterized by immunological complications, life-threatening pulmonary alveolar proteinosis and nephropathy. Macrophages are suggested to play a central role in LPI in the development of these severe secondary symptoms. We thus studied the effect of the Finnish y(+)LAT1 mutation on monocyte-derived macrophages where toll-like receptors (TLRs) act as the key molecules in innate immune response against external pathogens. The function of LPI patient and control macrophage TLR signaling was examined by stimulating the TLR2/1, TLR4 and TLR9 pathways with their associated pathogen-associated molecular patterns. Downregulation in expression of TLR9, IRF7, IRF3 and IFNB1 and in secretion of IFN-α was detected, suggesting an impaired response to TLR9 stimulation. In addition, secretion of TNF-α, IL-12 and IL-1RA by TLR2/1 stimulation and IL-12 and IL-1RA by TLR4 stimulation was increased in the LPI patients. LPI macrophages secreted significantly less nitric oxide than control macrophages, whereas plasma concentrations of inflammatory chemokines CXCL8, CXCL9 and CXCL10 were elevated in the LPI patients. In conclusion, our results strengthen the relevance of macrophages in the pathogenesis of LPI and, furthermore, suggest that cationic amino acid transport plays an important role in the regulation of innate immune responses.
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Affiliation(s)
- Johanna Kurko
- Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland.
| | - Mari Vähä-Mäkilä
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland.
| | - Maaria Tringham
- Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland.
| | - Laura Tanner
- Department of Medical Biochemistry and Genetics, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland; Department of Clinical Genetics, Turku University Hospital, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland.
| | - Sari Paavanen-Huhtala
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland.
| | - Maiju Saarinen
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland; Department of Public Health, University of Turku, Lemminkäisenkatu 1, 20014 Turku, Finland.
| | - Kirsti Näntö-Salonen
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland.
| | - Olli Simell
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland.
| | - Harri Niinikoski
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland.
| | - Juha Mykkänen
- Department of Pediatrics, Turku University Hospital and University of Turku, Kiinamyllynkatu 4-8, PL 52, 20521 Turku, Finland; Research Centre of Applied and Preventive Cardiovascular Medicine, University of Turku, Kiinamyllynkatu 10, 20520 Turku, Finland.
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Monné M, Miniero DV, Daddabbo L, Palmieri L, Porcelli V, Palmieri F. Mitochondrial transporters for ornithine and related amino acids: a review. Amino Acids 2015; 47:1763-77. [PMID: 26002808 DOI: 10.1007/s00726-015-1990-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Accepted: 04/15/2015] [Indexed: 12/18/2022]
Abstract
Among the members of the mitochondrial carrier family, there are transporters that catalyze the translocation of ornithine and related substrates, such as arginine, homoarginine, lysine, histidine, and citrulline, across the inner mitochondrial membrane. The mitochondrial carriers ORC1, ORC2, and SLC25A29 from Homo sapiens, BAC1 and BAC2 from Arabidopsis thaliana, and Ort1p from Saccharomyces cerevisiae have been biochemically characterized by transport assays in liposomes. All of them transport ornithine and amino acids with side chains terminating at least with one amine. There are, however, marked differences in their substrate specificities including their affinity for ornithine (KM values in the mM to μM range). These differences are most likely reflected by minor differences in the substrate binding sites of these carriers. The physiological role of the above-mentioned mitochondrial carriers is to link several metabolic pathways that take place partly in the cytosol and partly in the mitochondrial matrix and to provide basic amino acids for mitochondrial translation. In the liver, human ORC1 catalyzes the citrulline/ornithine exchange across the mitochondrial inner membrane, which is required for the urea cycle. Human ORC1, ORC2, and SLC25A29 are likely to be involved in the biosynthesis and transport of arginine, which can be used as a precursor for the synthesis of NO, agmatine, polyamines, creatine, glutamine, glutamate, and proline, as well as in the degradation of basic amino acids. BAC1 and BAC2 are implicated in some processes similar to those of their human counterparts and in nitrogen and amino acid metabolism linked to stress conditions and the development of plants. Ort1p is involved in the biosynthesis of arginine and polyamines in yeast.
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Affiliation(s)
- Magnus Monné
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Via E. Orabona 4, 70125, Bari, Italy
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Marobbio CMT, Punzi G, Pierri CL, Palmieri L, Calvello R, Panaro MA, Palmieri F. Pathogenic potential of SLC25A15 mutations assessed by transport assays and complementation of Saccharomyces cerevisiae ORT1 null mutant. Mol Genet Metab 2015; 115:27-32. [PMID: 25818551 DOI: 10.1016/j.ymgme.2015.03.003] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/30/2015] [Revised: 03/09/2015] [Accepted: 03/09/2015] [Indexed: 01/25/2023]
Abstract
HHH syndrome is an autosomal recessive urea cycle disorder caused by alterations in the SLC25A15 gene encoding the mitochondrial ornithine carrier 1, which catalyzes the transport of cytosolic ornithine into the mitochondria in exchange for intramitochondrial citrulline. In this study the functional effects of several SLC25A15 missense mutations p.G27R, p.M37R, p.N74A, p.F188L, p.F188Y, p.S200K, p.R275Q and p.R275K have been tested by transport assays in reconstituted liposomes and complementation of Saccharomyces cerevisiae ORT1 null mutant in arginine-less synthetic complete medium. The HHH syndrome-causing mutations p.G27R, p.M37R, p.F188L and p.R275Q had impaired transport and did not complement ORT1∆ cells (except p.M37R slightly after 5 days in solid medium). The experimentally produced mutations p.N74A, p.S200K and p.R275K exhibited normal or considerable transport activity and complemented ORT1∆ cells after 3 days (p.N74A, p.S200K) or 5 days (p.R275K) incubation. Furthermore, the experimentally produced p.F188Y mutation displayed a substantial transport activity but did not complement the ORT1∆ cells in both liquid and solid media. In view of the disagreement in the results obtained between the two methods, it is recommended that the method of complementing the S. cerevisiae ORT1 knockout strain is used complimentary with the measurement of the catalytic activity, in order to distinguish HHH syndrome-causing mutations from isomorphisms.
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Affiliation(s)
- Carlo M T Marobbio
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy
| | - Giuseppe Punzi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy
| | - Ciro L Pierri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy
| | - Luigi Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy
| | - Rosa Calvello
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy
| | - Maria A Panaro
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy
| | - Ferdinando Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, via Orabona 4, 70125 Bari, Italy.
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Grossi M, Rippe C, Sathanoori R, Swärd K, Forte A, Erlinge D, Persson L, Hellstrand P, Nilsson BO. Vascular smooth muscle cell proliferation depends on caveolin-1-regulated polyamine uptake. Biosci Rep 2014; 34:e00153. [PMID: 25301005 PMCID: PMC4240025 DOI: 10.1042/bsr20140140] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Accepted: 10/09/2014] [Indexed: 12/11/2022] Open
Abstract
Much evidence highlights the importance of polyamines for VSMC (vascular smooth muscle cell) proliferation and migration. Cav-1 (caveolin-1) was recently reported to regulate polyamine uptake in intestinal epithelial cells. The aim of the present study was to assess the importance of Cav-1 for VSMC polyamine uptake and its impact on cell proliferation and migration. Cav-1 KO (knockout) mouse aortic cells showed increased polyamine uptake and elevated proliferation and migration compared with WT (wild-type) cells. Both Cav-1 KO and WT cells expressed the smooth muscle differentiation markers SM22 and calponin. Cell-cycle phase distribution analysis revealed a higher proportion of Cav-1 KO than WT cells in the S phase. Cav-1 KO cells were hyper-proliferative in the presence but not in the absence of extracellular polyamines, and, moreover, supplementation with exogenous polyamines promoted proliferation in Cav-1 KO but not in WT cells. Expression of the solute carrier transporters Slc7a1 and Slc43a1 was higher in Cav-1 KO than in WT cells. ODC (ornithine decarboxylase) protein and mRNA expression as well as ODC activity were similar in Cav-1 KO and WT cells showing unaltered synthesis of polyamines in Cav-1 KO cells. Cav-1 was reduced in migrating cells in vitro and in carotid lesions in vivo. Our data show that Cav-1 negatively regulates VSMC polyamine uptake and that the proliferative advantage of Cav-1 KO cells is critically dependent on polyamine uptake. We provide proof-of-principle for targeting Cav-1-regulated polyamine uptake as a strategy to fight unwanted VSMC proliferation as observed in restenosis.
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Key Words
- caveolin-1
- cell cycle
- ornithine decarboxylase
- polyamine transporter
- polyamine
- vascular smooth muscle cell
- asmc, aortic smooth muscle cell
- cav-1, caveolin-1
- cea, carotid endarterectomy
- dfmo, difluoromethylornithine
- dmem, dulbecco’s modified eagle’s medium
- hbss, hanks balanced salt solution
- [3h]put, [3h]putrescine
- hrp, horseradish peroxidise
- [3h]spd, [3h]spermidine
- hsp90, heat-shock protein 90
- ko, knockout
- odc, ornithine decarboxylase
- pi, propidium iodide
- qrt-pcr, quantitative real-time pcr
- vsmc, vascular smooth muscle cell
- wt, wild-type
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MESH Headings
- Amino Acid Transport Systems, Basic/genetics
- Amino Acid Transport Systems, Basic/metabolism
- Animals
- Blotting, Western
- Calcium-Binding Proteins/metabolism
- Carotid Arteries/metabolism
- Carotid Arteries/surgery
- Caveolin 1/genetics
- Caveolin 1/metabolism
- Cell Movement
- Cell Proliferation
- Cells, Cultured
- DNA/biosynthesis
- Gene Expression
- Immunohistochemistry
- Mice, Inbred C57BL
- Mice, Knockout
- Microfilament Proteins/metabolism
- Muscle Proteins/metabolism
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Ornithine Decarboxylase/genetics
- Ornithine Decarboxylase/metabolism
- Polyamines/metabolism
- Polyamines/pharmacokinetics
- Polyamines/pharmacology
- Rats, Wistar
- Reverse Transcriptase Polymerase Chain Reaction
- Calponins
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Affiliation(s)
- Mario Grossi
- *Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Catarina Rippe
- *Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Ramasri Sathanoori
- †Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden
| | - Karl Swärd
- *Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Amalia Forte
- ‡Department of Experimental Medicine, Second University of Naples, Naples, Italy
| | - David Erlinge
- †Department of Cardiology, Clinical Sciences, Lund University, Lund, Sweden
| | - Lo Persson
- *Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Per Hellstrand
- *Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Bengt-Olof Nilsson
- *Department of Experimental Medical Science, Lund University, Lund, Sweden
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Hou ML, Chang LW, Lin CH, Lin LC, Tsai TH. Comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats and microarray analysis of drug-metabolizing genes. J Ethnopharmacol 2014; 155:1291-1299. [PMID: 25046826 DOI: 10.1016/j.jep.2014.07.022] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Revised: 06/26/2014] [Accepted: 07/10/2014] [Indexed: 06/03/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Rhein is a pharmacological active component found in Rheum palmatum L. that is the major herb of the San-Huang-Xie-Xin-Tang (SHXXT), a medicinal herbal product used as a remedy for constipation. Here we have investigated the comparative pharmacokinetics of rhein in normal and constipated rats. Microarray analysis was used to explore whether drug-metabolizing genes will be altered after SHXXT treatment. MATERIALS AND METHODS The comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats was studied by liquid chromatography with electrospray ionization tandem mass spectrometry (LC-MS/MS). Gene expression profiling in drug-metabolizing genes after SHXXT treatment was investigated by microarray analysis and real-time polymerase chain reaction (RT-PCR). RESULTS A validated LC-MS/MS method was applied to investigate the comparative pharmacokinetics of rhein in normal and loperamide-induced constipated rats. The pharmacokinetic results demonstrate that the loperamide-induced constipation reduced the absorption of rhein. Cmax significantly reduced by 2.5-fold, the AUC decreased by 27.8%; however, the elimination half-life (t1/2) was prolonged by 1.6-fold. Tmax and mean residence time (MRT) were significantly prolonged by 2.8-fold, and 1.7-fold, respectively. The volume of distribution (Vss) increased by 2.2-fold. The data of microarray analysis on gene expression indicate that five drug-metabolizing genes, including Cyp7a1, Cyp2c6, Ces2e, Atp1b1, and Slc7a2 were significantly altered by the SHXXT (0.5 g/kg) treatment. CONCLUSION The loperamide-induced constipation reduced the absorption of rhein. Since among the 25,338 genes analyzed, there were five genes significantly altered by SHXXT treatment. Thus, information on minor drug-metabolizing genes altered by SHXXT treatment indicates that SHXXT is relatively safe for clinical application.
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Affiliation(s)
- Mei-Ling Hou
- Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Li-Wen Chang
- Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan
| | - Chi-Hung Lin
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan
| | - Lie-Chwen Lin
- National Research Institute of Chinese Medicine, Taipei, Taiwan
| | - Tung-Hu Tsai
- Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan; Graduate Institute of Acupuncture Science, China Medical University, Taichung, Taiwan; Department of Education and Research, Taipei City Hospital, Taipei, Taiwan.
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Yang H, Krebs M, Stierhof YD, Ludewig U. Characterization of the putative amino acid transporter genes AtCAT2, 3 &4: the tonoplast localized AtCAT2 regulates soluble leaf amino acids. J Plant Physiol 2014; 171:594-601. [PMID: 24709150 DOI: 10.1016/j.jplph.2013.11.012] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/08/2013] [Revised: 11/26/2013] [Accepted: 11/26/2013] [Indexed: 05/03/2023]
Abstract
The plant vacuole constitutes a large transient storage compartment for nutrients, proteins and metabolites, and is a major cellular sink for toxic waste compounds. Amino acids can cross the vacuolar membrane via specific transport proteins, which are molecularly not well characterized. Two members of a small subfamily of the cationic amino acid transporters, AtCAT2 and AtCAT4, were primarily localized at the tonoplast when tagged with GFP. The closely related AtCAT3, by contrast, was detected in the endoplasmic reticulum membrane. The exchange of a di-acidic motif at the carboxy-tail affected their sub-cellular localization, with larger effects visible in transiently transformed protoplasts compared to stably expressing plant lines. The genes have broad, partially overlapping tissue expression, with CAT2 dominating in most tissues. Loss-of-function mutants of individual CATs showed no visible phenotype under various conditions, but the overall tissue concentration of amino acids was increased in soil-grown cat2 mutants. The data suggest that CAT2 is a critical target of leaf amino acid concentrations and manipulation of this tonoplast transporter can significantly alter total tissue amino acid concentrations.
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Affiliation(s)
- Huaiyu Yang
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr. 20, 70593 Stuttgart, Germany; Center for Molecular Biology of Plants (ZMBP), Microscopy Unit, University of Tübingen, Auf der Morgenstelle 5, 72076 Tübingen, Germany
| | - Melanie Krebs
- Center for Molecular Biology of Plants (ZMBP), Microscopy Unit, University of Tübingen, Auf der Morgenstelle 5, 72076 Tübingen, Germany
| | - York-Dieter Stierhof
- Center for Molecular Biology of Plants (ZMBP), Microscopy Unit, University of Tübingen, Auf der Morgenstelle 5, 72076 Tübingen, Germany
| | - Uwe Ludewig
- Institute of Crop Science, Nutritional Crop Physiology, University of Hohenheim, Fruwirthstr. 20, 70593 Stuttgart, Germany; Center for Molecular Biology of Plants (ZMBP), Microscopy Unit, University of Tübingen, Auf der Morgenstelle 5, 72076 Tübingen, Germany.
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Ersoy Tunalı N, Marobbio CMT, Tiryakioğlu NO, Punzi G, Saygılı SK, Onal H, Palmieri F. A novel mutation in the SLC25A15 gene in a Turkish patient with HHH syndrome: functional analysis of the mutant protein. Mol Genet Metab 2014; 112:25-9. [PMID: 24721342 PMCID: PMC4015418 DOI: 10.1016/j.ymgme.2014.03.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 03/12/2014] [Accepted: 03/12/2014] [Indexed: 01/13/2023]
Abstract
The hyperornithinemia-hyperammonemia-homocitrullinuria syndrome is a rare autosomal recessive disorder caused by the functional deficiency of the mitochondrial ornithine transporter 1 (ORC1). ORC1 is encoded by the SLC25A15 gene and catalyzes the transport of cytosolic ornithine into mitochondria in exchange for citrulline. Although the age of onset and the severity of the symptoms vary widely, the disease usually manifests in early infancy. The typical clinical features include protein intolerance, lethargy, episodic confusion, cerebellar ataxia, seizures and mental retardation. In this study, we identified a novel p.Ala15Val (c.44C>T) mutation by genomic DNA sequencing in a Turkish child presenting severe tantrum, confusion, gait disturbances and loss of speech abilities in addition to hyperornithinemia, hyperammonemia and homocitrullinuria. One hundred Turkish control chromosomes did not possess this variant. The functional effect of the novel mutation was assessed by both complementation of the yeast ORT1 null mutant and transport assays. Our study demonstrates that the A15V mutation dramatically interferes with the transport properties of ORC1 since it was shown to inhibit ornithine transport nearly completely.
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Affiliation(s)
- Nagehan Ersoy Tunalı
- Department of Molecular Biology and Genetics, Haliç University, Istanbul, Turkey.
| | - Carlo M T Marobbio
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - N Ozan Tiryakioğlu
- Department of Molecular Biology and Genetics, Haliç University, Istanbul, Turkey
| | - Giuseppe Punzi
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
| | - Seha K Saygılı
- Istanbul Medical Faculty, Department of Pediatrics, Istanbul University, Istanbul, Turkey
| | - Hasan Onal
- Department of Pediatric Metabolism and Nutrition, Kanuni Sultan Süleyman Research and Training Hospital, Istanbul, Turkey
| | - Ferdinando Palmieri
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy.
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Abstract
Lysine is an essential amino acid for human nutrition, which is generally low in cereal diets. Its biosynthesis via the aspartate-pathway and catabolism is controlled by complex feedback mechanisms. Recently, aspartate-derived amino acids were found to be elevated during pathogen infection in Arabidopsis and a lysine catabolite, pipecolic acid, was identified as critical regulator of systemic acquired resistance. Pipecolic acid is mobile in plants, functions as an intensifier of defense responses and mediates systemic acquired resistance establishment via signal amplification. The altered pathogen defense in several mutants with altered homeostasis of aspartate-derived amino acids, such as lysine, had already provided a genetic link with amino acid homeostasis. Furthermore, the modification of amino acid transport and distribution within tissues not only affected the plant growth performance, but also the plant-pathogen interaction. The ectopic overexpression of a gene encoding a high affinity importer with preference to basic amino acids, such as lysine, cationic amino acid transporter1 (CAT1), improved the disease resistance to a hemibiotrophic bacterial pathogen in Arabidopsis via a constitutively activated salicylic acid pathway. The importance of Asp-derived amino acid homeostasis for plant systemic acquired resistance and on overall plant growth performance may be relevant to resistance and nutritional quality breeding. Whether nitrogen fertilization has an impact on crop pest control management via amino acid homeostasis is briefly discussed.
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Elashry A, Okumoto S, Siddique S, Koch W, Kreil DP, Bohlmann H. The AAP gene family for amino acid permeases contributes to development of the cyst nematode Heterodera schachtii in roots of Arabidopsis. Plant Physiol Biochem 2013; 70:379-86. [PMID: 23831821 PMCID: PMC3737465 DOI: 10.1016/j.plaphy.2013.05.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 05/09/2013] [Indexed: 05/02/2023]
Abstract
The beet cyst nematode Heterodera schachtii is able to infect Arabidopsis plants and induce feeding sites in the root. These syncytia are the only source of nutrients for the nematodes throughout their life and are a nutrient sink for the host plant. We have studied here the role of amino acid transporters for nematode development. Arabidopsis contains a large number of different amino acid transporters in several gene families but those of the AAP family were found to be especially expressed in syncytia. Arabidopsis contains 8 AAP genes and they were all strongly expressed in syncytia with the exception of AAP5 and AAP7, which were slightly downregulated. We used promoter::GUS lines and in situ RT-PCR to confirm the expression of several AAP genes and LHT1, a lysine- and histidine-specific amino acid transporter, in syncytia. The strong expression of AAP genes in syncytia indicated that these transporters are important for the transport of amino acids into syncytia and we used T-DNA mutants for several AAP genes to test for their influence on nematode development. We found that mutants of AAP1, AAP2, and AAP8 significantly reduced the number of female nematodes developing on these plants. Our study showed that amino acid transport into syncytia is important for the development of the nematodes.
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Affiliation(s)
- Abdelnaser Elashry
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna. UFT Tulln, Konrad Lorenz Str. 24, 3430 Tulln, Austria
| | - Sakiko Okumoto
- Department of Plant Pathology, Physiology, and Weed Science, 549 Latham Hall (0390), Virginia Tech, Blacksburg, VA 24061, USA
| | - Shahid Siddique
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna. UFT Tulln, Konrad Lorenz Str. 24, 3430 Tulln, Austria
| | - Wolfgang Koch
- KWS SAAT AG, Grimsehlstrasse 31, 37574 Einbeck, Germany
| | - David P. Kreil
- Chair of Bioinformatics, Department of Biotechnology, University of Natural Resources and Life Sciences, Vienna, Austria
- School of Life Sciences, University of Warwick, UK
| | - Holger Bohlmann
- Division of Plant Protection, Department of Crop Sciences, University of Natural Resources and Life Sciences, Vienna. UFT Tulln, Konrad Lorenz Str. 24, 3430 Tulln, Austria
- Corresponding author. Tel.: +43 1 47654 3360; fax: +43 1 47654 3359.
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Czyz O, Bitew T, Cuesta-Marbán A, McMaster CR, Mollinedo F, Zaremberg V. Alteration of plasma membrane organization by an anticancer lysophosphatidylcholine analogue induces intracellular acidification and internalization of plasma membrane transporters in yeast. J Biol Chem 2013; 288:8419-8432. [PMID: 23344949 PMCID: PMC3605658 DOI: 10.1074/jbc.m112.425744] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 01/15/2013] [Indexed: 11/06/2022] Open
Abstract
The lysophosphatidylcholine analogue edelfosine is a potent antitumor lipid that targets cellular membranes. The underlying mechanisms leading to cell death remain controversial, although two cellular membranes have emerged as primary targets of edelfosine, the plasma membrane (PM) and the endoplasmic reticulum. In an effort to identify conditions that enhance or prevent the cytotoxic effect of edelfosine, we have conducted genome-wide surveys of edelfosine sensitivity and resistance in Saccharomyces cerevisiae presented in this work and the accompanying paper (Cuesta-Marbán, Á., Botet, J., Czyz, O., Cacharro, L. M., Gajate, C., Hornillos, V., Delgado, J., Zhang, H., Amat-Guerri, F., Acuña, A. U., McMaster, C. R., Revuelta, J. L., Zaremberg, V., and Mollinedo, F. (January 23, 2013) J. Biol. Chem. 288,), respectively. Our results point to maintenance of pH homeostasis as a major player in modulating susceptibility to edelfosine with the PM proton pump Pma1p playing a main role. We demonstrate that edelfosine alters PM organization and induces intracellular acidification. Significantly, we show that edelfosine selectively reduces lateral segregation of PM proteins like Pma1p and nutrient H(+)-symporters inducing their ubiquitination and internalization. The biology associated to the mode of action of edelfosine we have unveiled includes selective modification of lipid raft integrity altering pH homeostasis, which in turn regulates cell growth.
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Affiliation(s)
- Ola Czyz
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Teshager Bitew
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada
| | - Alvaro Cuesta-Marbán
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas-Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain
| | - Christopher R McMaster
- Department of Pharmacology, Atlantic Research Centre, Dalhousie University, Halifax, Nova Scotia B3H 4H7, Canada
| | - Faustino Mollinedo
- Instituto de Biología Molecular y Celular del Cáncer, Centro de Investigación del Cáncer, Consejo Superior de Investigaciones Científicas-Universidad de Salamanca, Campus Miguel de Unamuno, E-37007 Salamanca, Spain.
| | - Vanina Zaremberg
- Department of Biological Sciences, University of Calgary, Calgary, Alberta T2N 1N4, Canada.
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McKenna KC, Beatty KM, Scherder RC, Li F, Liu H, Chen AF, Ghosh A, Stuehr DJ. Ascorbate in aqueous humor augments nitric oxide production by macrophages. J Immunol 2013; 190:556-64. [PMID: 23241881 PMCID: PMC3538947 DOI: 10.4049/jimmunol.1201754] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Immunosuppressive molecules within the aqueous humor (AqH) are thought to preserve ocular immune privilege by inhibiting proinflammatory NO production by macrophages (MΦs). Consistent with previous observations, we observed that although MΦs stimulated in the presence of AqH expressed NO synthase 2 (NOS2) protein, nitrite concentrations in culture supernatants, an indirect measure of NO production, did not increase. Interestingly, NOS2 enzymatic activity, as measured by the conversion of L-arginine (L-Arg) into L-citrulline, was augmented in lysates of MΦs stimulated in the presence of AqH. These data suggested that intracellular L-Arg may have been limited by AqH. However, we observed increased mRNA expression of the L-Arg transporter, cationic amino acid transporter 2B, and increased L-Arg uptake in MΦs stimulated in the presence of AqH. Arginases were expressed by stimulated Ms, but competition for L-Arg with NOS2 was excluded. Expression of GTP cyclohydrolase, which produces tetrahydrobiopterin (H(4)B), an essential cofactor for NOS2 homodimerization, increased after M stimulation in the presence or absence of AqH and NOS2 homodimers formed. Taken together, these data provided no evidence for inhibited NOS2 enzymatic activity by AqH, suggesting that a factor within AqH may have interfered with the measurement of nitrite. Indeed, we observed that nitrite standards were not measurable in the presence of AqH, and this effect was due to ascorbate in AqH. Controlling for interference by ascorbate revealed that AqH augmented NO production in MΦs via ascorbate, which limited degradation of H(4)B. Therefore, AqH may augment NO production in macrophages by stabilizing H(4)B and increasing intracellular L-Arg.
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Affiliation(s)
- Kyle C McKenna
- Department of Ophthalmology, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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Marella HH, Nielsen E, Schachtman DP, Taylor CG. The amino acid permeases AAP3 and AAP6 are involved in root-knot nematode parasitism of Arabidopsis. Mol Plant Microbe Interact 2013; 26:44-54. [PMID: 23194341 DOI: 10.1094/mpmi-05-12-0123-fi] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
The root-knot nematode, Meloidogyne incognita, is an obligate parasite which depends entirely on the host plant for its nutrition. Root-knot nematodes induce the formation of a highly specialized feeding site consisting of several giant cells surrounded by a network of vascular tissues. Nutrients, including amino acids and sugars, are transferred apoplastically from the vascular tissues to the feeding site. Using Arabidopsis thaliana lacking the vascular-expressed amino acid permeases (AAP) AAP3 or AAP6, we demonstrate that disruption of amino acid transport can affect nematode parasitism. Nematode infestation levels are significantly reduced on the aap3 and aap6 mutants. AAP3 and AAP6 act distinctly in the transport of amino acids to the feeding site, as demonstrated by differences in their carrying capacity profiles. Furthermore, analyses of promoter: β-glucuronidase lines show different expression patterns for AAP3 and AAP6 in infected roots. In the aap3-3 mutant, part of the decrease in infestation is connected to a defect in early infection, where juveniles enter but then leave the root. Both aap3-3 and aap6-1 produce fewer females and produce more adult male nematodes. Additionally, detrimental effects are observed in the nematodes harvested from aap3-3 and aap6-1 mutants, including decreased egg hatching and infectivity and lower levels of lipid reserves. The transport of amino acids by AAP3 and AAP6 is important for nematode infection and success of the progeny.
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Abstract
Defective catabolite export from lysosomes results in lysosomal storage diseases in humans. Mutations in the cystine transporter gene CTNS cause cystinosis, but other lysosomal amino acid transporters are poorly characterized at the molecular level. Here, we identified the Caenorhabditis elegans lysosomal lysine/arginine transporter LAAT-1. Loss of laat-1 caused accumulation of lysine and arginine in enlarged, degradation-defective lysosomes. In mutants of ctns-1 (C. elegans homolog of CTNS), LAAT-1 was required to reduce lysosomal cystine levels and suppress lysosome enlargement by cysteamine, a drug that alleviates cystinosis by converting cystine to a lysine analog. LAAT-1 also maintained availability of cytosolic lysine/arginine during embryogenesis. Thus, LAAT-1 is the lysosomal lysine/arginine transporter, which suggests a molecular explanation for how cysteamine alleviates a lysosomal storage disease.
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Affiliation(s)
- Bin Liu
- Graduate Program in Chinese Academy of Medical Sciences and Peking Union Medical College, China
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing, 102206, China
| | - Hongwei Du
- State Key Laboratory of Molecular and Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
- Graduate School, Chinese Academy of Sciences, Beijing, 100039, China
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing, 102206, China
| | - Rachael Rutkowski
- Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Anton Gartner
- Wellcome Trust Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee, DD1 5EH, United Kingdom
| | - Xiaochen Wang
- National Institute of Biological Sciences, No. 7 Science Park Road, Zhongguancun Life Science Park, Beijing, 102206, China
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Wang JF, Chou KC. Insights into the mutation-induced HHH syndrome from modeling human mitochondrial ornithine transporter-1. PLoS One 2012; 7:e31048. [PMID: 22292090 PMCID: PMC3266937 DOI: 10.1371/journal.pone.0031048] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 12/30/2011] [Indexed: 11/25/2022] Open
Abstract
Human mitochondrial ornithine transporter-1 is reported in coupling with the hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome, which is a rare autosomal recessive disorder. For in-depth understanding of the molecular mechanism of the disease, it is crucially important to acquire the 3D structure of human mitochondrial ornithine transporter-1. Since no such structure is available in the current protein structure database, we have developed it via computational approaches based on the recent NMR structure of human mitochondrial uncoupling protein (Berardi MJ, Chou JJ, et al. Nature 2011, 476:109–113). Subsequently, we docked the ligand L-ornithine into the computational structure to search for the favorable binding mode. It was observed that the binding interaction for the most favorable binding mode is featured by six remarkable hydrogen bonds between the receptor and ligand, and that the most favorable binding mode shared the same ligand-binding site with most of the homologous mitochondrial carriers from different organisms, implying that the ligand-binding sites are quite conservative in the mitochondrial carriers family although their sequences similarity is very low with 20% or so. Moreover, according to our structural analysis, the relationship between the disease-causing mutations of human mitochondrial ornithine transporter-1 and the HHH syndrome can be classified into the following three categories: (i) the mutation occurs in the pseudo-repeat regions so as to change the region of the protein closer to the mitochondrial matrix; (ii) the mutation is directly affecting the substrate binding pocket so as to reduce the substrate binding affinity; (iii) the mutation is located in the structural region closer to the intermembrane space that can significantly break the salt bridge networks of the protein. These findings may provide useful insights for in-depth understanding of the molecular mechanism of the HHH syndrome and developing effective drugs against the disease.
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Affiliation(s)
- Jing-Fang Wang
- Key Laboratory of Systems Biomedicine, Ministry of Education, Shanghai Jiao Tong University, Shanghai, China.
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Svennerstam H, Jämtgård S, Ahmad I, Huss-Danell K, Näsholm T, Ganeteg U. Transporters in Arabidopsis roots mediating uptake of amino acids at naturally occurring concentrations. New Phytol 2011; 191:459-467. [PMID: 21453345 DOI: 10.1111/j.1469-8137.2011.03699.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Recent studies of Arabidopsis have identified several transporters as being important for amino acid uptake. We used Arabidopsis plants with altered expression of lysine histidine transporter 1 (LHT1), amino acid permease 1 (AAP1) and amino acid permease 5 (AAP5) with the aim of disentangling the roles of each transporter in the uptake of different amino acids at naturally occurring concentrations (2-50 μM). LHT1 mutants displayed reduced uptake rates of L-Gln, L-Ala, L-Glu and L-Asp but not of L-Arg or L-Lys, while AAP5 mutants were affected in the uptake of L-Arg and L-Lys only. Double mutants (lht1aap5) exhibited reduced uptake of all tested amino acids. In the concentration range tested, AAP1 mutants did not display altered uptake rates for any of the studied amino acids. Expression analysis of amino acid transporter genes with important root functions revealed no major differences in the individual mutants other than for genes targeted for mutation. We conclude that LHT1 and AAP5, but not AAP1, are crucial for amino acid uptake at concentrations typically found in soils. LHT1 and AAP5 displayed complementary affinity spectra, and no redundancy with respect to gene expression was found between the two transporters, suggesting these two transporters have separate roles in amino acid uptake.
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Affiliation(s)
- Henrik Svennerstam
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
| | - Sandra Jämtgård
- Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
| | - Iftikhar Ahmad
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
| | - Kerstin Huss-Danell
- Department of Agricultural Research for Northern Sweden, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
| | - Torgny Näsholm
- Department of Forest Ecology and Management, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
| | - Ulrika Ganeteg
- Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences (SLU), SE-901 83 Umeå, Sweden
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Grijota-Martínez C, Díez D, Morreale de Escobar G, Bernal J, Morte B. Lack of action of exogenously administered T3 on the fetal rat brain despite expression of the monocarboxylate transporter 8. Endocrinology 2011; 152:1713-21. [PMID: 21303950 DOI: 10.1210/en.2010-1014] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mutations of the monocarboxylate transporter 8 gene (MCT8, SLC16A2) cause the Allan-Herndon-Dudley syndrome, an X-linked syndrome of severe intellectual deficit and neurological impairment. Mct8 transports thyroid hormones (T4 and T3), and the Allan-Herndon-Dudley syndrome is likely caused by lack of T3 transport to neurons during critical periods of fetal brain development. To evaluate the role of Mct8 in thyroid hormone action in the fetal brain we administered T4 or T3 to thyroidectomized pregnant dams treated with methyl-mercapto-imidazol to produce maternal and fetal hypothyroidism. Gene expression was then measured in the fetal cerebral cortex. T4 increased Camk4, Sema3c, and Slc7a3 expression, but T3 was without effect. To investigate the cause for the lack of T3 action we analyzed the expression of organic anion transport polypeptide (Oatp14, Slco1c1), a T4 transporter, and Mct8 (Slc16a2), a T4 and T3 transporter, by confocal microscopy. Both proteins were present in the brain capillaries forming the blood-brain barrier and in the epithelial cells of the choroid plexus forming the blood-cerebrospinal fluid barrier. It is concluded that T4 from the maternal compartment influences gene expression in the fetal cerebral cortex, possibly after transport via organic anion transporter polypeptide and/or Mct8, and conversion to T3 in the astrocytes. On the other hand, T3 does not reach the target neurons despite the presence of Mct8. The data indicate that T4, through local deiodination, provides most T3 in the fetal rat brain. The role of Mct8 as a T3 transporter in the fetal rat brain is therefore uncertain.
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Liu G, Ji Y, Bhuiyan NH, Pilot G, Selvaraj G, Zou J, Wei Y. Amino acid homeostasis modulates salicylic acid-associated redox status and defense responses in Arabidopsis. Plant Cell 2010; 22:3845-63. [PMID: 21097712 PMCID: PMC3015111 DOI: 10.1105/tpc.110.079392] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2010] [Revised: 09/13/2010] [Accepted: 10/28/2010] [Indexed: 05/17/2023]
Abstract
The tight association between nitrogen status and pathogenesis has been broadly documented in plant-pathogen interactions. However, the interface between primary metabolism and disease responses remains largely unclear. Here, we show that knockout of a single amino acid transporter, LYSINE HISTIDINE TRANSPORTER1 (LHT1), is sufficient for Arabidopsis thaliana plants to confer a broad spectrum of disease resistance in a salicylic acid-dependent manner. We found that redox fine-tuning in photosynthetic cells was causally linked to the lht1 mutant-associated phenotypes. Furthermore, the enhanced resistance in lht1 could be attributed to a specific deficiency of its main physiological substrate, Gln, and not to a general nitrogen deficiency. Thus, by enabling nitrogen metabolism to moderate the cellular redox status, a plant primary metabolite, Gln, plays a crucial role in plant disease resistance.
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Affiliation(s)
- Guosheng Liu
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Yuanyuan Ji
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Nazmul H. Bhuiyan
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
| | - Guillaume Pilot
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305
| | - Gopalan Selvaraj
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Jitao Zou
- Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, Saskatchewan S7N 0W9, Canada
| | - Yangdou Wei
- Department of Biology, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E2, Canada
- Address correspondence to
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Toka I, Planchais S, Cabassa C, Justin AM, De Vos D, Richard L, Savouré A, Carol P. Mutations in the hyperosmotic stress-responsive mitochondrial BASIC AMINO ACID CARRIER2 enhance proline accumulation in Arabidopsis. Plant Physiol 2010; 152:1851-62. [PMID: 20172963 PMCID: PMC2850005 DOI: 10.1104/pp.109.152371] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Accepted: 02/12/2010] [Indexed: 05/21/2023]
Abstract
Mitochondrial carrier family proteins are diverse in their substrate specificity, organellar location, and gene expression. In Arabidopsis (Arabidopsis thaliana), 58 genes encode these six-transmembrane-domain proteins. We investigated the biological role of the basic amino acid carrier Basic Amino Acid Carrier2 (BAC2) from Arabidopsis that is structurally and functionally similar to ARG11, a yeast ornithine and arginine carrier, and to Arabidopsis BAC1. By studying the expression of BAC2 and the consequences of its mutation in Arabidopsis, we showed that BAC2 is a genuine mitochondrial protein and that Arabidopsis requires expression of the BAC2 gene in order to use arginine. The BAC2 gene is induced by hyperosmotic stress (with either 0.2 m NaCl or 0.4 m mannitol) and dark-induced senescence. The BAC2 promoter contains numerous stress-related cis-regulatory elements, and the transcriptional activity of BAC2:beta-glucuronidase is up-regulated by stress and senescence. Under hyperosmotic stress, bac2 mutants express the P5CS1 proline biosynthetic gene more strongly than the wild type, and this correlates with a greater accumulation of Pro. Our data suggest that BAC2 is a hyperosmotic stress-inducible transporter of basic amino acids that contributes to proline accumulation in response to hyperosmotic stress in Arabidopsis.
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Affiliation(s)
| | | | | | | | | | | | | | - Pierre Carol
- Laboratoire de Physiologie Cellulaire et Moléculaire des Plantes, Université Pierre et Marie Curie (Paris 6), UR5 EAC7180 CNRS, Case 156, 75005 Paris, France
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Anand BS, Katragadda S, Nashed YE, Mitra AK. Amino acid prodrugs of acyclovir as possible antiviral agents against ocular HSV-1 infections: Interactions with the neutral and cationic amino acid transporter on the corneal epithelium. Curr Eye Res 2009; 29:153-66. [PMID: 15512962 DOI: 10.1080/02713680490504614] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
PURPOSE The aim of this study was to explore the feasibility of improvement of ocular bioavailability of the antiviral agent acyclovir by designing amino acid prodrugs targeted to the amino acid transporters on the rabbit cornea. MATERIALS AND METHODS Transcorneal flux of two water-soluble amino acid ester prodrugs of acyclovir (ACV), gamma-glutamate-ACV (EACV) and L-tyrosine-ACV (YACV), was studied across freshly excised rabbit cornea. Chemical and enzymatic hydrolysis studies of the two prodrugs were also conducted. RESULTS EACV inhibited the uptake of [(3)H]L-Arg in rabbit primary corneal epithelial cells (rPCECs). The compound also exhibited longer half-life (t(1/2)) in cornea in comparison to YACV. Transcorneal flux of EACV was observed to be concentration-, energy-, and sodium-dependent and independent of pH within the range studied. EACV transport was inhibited by neutral and cationic amino acids, L-ornithine (specific for cationic amino acids), and BCH (2-aminobicyclo-[2,2,1]-heptane-2-carboxylic-acid) (specific inhibitor for L-type system and B(0,+) system). On the other hand, YACV was not recognized by this amino acid transporter as it failed to inhibit the uptake of [(3)H]Arg, and also its transport across cornea was not inhibited by arginine. YACV and EACV exhibited excellent antiviral activity against HSV-1 and 2 and Varicella-Zoster Virus (VZV) in comparison to ACV. CONCLUSIONS Analyses of the inhibition pattern of EACV transport suggests the involvement of a single transport system; namely, B(0,+). Design of amino acid prodrugs seems to be an attractive strategy to enhance the solubility of the otherwise poorly aqueous soluble compounds and also to afford a targeted and possibly enhanced delivery of the active drug.
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Affiliation(s)
- Banmeet S Anand
- Division of Pharmaceutical Sciences, School of Pharmacy, University of Missouri-Kansas City, 5005 Rockhill Road, Kansas City, MO 64110, USA
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Abstract
In vivo transcription of the Escherichia coli argO gene, which encodes an arginine (Arg) exporter, requires the LysR-family regulator protein ArgP (previously called IciA) and is induced in the presence of Arg or its naturally occurring antimetabolite analog canavanine. Lysine (Lys) addition, on the other hand, phenocopies an argP mutation to result in the shutoff of argO expression. We now report that the ArgP dimer by itself is able to bind the argO promoter-operator region to form a binary complex, but that the formation of a ternary complex with RNA polymerase is greatly stimulated only in presence of a coeffector. Both Arg and Lys were proficient as coeffectors for ArgP-mediated recruitment of RNA polymerase to, and open complex formation at, the argO promoter, although only Arg (but not Lys) was competent to activate transcription. The two coeffectors competed for binding to ArgP, and the ternary complex that had been assembled on the argO template in the presence of Lys could be chased into a transcriptionally active state upon Arg addition. Our results support a novel mechanism of argO regulation in which Lys-bound ArgP reversibly restrains RNA polymerase at the promoter, at a step (following open complex formation) that precedes, and is common to, both abortive and productive transcription. This represents, therefore, the first example of an environmental signal regulating the final step of promoter clearance by RNA polymerase in bacterial transcription. We propose that, in E. coli cells, the ternary complex remains assembled and poised at the argO promoter at all times to respond, positively or negatively, to instantaneous changes in the ratio of intracellular Arg to Lys concentrations.
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Affiliation(s)
- Rakesh S. Laishram
- Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500076, India
| | - Jayaraman Gowrishankar
- Laboratory of Bacterial Genetics, Centre for DNA Fingerprinting and Diagnostics, Hyderabad 500076, India
- Corresponding author.E-MAIL ; FAX 91-40-27155610
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