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Xia T, Chen K, Zhou H, Chen T, Lin W, Xiao G, Fang R. Regulation of Arginine Metabolism and Ethanol Tolerance in Saccharomyces cerevisiae by BTN2. Food Sci Nutr 2025; 13:e70244. [PMID: 40321608 PMCID: PMC12045926 DOI: 10.1002/fsn3.70244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2024] [Revised: 03/28/2025] [Accepted: 04/24/2025] [Indexed: 05/08/2025] Open
Abstract
Ethyl carbamate (EC), primarily formed by the reaction between urea and ethanol, is a natural carcinogen prevalent in fermented alcoholic beverages. Urea is an arginine metabolite produced by Saccharomyces cerevisiae. Previous studies have shown that BTN2 influences arginine metabolism. In this study, we compared the effects of BTN2-modified strains on key metabolites, enzymes, and transcriptional gene expressions in the arginine metabolic pathway, and assessed cell growth and oxidative damage under different ethanol stresses. It revealed that the knockout of BTN2 inhibited arginine intake and promoted urea reduction. RT-qPCR results demonstrated that BTN2 regulate arginine transportation, catabolism, and urea degradation by modulating the expression of GAP1, CAN1, CAR1, and DUR1,2. Moreover, the results showed that BTN2 enhanced ethanol tolerance and alleviated cellular damage. These findings provide a promising method for reducing arginine uptake by Saccharomyces cerevisiae and consequently urea accumulation in wine.
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Affiliation(s)
- Ting Xia
- School of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhouChina
| | - Keiwei Chen
- Youxian Shop (Zhejiang) Food Co. Ltd.HuzhouChina
| | - Huqi Zhou
- School of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhouChina
| | - Tangchao Chen
- School of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhouChina
| | - Wenjing Lin
- School of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhouChina
| | - Gongnian Xiao
- School of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhouChina
| | - Ruosi Fang
- School of Biological and Chemical EngineeringZhejiang University of Science and TechnologyHangzhouChina
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2
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Matilla MA, Gavira JA, Monteagudo-Cascales E, Zhulin IB, Krell T. Structural and functional diversity of sensor domains in bacterial transmembrane receptors. Trends Microbiol 2025:S0966-842X(25)00076-9. [PMID: 40121131 DOI: 10.1016/j.tim.2025.02.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2024] [Revised: 02/25/2025] [Accepted: 02/26/2025] [Indexed: 03/25/2025]
Abstract
The ability of bacteria to adapt to changing environmental conditions largely depends on transmembrane receptors that sense signal molecules and generate responses such as chemotaxis, changes in gene expression, or alterations in second-messenger levels. Although these receptors differ significantly in function, they share a common mode of activation that involves signal molecule interaction with sensor domains. A major challenge in microbiology lies in the limited knowledge of ligands that stimulate receptors. Here, we review recent advances in this field, including the occurrence of multi-modular sensor domains, the identification of co-component signal transduction systems, evidence for sensor domain evolution from transporters, and the use of binding pocket sequence motifs to identify sensor domain ligands.
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Affiliation(s)
- Miguel A Matilla
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada, 18008, Spain
| | - José A Gavira
- Laboratory of Crystallographic Studies, CSIC-UGR, Avenida de las Palmeras 4, Armilla, 18100, Spain
| | - Elizabet Monteagudo-Cascales
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada, 18008, Spain
| | - Igor B Zhulin
- Department of Microbiology and Translational Data Analytics Institute, The Ohio State University, Columbus, OH 43210, USA
| | - Tino Krell
- Department of Biotechnology and Environmental Protection, Estación Experimental del Zaidín, Consejo Superior de Investigaciones Científicas, Prof. Albareda 1, Granada, 18008, Spain.
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3
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Partipilo M, Slotboom DJ. The S-component fold: a link between bacterial transporters and receptors. Commun Biol 2024; 7:610. [PMID: 38773269 PMCID: PMC11109136 DOI: 10.1038/s42003-024-06295-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2024] [Accepted: 05/06/2024] [Indexed: 05/23/2024] Open
Abstract
The processes of nutrient uptake and signal sensing are crucial for microbial survival and adaptation. Membrane-embedded proteins involved in these functions (transporters and receptors) are commonly regarded as unrelated in terms of sequence, structure, mechanism of action and evolutionary history. Here, we analyze the protein structural universe using recently developed artificial intelligence-based structure prediction tools, and find an unexpected link between prominent groups of microbial transporters and receptors. The so-called S-components of Energy-Coupling Factor (ECF) transporters, and the membrane domains of sensor histidine kinases of the 5TMR cluster share a structural fold. The discovery of their relatedness manifests a widespread case of prokaryotic "transceptors" (related proteins with transport or receptor function), showcases how artificial intelligence-based structure predictions reveal unchartered evolutionary connections between proteins, and provides new avenues for engineering transport and signaling functions in bacteria.
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Affiliation(s)
- Michele Partipilo
- Department of Biochemistry, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands
| | - Dirk Jan Slotboom
- Department of Biochemistry, Groningen Institute of Biomolecular Sciences & Biotechnology, University of Groningen, Nijenborgh 4, 9747 AG, Groningen, The Netherlands.
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4
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Nishimura A. Regulations and functions of proline utilization in yeast Saccharomyces cerevisiae. Biosci Biotechnol Biochem 2024; 88:131-137. [PMID: 37994668 DOI: 10.1093/bbb/zbad165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 11/18/2023] [Indexed: 11/24/2023]
Abstract
The quality of alcoholic beverages strongly depends on the metabolic characteristics of the yeast cells being used. To control the aroma and the taste of alcoholic beverages, as well as the production of ethanol in them, it is thus crucial to select yeast cells with the proper characteristics. Grape must contain a high concentration of proline, an amino acid that can potentially be a useful nitrogen source. However, Saccharomyces cerevisiae cannot utilize proline during the wine-making process, resulting in the elevated levels of proline in wine and consequent negative effects on wine quality. In this article, I review and discuss recent discoveries about the inhibitory mechanisms and roles of proline utilization in yeast. The information can help in developing novel yeast strains that can improve fermentation and enhance the quality and production efficiency of wine.
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Affiliation(s)
- Akira Nishimura
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara, Japan
- Institute for Research Initiatives, Nara Institute of Science and Technology, Ikoma, Nara, Japan
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5
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Tanahashi R, Nishimura A, Morita F, Nakazawa H, Taniguchi A, Ichikawa K, Nakagami K, Boundy-Mills K, Takagi H. The arginine transporter Can1 acts as a transceptor for regulation of proline utilization in the yeast Saccharomyces cerevisiae. Yeast 2023; 40:333-348. [PMID: 36573467 DOI: 10.1002/yea.3836] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 11/29/2022] [Accepted: 12/23/2022] [Indexed: 12/28/2022] Open
Abstract
Proline is the most abundant amino acid in wine and beer, because the yeast Saccharomyces cerevisiae hardly assimilates proline during fermentation processes. Our previous studies showed that arginine induces endocytosis of the proline transporter Put4, resulting in inhibition of proline utilization. We here report a possible role of arginine sensing in the inhibition of proline utilization. We first found that two basic amino acids, ornithine, and lysine, inhibit proline utilization by inducing Put4 endocytosis in a manner similar to arginine, but citrulline does not. Our genetic screening revealed that the arginine transporter Can1 is involved in the inhibition of proline utilization by arginine. Intriguingly, the arginine uptake activity of Can1 was not required for the arginine-dependent inhibition of proline utilization, suggesting that Can1 has a function beyond its commonly known function of transporting arginine. More importantly, our biochemical analyses revealed that Can1 activates signaling cascades of protein kinase A in response to extracellular arginine. Hence, we proposed that Can1 regulates proline utilization by functioning as a transceptor possessing the activity of both a transporter and receptor of arginine.
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Affiliation(s)
- Ryoya Tanahashi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
- Division for Research Strategy, Institute for Research Initiatives, Nara Institute of Science and Technology, Ikoma, Japan
- Department of Food Science and Technology, University of California Davis, Davis, California, USA
| | - Akira Nishimura
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Fumika Morita
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Hayate Nakazawa
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Atsuki Taniguchi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Kazuki Ichikawa
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Kazuki Nakagami
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
| | - Kyria Boundy-Mills
- Department of Food Science and Technology, University of California Davis, Davis, California, USA
| | - Hiroshi Takagi
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Japan
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6
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Venugopalan V, Rehders M, Weber J, Rodermund L, Al-Hashimi A, Bargmann T, Golchert J, Reinecke V, Homuth G, Völker U, Verrey F, Kirstein J, Heuer H, Schweizer U, Braun D, Wirth EK, Brix K. Lack of L-type amino acid transporter 2 in murine thyroid tissue induces autophagy. J Mol Endocrinol 2023; 70:JME-22-0060. [PMID: 36129170 DOI: 10.1530/jme-22-0060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 09/21/2022] [Indexed: 01/19/2023]
Abstract
Proteolytic cleavage of thyroglobulin (Tg) for thyroid hormone (TH) liberation is followed by TH release from thyroid follicles into the circulation, enabled by TH transporters. The existence of a functional link between Tg-processing cathepsin proteases and TH transporters has been shown to be independent of the hypothalamus-pituitary-thyroid axis. Thus, lack of cathepsin K, combined with genetic defects in the TH transporters Mct8 and Mct10, that is the Ctsk-/-/Mct8-/y/Mct10-/- genotype, results in persistent Tg proteolysis due to autophagy induction. Because amino acid transport by L-type amino acid transporter 2 (Lat2) has been described to regulate autophagy, we asked whether Lat2 availability is affected in Ctsk-/-/Mct8-/y/Mct10-/- thyroid glands. Our data revealed that while mRNA amounts and subcellular localization of Lat2 remained unaltered in thyroid tissue of Ctsk-/-/Mct8-/y/Mct10-/- mice in comparison to WT controls, the Lat2 protein amounts were significantly reduced. These data suggest a direct link between Lat2 function and autophagy induction in Ctsk-/-/Mct8-/y/Mct10-/- mice. Indeed, thyroid tissue of Lat2-/- mice showed enhanced endo-lysosomal cathepsin activities, increased autophagosome formation, and enhanced autophagic flux. Collectively, these results suggest a mechanistic link between insufficient Lat2 protein function and autophagy induction in the thyroid gland of male mice.
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Affiliation(s)
| | - Maren Rehders
- School of Science, Jacobs University Bremen, Bremen, Germany
| | - Jonas Weber
- School of Science, Jacobs University Bremen, Bremen, Germany
| | - Lisa Rodermund
- School of Science, Jacobs University Bremen, Bremen, Germany
| | - Alaa Al-Hashimi
- School of Science, Jacobs University Bremen, Bremen, Germany
| | - Tonia Bargmann
- School of Science, Jacobs University Bremen, Bremen, Germany
| | - Janine Golchert
- Department of Functional Genomics, University Medicine Greifswald, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Vivien Reinecke
- Department of Functional Genomics, University Medicine Greifswald, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Georg Homuth
- Department of Functional Genomics, University Medicine Greifswald, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Uwe Völker
- Department of Functional Genomics, University Medicine Greifswald, Interfaculty Institute for Genetics and Functional Genomics, Greifswald, Germany
| | - Francois Verrey
- Physiologisches Institut, Universität Zürich, Zürich, Switzerland
| | - Janine Kirstein
- Fachbereich 2 Biologie/Chemie, Faculty of Cell Biology, Universität Bremen, Bremen, Germany
| | - Heike Heuer
- Department of Endocrinology, Diabetes and Metabolism, Universitätsklinikum Essen, Essen, Germany
| | - Ulrich Schweizer
- Institut für Biochemie und Molekularbiologie, Medizinische Fakultät, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Doreen Braun
- Institut für Biochemie und Molekularbiologie, Medizinische Fakultät, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
| | - Eva K Wirth
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
- Department of Endocrinology and Metabolism, Berlin Institute of Health, Berlin, Germany
- DZHK (German Centre for Cardiovascular Research), partner site Berlin, Germany
| | - Klaudia Brix
- School of Science, Jacobs University Bremen, Bremen, Germany
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7
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Schrevens S, Durandau E, Tran VDT, Sanglard D. Using in vivo transcriptomics and RNA enrichment to identify genes involved in virulence of Candida glabrata. Virulence 2022; 13:1285-1303. [PMID: 35795910 PMCID: PMC9348041 DOI: 10.1080/21505594.2022.2095716] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Candida species are the most commonly isolated opportunistic fungal pathogens in humans. Candida albicans causes most of the diagnosed infections, closely followed by Candida glabrata. C. albicans is well studied, and many genes have been shown to be important for infection and colonization of the host. It is however less clear how C. glabrata infects the host. With the help of fungal RNA enrichment, we here investigated for the first time the transcriptomic profile of C. glabrata during urinary tract infection (UTI) in mice. In the UTI model, bladders and kidneys are major target organs and therefore fungal transcriptomes were addressed in these organs. Our results showed that, next to adhesins and proteases, nitrogen metabolism and regulation play a vital role during C. glabrata UTI. Genes involved in nitrogen metabolism were upregulated and among them we show that DUR1,2 (urea amidolyase) and GAP1 (amino acid permease) were important for virulence. Furthermore, we confirmed the importance of the glyoxylate cycle in the host and identified MLS1 (malate synthase) as an important gene necessary for C. glabrata virulence. In conclusion, our study shows with the support of in vivo transcriptomics how C. glabrata adapts to host conditions.
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Affiliation(s)
- Sanne Schrevens
- Institute of Microbiology, University of Lausanne and University Hospital, CH-1011 Lausanne, Switzerland
| | - Eric Durandau
- Institute of Microbiology, University of Lausanne and University Hospital, CH-1011 Lausanne, Switzerland
| | - Van Du T Tran
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, CH-1015 Lausanne, Switzerland
| | - Dominique Sanglard
- Institute of Microbiology, University of Lausanne and University Hospital, CH-1011 Lausanne, Switzerland
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8
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Ishii R, Fukui A, Sakihama Y, Kitsukawa S, Futami A, Mochizuki T, Nagano M, Toshima J, Abe F. Substrate-induced differential degradation and partitioning of the two tryptophan permeases Tat1 and Tat2 into eisosomes in Saccharomyces cerevisiae. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2022; 1864:183858. [PMID: 35031272 DOI: 10.1016/j.bbamem.2021.183858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 12/22/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Tryptophan is a relatively rare amino acid whose influx is strictly controlled to meet cellular demands. The yeast Saccharomyces cerevisiae has two tryptophan permeases, namely Tat1 (low-affinity type) and Tat2 (high-affinity type). These permeases are differentially regulated through ubiquitination based on inducible conditions and dependence on arrestin-related trafficking adaptors, although the physiological significance of their degradation remain unclear. Here, we demonstrated that Tat2 was rapidly degraded in an Rsp5-Bul1-dependent manner upon the addition of tryptophan, phenylalanine, or tyrosine, whereas Tat1 was unaffected. The expression of the ubiquitination-deficient variant Tat25K>R led to a reduction in cell yield at 4 μg/mL tryptophan, suggesting the occurrence of an uncontrolled, excessive consumption of tryptophan at low tryptophan concentrations. Eisosomes are membrane furrows that are thought to be storage compartments for some nutrient permeases. Tryptophan addition caused rapid Tat2 dissociation from eisosomes, whereas Tat1 distribution was unaffected. The 5 K > R mutation had no marked effect on Tat2 dissociation, suggesting that dissociation is independent of ubiquitination. Interestingly, the D74R mutation, which was created within the N-terminal acidic patch, stabilized Tat2 while reducing the degree of partitioning into eisosomes. Moreover, the hyperactive I285V mutation in Tat2, which increases Vmax/Km for tryptophan import by 2-fold, reduced the degree of segregation into eisosomes. Our findings illustrate the coordinated activity of Tat1 and Tat2 in the regulation of tryptophan transport at various tryptophan concentrations and suggest the positive role of substrates in inducing a conformational transition in Tat2, resulting in its dissociation from eisosomes and subsequent ubiquitination-dependent degradation.
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Affiliation(s)
- Ryoga Ishii
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Ayu Fukui
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Yuri Sakihama
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Shoko Kitsukawa
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Ayami Futami
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan
| | - Takahiro Mochizuki
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan; Division of Medical Biochemistry, Faculty of Medicine, Tohoku Medical and Pharmaceutical University, 1-15-1, Fukumuro, Miyagino-ku, Sendai, Miyagi 983-8536, Japan
| | - Makoto Nagano
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Jiro Toshima
- Department of Biological Science and Technology, Tokyo University of Science, 6-3-1 Niijyuku, Katsushika-ku, Tokyo 125-8585, Japan
| | - Fumiyoshi Abe
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara 252-5258, Japan.
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9
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Lei HT, Mu X, Hattne J, Gonen T. A conformational change in the N terminus of SLC38A9 signals mTORC1 activation. Structure 2021; 29:426-432.e8. [PMID: 33296665 PMCID: PMC9994763 DOI: 10.1016/j.str.2020.11.014] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2020] [Revised: 10/20/2020] [Accepted: 11/16/2020] [Indexed: 11/28/2022]
Abstract
mTORC1 is a central hub that integrates environmental cues, such as cellular stresses and nutrient availability to modulate metabolism and cellular responses. Recently, SLC38A9, a lysosomal amino acid transporter, emerged as a sensor for luminal arginine and as an activator of mTORC1. The amino acid-mediated activation of mTORC1 is regulated by the N-terminal domain of SLC38A9. Here, we determined the crystal structure of zebrafish SLC38A9 (drSLC38A9) and found the N-terminal fragment inserted deep within the transporter, bound in the substrate-binding pocket where normally arginine would bind. This represents a significant conformational change of the N-terminal domain (N-plug) when compared with our recent arginine-bound structure of drSLC38A9. We propose a ball-and-chain model for mTORC1 activation, where N-plug insertion and Rag GTPase binding with SLC38A9 is regulated by luminal arginine levels. This work provides important insights into nutrient sensing by SLC38A9 to activate the mTORC1 pathways in response to dietary amino acids.
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Affiliation(s)
- Hsiang-Ting Lei
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Xuelang Mu
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Departments of Biological Chemistry and Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Johan Hattne
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Departments of Biological Chemistry and Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tamir Gonen
- Howard Hughes Medical Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA; Departments of Biological Chemistry and Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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10
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Dai J, Xia H, Yang C, Chen X. Sensing, Uptake and Catabolism of L-Phenylalanine During 2-Phenylethanol Biosynthesis via the Ehrlich Pathway in Saccharomyces cerevisiae. Front Microbiol 2021; 12:601963. [PMID: 33717002 PMCID: PMC7947893 DOI: 10.3389/fmicb.2021.601963] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 01/29/2021] [Indexed: 01/15/2023] Open
Abstract
2-Phenylethanol (2-PE) is an important flavouring ingredient with a persistent rose-like odour, and it has been widely utilized in food, perfume, beverages, and medicine. Due to the potential existence of toxic byproducts in 2-PE resulting from chemical synthesis, the demand for “natural” 2-PE through biotransformation is increasing. L-Phenylalanine (L-Phe) is used as the precursor for the biosynthesis of 2-PE through the Ehrlich pathway by Saccharomyces cerevisiae. The regulation of L-Phe metabolism in S. cerevisiae is complicated and elaborate. We reviewed current progress on the signal transduction pathways of L-Phe sensing, uptake of extracellular L-Phe and 2-PE synthesis from L-Phe through the Ehrlich pathway. Moreover, the anticipated bottlenecks and future research directions for S. cerevisiae biosynthesis of 2-PE are discussed.
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Affiliation(s)
- Jun Dai
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China.,ABI Group, College of Marine Science and Technology, Zhejiang Ocean University, Zhoushan, China.,State Key Laboratory of Biocatalysis and Enzyme Engineering, School of Life Sciences, Hubei University, Wuhan, China
| | - Huili Xia
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Chunlei Yang
- Tobacco Research Institute of Hubei Province, Wuhan, China
| | - Xiong Chen
- Key Laboratory of Fermentation Engineering (Ministry of Education), National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Hubei Provincial Cooperative Innovation Center of Industrial Fermentation, College of Bioengineering, Hubei University of Technology, Wuhan, China
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11
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Zhang Z, Cottignie I, Van Zeebroeck G, Thevelein JM. Nutrient transceptors physically interact with the yeast S6/protein kinase B homolog, Sch9, a TOR kinase target. Biochem J 2021; 478:357-375. [PMID: 33394033 PMCID: PMC7850899 DOI: 10.1042/bcj20200722] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 12/04/2020] [Accepted: 01/04/2021] [Indexed: 12/18/2022]
Abstract
Multiple starvation-induced, high-affinity nutrient transporters in yeast function as receptors for activation of the protein kinase A (PKA) pathway upon re-addition of their substrate. We now show that these transceptors may play more extended roles in nutrient regulation. The Gap1 amino acid, Mep2 ammonium, Pho84 phosphate and Sul1 sulfate transceptors physically interact in vitro and in vivo with the PKA-related Sch9 protein kinase, the yeast homolog of mammalian S6 protein kinase and protein kinase B. Sch9 is a phosphorylation target of TOR and well known to affect nutrient-controlled cellular processes, such as growth rate. Mapping with peptide microarrays suggests specific interaction domains in Gap1 for Sch9 binding. Mutagenesis of the major domain affects the upstart of growth upon the addition of L-citrulline to nitrogen-starved cells to different extents but apparently does not affect in vitro binding. It also does not correlate with the drop in L-citrulline uptake capacity or transceptor activation of the PKA target trehalase by the Gap1 mutant forms. Our results reveal a nutrient transceptor-Sch9-TOR axis in which Sch9 accessibility for phosphorylation by TOR may be affected by nutrient transceptor-Sch9 interaction under conditions of nutrient starvation or other environmental challenges.
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Affiliation(s)
- Zhiqiang Zhang
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Ines Cottignie
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Johan M. Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
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12
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Maghiaoui A, Gojon A, Bach L. NRT1.1-centered nitrate signaling in plants. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:6226-6237. [PMID: 32870279 DOI: 10.1093/jxb/eraa361] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 08/14/2020] [Indexed: 05/21/2023]
Abstract
Plants need efficient nitrate (NO3-) sensing systems and sophisticated signaling pathways to develop a wide range of adaptive responses to external fluctuations of NO3- supply. In Arabidopsis thaliana, numerous molecular regulators have been identified to participate in signaling pathways that respond specifically to NO3-. In contrast, only a single NO3- sensing system has been described to date, relying on the NRT1.1 (NPF6.3/CHL1) NO3- transceptor. NRT1.1 governs a wide range of responses to NO3-, from fast reprogramming of genome expression (the primary nitrate response) to longer-term developmental changes (effects on lateral root development). NRT1.1 appears to be at the center of a complex network of signaling pathways, involving numerous molecular players acting downstream and/or upstream of it. Interestingly, some of these regulators are involved in crosstalk with the signaling pathways of other nutrients, such as inorganic phosphate or potassium. Although NRT1.1-mediated NO3- sensing and signaling has mostly been documented in Arabidopsis, recent evidence indicates that similar mechanisms involving NRT1.1 orthologues are operative in rice. This review aims to delineate how the NRT1.1 sensing system and the downstream/upstream transduction cascades are integrated to control both the expression of NO3--responsive genes and the induced plasticity of root development.
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Affiliation(s)
- Amel Maghiaoui
- Biochimie et Physiologie Moléculaire des Plantes (BPMP), UMR 5004 CNRS/INRAE/SupAgro-M/UM2, Institut de Biologie Intégrative des Plantes, Place Viala, France
| | - Alain Gojon
- Biochimie et Physiologie Moléculaire des Plantes (BPMP), UMR 5004 CNRS/INRAE/SupAgro-M/UM2, Institut de Biologie Intégrative des Plantes, Place Viala, France
| | - Liên Bach
- Biochimie et Physiologie Moléculaire des Plantes (BPMP), UMR 5004 CNRS/INRAE/SupAgro-M/UM2, Institut de Biologie Intégrative des Plantes, Place Viala, France
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13
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Abstract
We review the mechanisms responsible for amino acid homeostasis in Saccharomyces cerevisiae and other fungi. Amino acid homeostasis is essential for cell growth and survival. Hence, the de novo synthesis reactions, metabolic conversions, and transport of amino acids are tightly regulated. Regulation varies from nitrogen pool sensing to control by individual amino acids and takes place at the gene (transcription), protein (posttranslational modification and allostery), and vesicle (trafficking and endocytosis) levels. The pools of amino acids are controlled via import, export, and compartmentalization. In yeast, the majority of the amino acid transporters belong to the APC (amino acid-polyamine-organocation) superfamily, and the proteins couple the uphill transport of amino acids to the electrochemical proton gradient. Although high-resolution structures of yeast amino acid transporters are not available, homology models have been successfully exploited to determine and engineer the catalytic and regulatory functions of the proteins. This has led to a further understanding of the underlying mechanisms of amino acid sensing and subsequent downregulation of transport. Advances in optical microscopy have revealed a new level of regulation of yeast amino acid transporters, which involves membrane domain partitioning. The significance and the interrelationships of the latest discoveries on amino acid homeostasis are put in context.
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14
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Ring A, Martins A, Ljungdahl PO. Ssy1 functions at the plasma membrane as a receptor of extracellular amino acids independent of plasma membrane-endoplasmic reticulum junctions. Traffic 2019; 20:775-784. [PMID: 31336002 DOI: 10.1111/tra.12681] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 01/23/2023]
Abstract
Evidence from multiple laboratories has implicated Ssy1, a nontransporting amino acid permease, as the receptor component of the yeast plasma membrane (PM)-localized SPS (Ssy1-Ptr3-Ssy5)-sensor. Upon binding external amino acids, Ssy1 is thought to initiate signaling events leading to the induction of amino acid permease gene expression. In striking contrast, Kralt et al (2015) (Traffic 16:135-147) have questioned the role of Ssy1 in amino acid sensing and reported that Ssy1 is a component of the endoplasmic reticulum (ER), where it reportedly participates in the formation of ER-PM junctions. Here, we have re-examined the intracellular location of Ssy1 and tested the role of ER-PM junctions in SPS sensor signaling. We show that the C-terminal of Ssy1 carries a functional ER-export motif required for proper localization of Ssy1 to the PM. Furthermore, ER-PM junctions are dispensable for PM-localization and function of Ssy1; Ssy1 localizes to the PM in a Δtether strain lacking ER-PM junctions (ist2Δ scs2Δ scs22Δ tcb1Δ tcb2Δ tcb3Δ), and this strain retains the ability to initiate signals induced by extracellular amino acids. The data demonstrate that Ssy1 functions as the primary amino acid receptor and that it carries out this function at the PM.
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Affiliation(s)
- Andreas Ring
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - António Martins
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Per O Ljungdahl
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
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15
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Role of Amino Acid Metabolism in the Virulence of Human Pathogenic Fungi. CURRENT CLINICAL MICROBIOLOGY REPORTS 2019. [DOI: 10.1007/s40588-019-00124-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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16
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Abstract
Cell nutrition, detoxification, signalling, homeostasis and response to drugs, processes related to cell growth, differentiation and survival are all mediated by plasma membrane (PM) proteins called transporters. Despite their distinct fine structures, mechanism of function, energetic requirements, kinetics and substrate specificities, all transporters are characterized by a main hydrophobic body embedded in the PM as a series of tightly packed, often intertwined, α-helices that traverse the lipid bilayer in a zigzag mode, connected with intracellular or extracellular loops and hydrophilic N- and C-termini. Whereas longstanding genetic, biochemical and biophysical evidence suggests that specific transmembrane segments, and also their connecting loops, are responsible for substrate recognition and transport dynamics, emerging evidence also reveals the functional importance of transporter N- and C-termini, in respect to transport catalysis, substrate specificity, subcellular expression, stability and signalling. This review highlights selected prototypic examples of transporters in which their termini play important roles in their functioning.
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Affiliation(s)
- Emmanuel Mikros
- Faculty of Pharmacy, National and Kapodistrian University of Athens, Panepistimioupolis, 15771 Athens, Greece
| | - George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis, 15781 Athens, Greece
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17
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Rutherford JC, Bahn YS, van den Berg B, Heitman J, Xue C. Nutrient and Stress Sensing in Pathogenic Yeasts. Front Microbiol 2019; 10:442. [PMID: 30930866 PMCID: PMC6423903 DOI: 10.3389/fmicb.2019.00442] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Accepted: 02/20/2019] [Indexed: 12/23/2022] Open
Abstract
More than 1.5 million fungal species are estimated to live in vastly different environmental niches. Despite each unique host environment, fungal cells sense certain fundamentally conserved elements, such as nutrients, pheromones and stress, for adaptation to their niches. Sensing these extracellular signals is critical for pathogens to adapt to the hostile host environment and cause disease. Hence, dissecting the complex extracellular signal-sensing mechanisms that aid in this is pivotal and may facilitate the development of new therapeutic approaches to control fungal infections. In this review, we summarize the current knowledge on how two important pathogenic yeasts, Candida albicans and Cryptococcus neoformans, sense nutrient availability, such as carbon sources, amino acids, and ammonium, and different stress signals to regulate their morphogenesis and pathogenicity in comparison with the non-pathogenic model yeast Saccharomyces cerevisiae. The molecular interactions between extracellular signals and their respective sensory systems are described in detail. The potential implication of analyzing nutrient and stress-sensing systems in antifungal drug development is also discussed.
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Affiliation(s)
- Julian C Rutherford
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Yong-Sun Bahn
- Department of Biotechnology, Yonsei University, Seoul, South Korea
| | - Bert van den Berg
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Joseph Heitman
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, United States
| | - Chaoyang Xue
- Public Health Research Institute, Rutgers University, Newark, NJ, United States.,Department of Molecular Genetics, Biochemistry and Microbiology, Rutgers University, Newark, NJ, United States
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18
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Calvete CL, Martho KF, Felizardo G, Paes A, Nunes JM, Ferreira CO, Vallim MA, Pascon RC. Amino acid permeases in Cryptococcus neoformans are required for high temperature growth and virulence; and are regulated by Ras signaling. PLoS One 2019; 14:e0211393. [PMID: 30682168 PMCID: PMC6347259 DOI: 10.1371/journal.pone.0211393] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 01/11/2019] [Indexed: 11/22/2022] Open
Abstract
Cryptococcosis is an Invasive Fungal Infection (IFI) caused by Cryptococcus neoformans, mainly in immunocompromised patients. Therapeutic failure due to pathogen drug resistance, treatment inconstancy and few antifungal options is a problem. The study of amino acid biosynthesis and uptake represents an opportunity to explore possible development of novel antifungals. C. neoformans has 10 amino acids permeases, two of them (Aap3 and Aap7) not expressed at the conditions tested, and five were studied previously (Aap2, Aap4, Aap5, Mup1 and Mup3). Our previous results showed that Aap4 and Aap5 are major permeases with overlapping functions. The aap4Δ/aap5Δ double mutant fails to grow in amino acids as sole nitrogen source and is avirulent in animal model. Here, we deleted the remaining amino acid permeases (AAP1, AAP6, AAP8) that showed gene expression modulation by nutritional condition and created a double mutant (aap1Δ/aap2Δ). We studied the virulence attributes of these mutants and explored the regulatory mechanism behind amino acid uptake in C. neoformans. The aap1Δ/aap2Δ strain had reduced growth at 37°C in L-amino acids, reduced capsule production and was hypovirulent in the Galleria mellonella animal model. Our data, along with previous studies, (i) complement the analysis for all 10 amino acid permeases mutants, (ii) corroborate the idea that these transporters behave as global permeases, (iii) are required during heat and nutritional stress, and (iv) are important for virulence. Our study also indicates a new possible link between Ras1 signaling and amino acids uptake.
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Affiliation(s)
- Crislaine Lambiase Calvete
- Universidade de São Paulo, Biotechnology Graduate Program, São Paulo, SP, Brazil
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Kevin Felipe Martho
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Gabrielle Felizardo
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Alexandre Paes
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - João Miguel Nunes
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Camila Oliveira Ferreira
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Marcelo A. Vallim
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
| | - Renata C. Pascon
- Universidade Federal de São Paulo, Campus Diadema, Department of Biological Sciences, Diadema, SP, Brazil
- * E-mail:
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19
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Zhang P, Hu X. Metabolic engineering of arginine permeases to reduce the formation of urea in Saccharomyces cerevisiae. World J Microbiol Biotechnol 2018. [DOI: 10.1007/s11274-018-2430-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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20
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Steyfkens F, Zhang Z, Van Zeebroeck G, Thevelein JM. Multiple Transceptors for Macro- and Micro-Nutrients Control Diverse Cellular Properties Through the PKA Pathway in Yeast: A Paradigm for the Rapidly Expanding World of Eukaryotic Nutrient Transceptors Up to Those in Human Cells. Front Pharmacol 2018; 9:191. [PMID: 29662449 PMCID: PMC5890159 DOI: 10.3389/fphar.2018.00191] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2018] [Accepted: 02/20/2018] [Indexed: 12/17/2022] Open
Abstract
The nutrient composition of the medium has dramatic effects on many cellular properties in the yeast Saccharomyces cerevisiae. In addition to the well-known specific responses to starvation for an essential nutrient, like nitrogen or phosphate, the presence of fermentable sugar or a respirative carbon source leads to predominance of fermentation or respiration, respectively. Fermenting and respiring cells also show strong differences in other properties, like storage carbohydrate levels, general stress tolerance and cellular growth rate. However, the main glucose repression pathway, which controls the switch between respiration and fermentation, is not involved in control of these properties. They are controlled by the protein kinase A (PKA) pathway. Addition of glucose to respiring yeast cells triggers cAMP synthesis, activation of PKA and rapid modification of its targets, like storage carbohydrate levels, general stress tolerance and growth rate. However, starvation of fermenting cells in a glucose medium for any essential macro- or micro-nutrient counteracts this effect, leading to downregulation of PKA and its targets concomitant with growth arrest and entrance into G0. Re-addition of the lacking nutrient triggers rapid activation of the PKA pathway, without involvement of cAMP as second messenger. Investigation of the sensing mechanism has revealed that the specific high-affinity nutrient transporter(s) induced during starvation function as transporter-receptors or transceptors for rapid activation of PKA upon re-addition of the missing substrate. In this way, transceptors have been identified for amino acids, ammonium, phosphate, sulfate, iron, and zinc. We propose a hypothesis for regulation of PKA activity by nutrient transceptors to serve as a conceptual framework for future experimentation. Many properties of transceptors appear to be similar to those of classical receptors and nutrient transceptors may constitute intermediate forms in the development of receptors from nutrient transporters during evolution. The nutrient-sensing transceptor system in yeast for activation of the PKA pathway has served as a paradigm for similar studies on candidate nutrient transceptors in other eukaryotes and we succinctly discuss the many examples of transceptors that have already been documented in other yeast species, filamentous fungi, plants, and animals, including the examples in human cells.
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Affiliation(s)
- Fenella Steyfkens
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
| | - Zhiqiang Zhang
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
| | - Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven, Belgium.,Center for Microbiology, VIB, Flanders, Belgium
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21
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Schrevens S, Van Zeebroeck G, Riedelberger M, Tournu H, Kuchler K, Van Dijck P. Methionine is required for cAMP-PKA-mediated morphogenesis and virulence of Candida albicans. Mol Microbiol 2018; 108:258-275. [PMID: 29453849 DOI: 10.1111/mmi.13933] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/14/2018] [Indexed: 12/24/2022]
Abstract
Candida albicans is a major human fungal pathogen, causing superficial, as well as life-threatening invasive infections. Therefore, it has to adequately sense and respond to the host defense by expressing appropriate virulence attributes. The most important virulence factor of C. albicans is the yeast-to-hyphae morphogenetic switch, which can be induced by numerous environmental cues, including the amino acid methionine. Here, we show an essential role for methionine permease Mup1 in methionine-induced morphogenesis, biofilm formation, survival inside macrophages and virulence. Furthermore, we demonstrate that this process requires conversion of methionine into S-adenosyl methionine (SAM) and its decarboxylation by Spe2. The resulting amino-propyl group is then used for biosynthesis of polyamines, which have been shown to activate adenylate cyclase. Inhibition of the SPE2 SAM decarboxylase gene strongly impairs methionine-induced morphogenesis on specific media and significantly delays virulence in the mouse systemic infection model system. Further proof of the connection between methionine uptake and initial metabolism and the cAMP-PKA pathway was obtained by showing that both Mup1 and Spe2 are required for cAMP production in response to methionine. Our results suggest that amino acid transport and further metabolism are interesting therapeutic targets as inhibitors of this may prevent the morphogenetic switch, thereby preventing virulence.
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Affiliation(s)
- Sanne Schrevens
- VIB - KU Leuven Center for Microbiology, Leuven 3001, Belgium.,Laboratory of Molecular Cell Biology, KU Leuven, Leuven 3001, Belgium
| | - Griet Van Zeebroeck
- VIB - KU Leuven Center for Microbiology, Leuven 3001, Belgium.,Laboratory of Molecular Cell Biology, KU Leuven, Leuven 3001, Belgium
| | - Michael Riedelberger
- Medical University of Vienna, Center of Medical Biochemistry, Max F. Perutz Laboratories, Campus Vienna Biocenter, Vienna, Austria
| | - Hélène Tournu
- VIB - KU Leuven Center for Microbiology, Leuven 3001, Belgium.,Laboratory of Molecular Cell Biology, KU Leuven, Leuven 3001, Belgium
| | - Karl Kuchler
- Medical University of Vienna, Center of Medical Biochemistry, Max F. Perutz Laboratories, Campus Vienna Biocenter, Vienna, Austria
| | - Patrick Van Dijck
- VIB - KU Leuven Center for Microbiology, Leuven 3001, Belgium.,Laboratory of Molecular Cell Biology, KU Leuven, Leuven 3001, Belgium
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22
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Wyant GA, Abu-Remaileh M, Wolfson RL, Chen WW, Freinkman E, Danai LV, Vander Heiden MG, Sabatini DM. mTORC1 Activator SLC38A9 Is Required to Efflux Essential Amino Acids from Lysosomes and Use Protein as a Nutrient. Cell 2017; 171:642-654.e12. [PMID: 29053970 DOI: 10.1016/j.cell.2017.09.046] [Citation(s) in RCA: 330] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Revised: 07/18/2017] [Accepted: 09/25/2017] [Indexed: 12/17/2022]
Abstract
The mTORC1 kinase is a master growth regulator that senses many environmental cues, including amino acids. Activation of mTORC1 by arginine requires SLC38A9, a poorly understood lysosomal membrane protein with homology to amino acid transporters. Here, we validate that SLC38A9 is an arginine sensor for the mTORC1 pathway, and we uncover an unexpectedly central role for SLC38A9 in amino acid homeostasis. SLC38A9 mediates the transport, in an arginine-regulated fashion, of many essential amino acids out of lysosomes, including leucine, which mTORC1 senses through the cytosolic Sestrin proteins. SLC38A9 is necessary for leucine generated via lysosomal proteolysis to exit lysosomes and activate mTORC1. Pancreatic cancer cells, which use macropinocytosed protein as a nutrient source, require SLC38A9 to form tumors. Thus, through SLC38A9, arginine serves as a lysosomal messenger that couples mTORC1 activation to the release from lysosomes of the essential amino acids needed to drive cell growth.
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Affiliation(s)
- Gregory A Wyant
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Monther Abu-Remaileh
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA
| | - Rachel L Wolfson
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Harvard Medical School M.D.-Ph.D. Program, Daniel C. Tosteson Medical Education Center, 260 Longwood Avenue, Boston, MA 02115, USA
| | - Walter W Chen
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Harvard Medical School M.D.-Ph.D. Program, Daniel C. Tosteson Medical Education Center, 260 Longwood Avenue, Boston, MA 02115, USA
| | - Elizaveta Freinkman
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA
| | - Laura V Danai
- Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA
| | - Matthew G Vander Heiden
- Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA; Dana-Farber Cancer Institute, Boston, MA 02115, USA
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA; Department of Biology, Massachusetts Institute of Technology, 9 Cambridge Center, Cambridge, MA 02142, USA; Howard Hughes Medical Institute, Cambridge, MA 02139, USA; Koch Institute for Integrative Cancer Research, 77 Massachusetts Avenue, Cambridge, MA 02139, USA; Broad Institute of MIT and Harvard, 7 Cambridge Center, Cambridge, MA 02142, USA.
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23
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Dinkeloo K, Boyd S, Pilot G. Update on amino acid transporter functions and on possible amino acid sensing mechanisms in plants. Semin Cell Dev Biol 2017; 74:105-113. [PMID: 28705659 DOI: 10.1016/j.semcdb.2017.07.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 06/30/2017] [Accepted: 07/07/2017] [Indexed: 12/25/2022]
Abstract
Amino acids are essential components of plant metabolism, not only as constituents of proteins, but also as precursors of important secondary metabolites and as carriers of organic nitrogen between the organs of the plant. Transport across intracellular membranes and translocation of amino acids within the plant is mediated by membrane amino acid transporters. The past few years have seen the identification of a new family of amino acid transporters in Arabidopsis, the characterization of intracellular amino acid transporters, and the discovery of new roles for already known proteins. While amino acid metabolism needs to be tightly coordinated with amino acid transport activity and carbohydrate metabolism, no gene involved in amino acid sensing in plants has been unequivocally identified to date. This review aims at summarizing the recent data accumulated on the identity and function of amino acid transporters in plants, and discussing the possible identity of amino acid sensors based on data from other organisms.
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Affiliation(s)
- Kasia Dinkeloo
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24060, USA
| | - Shelton Boyd
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24060, USA
| | - Guillaume Pilot
- Department of Plant Pathology, Physiology and Weed Science, Virginia Tech, Blacksburg, VA 24060, USA.
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24
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Schothorst J, Zeebroeck GV, Thevelein JM. Identification of Ftr1 and Zrt1 as iron and zinc micronutrient transceptors for activation of the PKA pathway in Saccharomyces cerevisiae. MICROBIAL CELL 2017; 4:74-89. [PMID: 28357393 PMCID: PMC5349193 DOI: 10.15698/mic2017.03.561] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Multiple types of nutrient transceptors, membrane proteins that combine a
transporter and receptor function, have now been established in a variety of
organisms. However, so far all established transceptors utilize one of the
macronutrients, glucose, amino acids, ammonium, nitrate, phosphate or sulfate,
as substrate. This is also true for the Saccharomyces
cerevisiae transceptors mediating activation of the PKA pathway
upon re-addition of a macronutrient to glucose-repressed cells starved for that
nutrient, re-establishing a fermentable growth medium. We now show that the
yeast high-affinity iron transporter Ftr1 and high-affinity zinc transporter
Zrt1 function as transceptors for the micronutrients iron and zinc.
We show that replenishment of iron to iron-starved cells or zinc to
zinc-starved cells triggers within 1-2 minutes a rapid surge in trehalase
activity, a well-established PKA target. The activation with iron is dependent
on Ftr1 and with zinc on Zrt1, and we show that it is independent of
intracellular iron and zinc levels. Similar to the transceptors for
macronutrients, Ftr1 and Zrt1 are strongly induced upon iron and zinc
starvation, respectively, and they are rapidly downregulated by
substrate-induced endocytosis. Our results suggest that transceptor-mediated
signaling to the PKA pathway may occur in all cases where glucose-repressed
yeast cells have been starved first for an essential nutrient, causing arrest of
growth and low activity of the PKA pathway, and subsequently replenished with
the lacking nutrient to re-establish a fermentable growth medium. The broadness
of the phenomenon also makes it likely that nutrient transceptors use a common
mechanism for signaling to the PKA pathway.
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Affiliation(s)
- Joep Schothorst
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium. ; Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Griet V Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium. ; Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium. ; Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
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25
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Abstract
Cells need to communicate with their environment in order to obtain nutrients, grow, divide and respond to signals related to adaptation in changing physiological conditions or stress. A very basic question in biology is how cells, especially of those organisms living in rapidly changing habitats, sense their environment. Apparently, this question is of particular importance to all free-living microorganisms. The critical role of receptors, transporters and channels, transmembrane proteins located in the plasma membrane of all types of cells, in signaling environmental changes is well established. A relative newcomer in environment sensing are the so called transceptors, membrane proteins that possess both solute transport and receptor-like signaling activities. Now, the transceptor concept is further enlarged to include micronutrient sensing via the iron and zinc high-affinity transporters of Saccharomyces cerevisiae. Interestingly, what seems to underline the transport and/or sensing function of receptors, transporters and transceptors is ligand-induced conformational alterations recognized by downstream intracellular effectors.
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Affiliation(s)
- George Diallinas
- Department of Biology, National and Kapodistrian University of Athens, Panepistimioupolis 15784, Athens, Greece
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26
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Van Dijck P, Brown NA, Goldman GH, Rutherford J, Xue C, Van Zeebroeck G. Nutrient Sensing at the Plasma Membrane of Fungal Cells. Microbiol Spectr 2017; 5:10.1128/microbiolspec.funk-0031-2016. [PMID: 28256189 PMCID: PMC11687466 DOI: 10.1128/microbiolspec.funk-0031-2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Indexed: 12/25/2022] Open
Abstract
To respond to the changing environment, cells must be able to sense external conditions. This is important for many processes including growth, mating, the expression of virulence factors, and several other regulatory effects. Nutrient sensing at the plasma membrane is mediated by different classes of membrane proteins that activate downstream signaling pathways: nontransporting receptors, transceptors, classical and nonclassical G-protein-coupled receptors, and the newly defined extracellular mucin receptors. Nontransporting receptors have the same structure as transport proteins, but have lost the capacity to transport while gaining a receptor function. Transceptors are transporters that also function as a receptor, because they can rapidly activate downstream signaling pathways. In this review, we focus on these four types of fungal membrane proteins. We mainly discuss the sensing mechanisms relating to sugars, ammonium, and amino acids. Mechanisms for other nutrients, such as phosphate and sulfate, are discussed briefly. Because the model yeast Saccharomyces cerevisiae has been the most studied, especially regarding these nutrient-sensing systems, each subsection will commence with what is known in this species.
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Affiliation(s)
- Patrick Van Dijck
- VIB-KU Leuven Center for Microbiology KU Leuven, Flanders, Belgium
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven, Belgium
| | - Neil Andrew Brown
- Plant Biology and Crop Science, Rothamsted Research, Harpenden, AL5 2JQ, United Kingdom
| | - Gustavo H Goldman
- Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
| | - Julian Rutherford
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Chaoyang Xue
- Public Health Research Institute, Department of Microbiology, Biochemistry and Molecular Genetics, Rutgers Biomedical and Health Sciences, Newark, NJ 07103
| | - Griet Van Zeebroeck
- VIB-KU Leuven Center for Microbiology KU Leuven, Flanders, Belgium
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven, Belgium
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Wang B, Li J, Gao J, Cai P, Han X, Tian C. Identification and characterization of the glucose dual-affinity transport system in Neurospora crassa: pleiotropic roles in nutrient transport, signaling, and carbon catabolite repression. BIOTECHNOLOGY FOR BIOFUELS 2017; 10:17. [PMID: 28115989 PMCID: PMC5244594 DOI: 10.1186/s13068-017-0705-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Accepted: 01/07/2017] [Indexed: 05/07/2023]
Abstract
BACKGROUND The glucose dual-affinity transport system (low- and high-affinity) is a conserved strategy used by microorganisms to cope with natural fluctuations in nutrient availability in the environment. The glucose-sensing and uptake processes are believed to be tightly associated with cellulase expression regulation in cellulolytic fungi. However, both the identities and functions of the major molecular components of this evolutionarily conserved system in filamentous fungi remain elusive. Here, we systematically identified and characterized the components of the glucose dual-affinity transport system in the model fungus Neurospora crassa. RESULTS Using RNA sequencing coupled with functional transport analyses, we assigned GLT-1 (Km = 18.42 ± 3.38 mM) and HGT-1/-2 (Km = 16.13 ± 0.95 and 98.97 ± 22.02 µM) to the low- and high-affinity glucose transport systems, respectively. The high-affinity transporters hgt-1/-2 complemented a moderate growth defect under high glucose when glt-1 was deleted. Simultaneous deletion of hgt-1/-2 led to extensive derepression of genes for plant cell wall deconstruction in cells grown on cellulose. The suppression by HGT-1/-2 was connected to both carbon catabolite repression (CCR) and the cyclic adenosine monophosphate-protein kinase A pathway. Alteration of a residue conserved across taxa in hexose transporters resulted in a loss of glucose-transporting function, whereas CCR signal transduction was retained, indicating dual functions for HGT-1/-2 as "transceptors." CONCLUSIONS In this study, GLT-1 and HGT-1/-2 were identified as the key components of the glucose dual-affinity transport system, which plays diverse roles in glucose transport and carbon metabolism. Given the wide conservation of the glucose dual-affinity transport system across fungal species, the identification of its components and their pleiotropic roles in this study shed important new light on the molecular basis of nutrient transport, signaling, and plant cell wall degradation in fungi.
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Affiliation(s)
- Bang Wang
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
- School of Ophthalmology and Optometry, Eye Hospital, State Key Laboratory Cultivation Base and Key Laboratory of Vision Science, Ministry of Health and Zhejiang Provincial Key Laboratory of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, 325027 China
| | - Jingen Li
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Jingfang Gao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- School of Life Sciences, Heilongjiang University, Harbin, 150080 Heilongjiang China
| | - Pengli Cai
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
| | - Xiaoyun Han
- School of Life Sciences, Heilongjiang University, Harbin, 150080 Heilongjiang China
| | - Chaoguang Tian
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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Characterization of the Candida albicans Amino Acid Permease Family: Gap2 Is the Only General Amino Acid Permease and Gap4 Is an S-Adenosylmethionine (SAM) Transporter Required for SAM-Induced Morphogenesis. mSphere 2016; 1:mSphere00284-16. [PMID: 28028545 PMCID: PMC5177730 DOI: 10.1128/msphere.00284-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 11/28/2016] [Indexed: 11/20/2022] Open
Abstract
Candida albicans is a commensal organism that can thrive in many niches in its human host. The environmental conditions at these different niches differ quite a bit, and this fungus must be able to sense these changes and adapt its metabolism to them. Apart from glucose and other sugars, the uptake of amino acids is very important. This is underscored by the fact that the C. albicans genome encodes 6 orthologues of the Saccharomyces. cerevisiae general amino acid permease Gap1 and many other amino acid transporters. In this work, we characterize these six permeases and we show that C. albicans Gap2 is the functional orthologue of ScGap1 and that C. albicans Gap4 is an orthologue of ScSam3, an S-adenosylmethionine (SAM) transporter. Furthermore, we show that Gap4 is required for SAM-induced morphogenesis, an important virulence factor of C. albicans. Amino acids are key sources of nitrogen for growth of Candida albicans. In order to detect and take up these amino acids from a broad range of different and changing nitrogen sources inside the host, this fungus must be able to adapt via its expression of genes for amino acid uptake and further metabolism. We analyzed six C. albicans putative general amino acid permeases based on their homology to the Saccharomyces cerevisiae Gap1 general amino acid permease. We generated single- and multiple-deletion strains and found that, based on growth assays and transcriptional or posttranscriptional regulation, Gap2 is the functional orthologue to ScGap1, with broad substrate specificity. Expression analysis showed that expression of all GAP genes is under control of the Csy1 amino acid sensor, which is different from the situation in S. cerevisiae, where the expression of ScGAP1 is not regulated by Ssy1. We show that Gap4 is the functional orthologue of ScSam3, the only S-adenosylmethionine (SAM) transporter in S. cerevisiae, and we report that Gap4 is required for SAM-induced morphogenesis. IMPORTANCECandida albicans is a commensal organism that can thrive in many niches in its human host. The environmental conditions at these different niches differ quite a bit, and this fungus must be able to sense these changes and adapt its metabolism to them. Apart from glucose and other sugars, the uptake of amino acids is very important. This is underscored by the fact that the C. albicans genome encodes 6 orthologues of the Saccharomyces. cerevisiae general amino acid permease Gap1 and many other amino acid transporters. In this work, we characterize these six permeases and we show that C. albicans Gap2 is the functional orthologue of ScGap1 and that C. albicans Gap4 is an orthologue of ScSam3, an S-adenosylmethionine (SAM) transporter. Furthermore, we show that Gap4 is required for SAM-induced morphogenesis, an important virulence factor of C. albicans.
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Zhang P, Du G, Zou H, Chen J, Xie G, Shi Z, Zhou J. Effects of three permeases on arginine utilization in Saccharomyces cerevisiae. Sci Rep 2016; 6:20910. [PMID: 26865023 PMCID: PMC4750040 DOI: 10.1038/srep20910] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 01/13/2016] [Indexed: 11/09/2022] Open
Abstract
Arginine plays an important role in cellular function and metabolism. Arginine uptake mainly occurs through three amino acid permeases, Alp1p, Gap1p and Can1p, which act as both transporters and receptors for amino acid utilization. In this study, seven mutants were constructed with different combinations of permease deficiencies that inhibit arginine utilization. Their effects on arginine metabolism were measured. The three amino acid permeases were also individually overexpressed in wild-type (WT), Δalp1Δgap1Δcan1 and Δnpr1 strains. The growth and arginine utilization of Δcan1, Δgap1Δcan1 and Δalp1Δgap1Δcan1 mutants were suppressed in YNB medium when arginine was the sole nitrogen source. Meanwhile, overexpression of Alp1p and Can1p enhanced growth and arginine utilization in WT, Δalp1Δgap1Δcan1 and Δnpr1. Besides, overexpression of Can1p caused a 26.7% increase in OD600 and 29.3% increase in arginine utilization compared to that of Alp1p in Δalp1Δgap1Δcan1. Transcription analysis showed that the effects of three amino acid permeases on the arginine utilization and the regulation of related genes, were tightly related to their individual characteristics. However, their overall effects were different for different combinations of mutants. The results presented here suggest some possible synergistic effects of different amino acid permeases on regulation of amino acid utilization and metabolism.
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Affiliation(s)
- Peng Zhang
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Guocheng Du
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Huijun Zou
- Zhejiang Guyuelongshan Shaoxing Wine Company, 13 Yangjiang Road, Shaoxing, Zhejiang, China
| | - Jian Chen
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Guangfa Xie
- Zhejiang Guyuelongshan Shaoxing Wine Company, 13 Yangjiang Road, Shaoxing, Zhejiang, China
| | - Zhongping Shi
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
| | - Jingwen Zhou
- Key Laboratory of Industrial Biotechnology, Ministry of Education and School of Biotechnology, Jiangnan University, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
- Synergetic Innovation Center of Food Safety and Nutrition, 1800 Lihu Road, Wuxi, Jiangsu 214122, China
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30
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Chen L, Zhang YH, Huang T, Cai YD. Identifying novel protein phenotype annotations by hybridizing protein-protein interactions and protein sequence similarities. Mol Genet Genomics 2016; 291:913-34. [PMID: 26728152 DOI: 10.1007/s00438-015-1157-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 12/08/2015] [Indexed: 01/18/2023]
Abstract
Studies of protein phenotypes represent a central challenge of modern genetics in the post-genome era because effective and accurate investigation of protein phenotypes is one of the most critical procedures to identify functional biological processes in microscale, which involves the analysis of multifactorial traits and has greatly contributed to the development of modern biology in the post genome era. Therefore, we have developed a novel computational method that identifies novel proteins associated with certain phenotypes in yeast based on the protein-protein interaction network. Unlike some existing network-based computational methods that identify the phenotype of a query protein based on its direct neighbors in the local network, the proposed method identifies novel candidate proteins for a certain phenotype by considering all annotated proteins with this phenotype on the global network using a shortest path (SP) algorithm. The identified proteins are further filtered using both a permutation test and their interactions and sequence similarities to annotated proteins. We compared our method with another widely used method called random walk with restart (RWR). The biological functions of proteins for each phenotype identified by our SP method and the RWR method were analyzed and compared. The results confirmed a large proportion of our novel protein phenotype annotation, and the RWR method showed a higher false positive rate than the SP method. Our method is equally effective for the prediction of proteins involving in all the eleven clustered yeast phenotypes with a quite low false positive rate. Considering the universality and generalizability of our supporting materials and computing strategies, our method can further be applied to study other organisms and the new functions we predicted can provide pertinent instructions for the further experimental verifications.
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Affiliation(s)
- Lei Chen
- School of Life Sciences, Shanghai University, Shanghai, 200444, People's Republic of China. .,College of Information Engineering, Shanghai Maritime University, Shanghai, 201306, People's Republic of China.
| | - Yu-Hang Zhang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, People's Republic of China
| | - Tao Huang
- Institute of Health Sciences, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, 200031, People's Republic of China
| | - Yu-Dong Cai
- School of Life Sciences, Shanghai University, Shanghai, 200444, People's Republic of China.
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Sugar and Glycerol Transport in Saccharomyces cerevisiae. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:125-168. [PMID: 26721273 DOI: 10.1007/978-3-319-25304-6_6] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
In Saccharomyces cerevisiae the process of transport of sugar substrates into the cell comprises a complex network of transporters and interacting regulatory mechanisms. Members of the large family of hexose (HXT) transporters display uptake efficiencies consistent with their environmental expression and play physiological roles in addition to feeding the glycolytic pathway. Multiple glucose-inducing and glucose-independent mechanisms serve to regulate expression of the sugar transporters in yeast assuring that expression levels and transporter activity are coordinated with cellular metabolism and energy needs. The expression of sugar transport activity is modulated by other nutritional and environmental factors that may override glucose-generated signals. Transporter expression and activity is regulated transcriptionally, post-transcriptionally and post-translationally. Recent studies have expanded upon this suite of regulatory mechanisms to include transcriptional expression fine tuning mediated by antisense RNA and prion-based regulation of transcription. Much remains to be learned about cell biology from the continued analysis of this dynamic process of substrate acquisition.
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32
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Function and Regulation of Fungal Amino Acid Transporters: Insights from Predicted Structure. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:69-106. [PMID: 26721271 DOI: 10.1007/978-3-319-25304-6_4] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Amino acids constitute a major nutritional source for probably all fungi. Studies of model species such as the yeast Saccharomyces cerevisiae and the filamentous fungus Aspergillus nidulans have shown that they possess multiple amino acid transporters. These proteins belong to a limited number of superfamilies, now defined according to protein fold in addition to sequence criteria, and differ in subcellular location, substrate specificity range, and regulation. Structural models of several of these transporters have recently been built, and the detailed molecular mechanisms of amino acid recognition and translocation are now being unveiled. Furthermore, the particular conformations adopted by some of these transporters in response to amino acid binding appear crucial to promoting their ubiquitin-dependent endocytosis and/or to triggering signaling responses. We here summarize current knowledge, derived mainly from studies on S. cerevisiae and A. nidulans, about the transport activities, regulation, and sensing role of fungal amino acid transporters, in relation to predicted structure.
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33
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Pfannmüller A, Wagner D, Sieber C, Schönig B, Boeckstaens M, Marini AM, Tudzynski B. The General Amino Acid Permease FfGap1 of Fusarium fujikuroi Is Sorted to the Vacuole in a Nitrogen-Dependent, but Npr1 Kinase-Independent Manner. PLoS One 2015; 10:e0125487. [PMID: 25909858 PMCID: PMC4409335 DOI: 10.1371/journal.pone.0125487] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Accepted: 03/14/2015] [Indexed: 12/18/2022] Open
Abstract
The rice pathogenic fungus Fusarium fujikuroi is well known for the production of a broad spectrum of secondary metabolites (SMs) such as gibberellic acids (GAs), mycotoxins and pigments. The biosynthesis of most of these SMs strictly depends on nitrogen availability and of the activity of permeases of nitrogen sources, e.g. the ammonium and amino acid permeases. One of the three ammonium permeases, MepB, was recently shown to act not only as a transporter but also as a nitrogen sensor affecting the production of nitrogen-repressed SMs. Here we describe the identification of a general amino acid permease, FfGap1, among the 99 putative amino acid permeases (AAPs) in the genome of F. fujikuroi. FfGap1 is able to fully restore growth of the yeast gap1∆ mutant on several amino acids including citrulline and tryptophane. In S. cerevisiae, Gap1 activity is regulated by shuttling between the plasma membrane (nitrogen limiting conditions) and the vacuole (nitrogen sufficiency), which we also show for FfGap1. In yeast, the Npr1 serine/threonine kinase stabilizes the Gap1 position at the plasma membrane. Here, we identified and characterized three NPR1-homologous genes, encoding the putative protein kinases FfNpr1-1, FfNpr1-2 and FfNpr1-3 with significant similarity to yeast Npr1. Complementation of the yeast npr1Δ mutant with each of the three F. fujikuroi NPR1 homologues, resulted in partial restoration of ammonium, arginine and proline uptake by FfNPR1-1 while none of the three kinases affect growth on different nitrogen sources and nitrogen-dependent sorting of FfGap1 in F. fujikuroi. However, exchange of the putative ubiquitin-target lysine 9 (K9A) and 15 (K15A) residues of FfGap1 resulted in extended localization to the plasma membrane and increased protein stability independently of nitrogen availability. These data suggest a similar regulation of FfGap1 by nitrogen-dependent ubiquitination, but differences regarding the role of Fusarium Npr1 homologues compared to yeast.
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Affiliation(s)
- Andreas Pfannmüller
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Dominik Wagner
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Christian Sieber
- Institute of Bioinformatics and Systems Biology, Helmholtz Zentrum München, German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Birgit Schönig
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Münster, Germany
| | - Mélanie Boeckstaens
- Laboratoire de Biologie du Transport Membranaire, Institut de Biologie et de Médecine Moléculaires, Université Libre de Bruxelles, Gosselies, Belgium
| | - Anna Maria Marini
- Laboratoire de Biologie du Transport Membranaire, Institut de Biologie et de Médecine Moléculaires, Université Libre de Bruxelles, Gosselies, Belgium
| | - Bettina Tudzynski
- Institut für Biologie und Biotechnologie der Pflanzen, Westfälische Wilhelms-Universität Münster, Münster, Germany
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Kankipati HN, Rubio-Texeira M, Castermans D, Diallinas G, Thevelein JM. Sul1 and Sul2 sulfate transceptors signal to protein kinase A upon exit of sulfur starvation. J Biol Chem 2015; 290:10430-46. [PMID: 25724649 PMCID: PMC4400352 DOI: 10.1074/jbc.m114.629022] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Indexed: 11/24/2022] Open
Abstract
Sulfate is an essential nutrient with pronounced regulatory effects on cellular metabolism and proliferation. Little is known, however, about how sulfate is sensed by cells. Sul1 and Sul2 are sulfate transporters in the yeast Saccharomyces cerevisiae, strongly induced upon sulfur starvation and endocytosed upon the addition of sulfate. We reveal Sul1,2-dependent activation of PKA targets upon sulfate-induced exit from growth arrest after sulfur starvation. We provide two major arguments in favor of Sul1 and Sul2 acting as transceptors for signaling to PKA. First, the sulfate analogue, d-glucosamine 2-sulfate, acted as a non-transported agonist of signaling by Sul1 and Sul2. Second, mutagenesis to Gln of putative H+-binding residues, Glu-427 in Sul1 or Glu-443 in Sul2, abolished transport without affecting signaling. Hence, Sul1,2 can function as pure sulfate sensors. Sul1E427Q and Sul2E443Q are also deficient in sulfate-induced endocytosis, which can therefore be uncoupled from signaling. Overall, our data suggest that transceptors can undergo independent conformational changes, each responsible for triggering different downstream processes. The Sul1 and Sul2 transceptors are the first identified plasma membrane sensors for extracellular sulfate. High affinity transporters induced upon starvation for their substrate may generally act as transceptors during exit from starvation.
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Affiliation(s)
- Harish Nag Kankipati
- From the Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, the Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, and
| | - Marta Rubio-Texeira
- From the Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, the Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, and
| | - Dries Castermans
- From the Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, the Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, and
| | - George Diallinas
- the Faculty of Biology, University of Athens, Panepistimioupolis, Athens 15784, Greece
| | - Johan M Thevelein
- From the Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, the Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium, and
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35
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Diallinas G. Understanding transporter specificity and the discrete appearance of channel-like gating domains in transporters. Front Pharmacol 2014; 5:207. [PMID: 25309439 PMCID: PMC4162363 DOI: 10.3389/fphar.2014.00207] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 08/22/2014] [Indexed: 12/12/2022] Open
Abstract
Transporters are ubiquitous proteins mediating the translocation of solutes across cell membranes, a biological process involved in nutrition, signaling, neurotransmission, cell communication and drug uptake or efflux. Similarly to enzymes, most transporters have a single substrate binding-site and thus their activity follows Michaelis-Menten kinetics. Substrate binding elicits a series of structural changes, which produce a transporter conformer open toward the side opposite to the one from where the substrate was originally bound. This mechanism, involving alternate outward- and inward-facing transporter conformers, has gained significant support from structural, genetic, biochemical and biophysical approaches. Most transporters are specific for a given substrate or a group of substrates with similar chemical structure, but substrate specificity and/or affinity can vary dramatically, even among members of a transporter family that show high overall amino acid sequence and structural similarity. The current view is that transporter substrate affinity or specificity is determined by a small number of interactions a given solute can make within a specific binding site. However, genetic, biochemical and in silico modeling studies with the purine transporter UapA of the filamentous ascomycete Aspergillus nidulans have challenged this dogma. This review highlights results leading to a novel concept, stating that substrate specificity, but also transport kinetics and transporter turnover, are determined by subtle intramolecular interactions between a major substrate binding site and independent outward- or cytoplasmically-facing gating domains, analogous to those present in channels. This concept is supported by recent structural evidence from several, phylogenetically and functionally distinct transporter families. The significance of this concept is discussed in relationship to the role and potential exploitation of transporters in drug action.
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Van Zeebroeck G, Rubio-Texeira M, Schothorst J, Thevelein JM. Specific analogues uncouple transport, signalling, oligo-ubiquitination and endocytosis in the yeast Gap1 amino acid transceptor. Mol Microbiol 2014; 93:213-33. [PMID: 24852066 PMCID: PMC4285233 DOI: 10.1111/mmi.12654] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/20/2014] [Indexed: 12/14/2022]
Abstract
The Saccharomyces cerevisiae amino acid transceptor Gap1 functions as receptor for signalling to the PKA pathway and concomitantly undergoes substrate-induced oligo-ubiquitination and endocytosis. We have identified specific amino acids and analogues that uncouple to certain extent signalling, transport, oligo-ubiquitination and endocytosis. l-lysine, l-histidine and l-tryptophan are transported by Gap1 but do not trigger signalling. Unlike l-histidine, l-lysine triggers Gap1 oligo-ubiquitination without substantial induction of endocytosis. Two transported, non-metabolizable signalling agonists, β-alanine and d-histidine, are strong and weak inducers of Gap1 endocytosis, respectively, but both causing Gap1 oligo-ubiquitination. The non-signalling agonist, non-transported competitive inhibitor of Gap1 transport, l-Asp-γ-l-Phe, induces oligo-ubiquitination but no discernible endocytosis. The Km of l-citrulline transport is much lower than the threshold concentration for signalling and endocytosis. These results show that molecules can be transported without triggering signalling or substantial endocytosis, and that oligo-ubiquitination and endocytosis do not require signalling nor metabolism. Oligo-ubiquitination is required, but apparently not sufficient to trigger endocytosis. In addition, we demonstrate intracellular cross-induction of endocytosis of transport-defective Gap1Y395C by ubiquitination- and endocytosis-deficient Gap1K9R,K16R. Our results support the concept that different substrates bind to partially overlapping binding sites in the same general substrate-binding pocket of Gap1, triggering divergent conformations, resulting in different conformation-induced downstream processes.
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Affiliation(s)
- Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium; Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, Leuven-Heverlee, Flanders, B-3001, Belgium
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Usami Y, Uemura S, Mochizuki T, Morita A, Shishido F, Inokuchi JI, Abe F. Functional mapping and implications of substrate specificity of the yeast high-affinity leucine permease Bap2. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1838:1719-29. [PMID: 24699373 DOI: 10.1016/j.bbamem.2014.03.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/21/2014] [Accepted: 03/25/2014] [Indexed: 11/29/2022]
Abstract
Leucine is a major amino acid in nutrients and proteins and is also an important precursor of higher alcohols during brewing. In Saccharomyces cerevisiae, leucine uptake is mediated by multiple amino acid permeases, including the high-affinity leucine permease Bap2. Although BAP2 transcription has been extensively analyzed, the mechanisms by which a substrate is recognized and moves through the permease remain unknown. Recently, we determined 15 amino acid residues required for Tat2-mediated tryptophan import. Here we introduced homologous mutations into Bap2 amino acid residues and showed that 7 residues played a role in leucine import. Residues I109/G110/T111 and E305 were located within the putative α-helix break in TMD1 and TMD6, respectively, according to the structurally homologous Escherichia coli arginine/agmatine antiporter AdiC. Upon leucine binding, these α-helix breaks were assumed to mediate a conformational transition in Bap2 from an outward-open to a substrate-binding occluded state. Residues Y336 (TMD7) and Y181 (TMD3) were located near I109 and E305, respectively. Bap2-mediated leucine import was inhibited by some amino acids according to the following order of severity: phenylalanine, leucine>isoleucine>methionine, tyrosine>valine>tryptophan; histidine and asparagine had no effect. Moreover, this order of severity clearly coincided with the logP values (octanol-water partition coefficients) of all amino acids except tryptophan. This result suggests that the substrate partition efficiency to the buried Bap2 binding pocket is the primary determinant of substrate specificity rather than structural amino acid side chain recognition.
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Affiliation(s)
- Yuki Usami
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan
| | - Satsohi Uemura
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan
| | - Takahiro Mochizuki
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan
| | - Asami Morita
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan
| | - Fumi Shishido
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, Sendai, Japan
| | - Jin-ichi Inokuchi
- Division of Glycopathology, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, Sendai, Japan
| | - Fumiyoshi Abe
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan; Institute of Biogeosciences, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan.
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38
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Conrad M, Schothorst J, Kankipati HN, Van Zeebroeck G, Rubio-Texeira M, Thevelein JM. Nutrient sensing and signaling in the yeast Saccharomyces cerevisiae. FEMS Microbiol Rev 2014; 38:254-99. [PMID: 24483210 PMCID: PMC4238866 DOI: 10.1111/1574-6976.12065] [Citation(s) in RCA: 453] [Impact Index Per Article: 41.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2013] [Revised: 12/23/2013] [Accepted: 01/22/2014] [Indexed: 02/04/2023] Open
Abstract
The yeast Saccharomyces cerevisiae has been a favorite organism for pioneering studies on nutrient-sensing and signaling mechanisms. Many specific nutrient responses have been elucidated in great detail. This has led to important new concepts and insight into nutrient-controlled cellular regulation. Major highlights include the central role of the Snf1 protein kinase in the glucose repression pathway, galactose induction, the discovery of a G-protein-coupled receptor system, and role of Ras in glucose-induced cAMP signaling, the role of the protein synthesis initiation machinery in general control of nitrogen metabolism, the cyclin-controlled protein kinase Pho85 in phosphate regulation, nitrogen catabolite repression and the nitrogen-sensing target of rapamycin pathway, and the discovery of transporter-like proteins acting as nutrient sensors. In addition, a number of cellular targets, like carbohydrate stores, stress tolerance, and ribosomal gene expression, are controlled by the presence of multiple nutrients. The protein kinase A signaling pathway plays a major role in this general nutrient response. It has led to the discovery of nutrient transceptors (transporter receptors) as nutrient sensors. Major shortcomings in our knowledge are the relationship between rapid and steady-state nutrient signaling, the role of metabolic intermediates in intracellular nutrient sensing, and the identity of the nutrient sensors controlling cellular growth.
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Affiliation(s)
- Michaela Conrad
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU LeuvenLeuven-Heverlee, Flanders, Belgium
- Department of Molecular Microbiology, VIBLeuven-Heverlee, Flanders, Belgium
| | - Joep Schothorst
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU LeuvenLeuven-Heverlee, Flanders, Belgium
- Department of Molecular Microbiology, VIBLeuven-Heverlee, Flanders, Belgium
| | - Harish Nag Kankipati
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU LeuvenLeuven-Heverlee, Flanders, Belgium
- Department of Molecular Microbiology, VIBLeuven-Heverlee, Flanders, Belgium
| | - Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU LeuvenLeuven-Heverlee, Flanders, Belgium
- Department of Molecular Microbiology, VIBLeuven-Heverlee, Flanders, Belgium
| | - Marta Rubio-Texeira
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU LeuvenLeuven-Heverlee, Flanders, Belgium
- Department of Molecular Microbiology, VIBLeuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU LeuvenLeuven-Heverlee, Flanders, Belgium
- Department of Molecular Microbiology, VIBLeuven-Heverlee, Flanders, Belgium
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Saad S, Peter M, Dechant R. In scarcity and abundance: metabolic signals regulating cell growth. Physiology (Bethesda) 2014; 28:298-309. [PMID: 23997189 DOI: 10.1152/physiol.00005.2013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Although nutrient availability is a major driver of cell growth, and continuous adaptation to nutrient supply is critical for the development and survival of all organisms, the molecular mechanisms of nutrient sensing are only beginning to emerge. Here, we highlight recent advances in the field of nutrient sensing and discuss arising principles governing how metabolism might regulate growth-promoting pathways. In addition, we discuss signaling functions of metabolic enzymes not directly related to their metabolic activity.
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Affiliation(s)
- Shady Saad
- Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
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40
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Roy A, Kim JH. Endocytosis and vacuolar degradation of the yeast cell surface glucose sensors Rgt2 and Snf3. J Biol Chem 2014; 289:7247-7256. [PMID: 24451370 DOI: 10.1074/jbc.m113.539411] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Sensing and signaling the presence of extracellular glucose is crucial for the yeast Saccharomyces cerevisiae because of its fermentative metabolism, characterized by high glucose flux through glycolysis. The yeast senses glucose through the cell surface glucose sensors Rgt2 and Snf3, which serve as glucose receptors that generate the signal for induction of genes involved in glucose uptake and metabolism. Rgt2 and Snf3 detect high and low glucose concentrations, respectively, perhaps because of their different affinities for glucose. Here, we provide evidence that cell surface levels of glucose sensors are regulated by ubiquitination and degradation. The glucose sensors are removed from the plasma membrane through endocytosis and targeted to the vacuole for degradation upon glucose depletion. The turnover of the glucose sensors is inhibited in endocytosis defective mutants, and the sensor proteins with a mutation at their putative ubiquitin-acceptor lysine residues are resistant to degradation. Of note, the low affinity glucose sensor Rgt2 remains stable only in high glucose grown cells, and the high affinity glucose sensor Snf3 is stable only in cells grown in low glucose. In addition, constitutively active, signaling forms of glucose sensors do not undergo endocytosis, whereas signaling defective sensors are constitutively targeted for degradation, suggesting that the stability of the glucose sensors may be associated with their ability to sense glucose. Therefore, our findings demonstrate that the amount of glucose available dictates the cell surface levels of the glucose sensors and that the regulation of glucose sensors by glucose concentration may enable yeast cells to maintain glucose sensing activity at the cell surface over a wide range of glucose concentrations.
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Affiliation(s)
- Adhiraj Roy
- Department of Biochemistry and Molecular Medicine, George Washington University Medical Center, Washington, D.C. 20037
| | - Jeong-Ho Kim
- Department of Biochemistry and Molecular Medicine, George Washington University Medical Center, Washington, D.C. 20037.
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Zhang B, Pasini R, Dan H, Joshi N, Zhao Y, Leustek T, Zheng ZL. Aberrant gene expression in the Arabidopsis SULTR1;2 mutants suggests a possible regulatory role for this sulfate transporter in response to sulfur nutrient status. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2014; 77:185-97. [PMID: 24308460 DOI: 10.1111/tpj.12376] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 10/17/2013] [Accepted: 11/04/2013] [Indexed: 05/18/2023]
Abstract
Sulfur is required for the biosynthesis of cysteine, methionine and numerous other metabolites, and thus is critical for cellular metabolism and various growth and developmental processes. Plants are able to sense their physiological state with respect to sulfur availability, but the sensor remains to be identified. Here we report the isolation and characterization of two novel allelic mutants of Arabidopsis thaliana, sel1-15 and sel1-16, which show increased expression of a sulfur deficiency-activated gene β-glucosidase 28 (BGLU28). The mutants, which represent two different missense alleles of SULTR1;2, which encodes a high-affinity sulfate transporter, are defective in sulfate transport and as a result have a lower cellular sulfate level. However, when treated with a very high dose of sulfate, sel1-15 and sel1-16 accumulated similar amounts of internal sulfate and its metabolite glutathione (GSH) to wild-type, but showed higher expression of BGLU28 and other sulfur deficiency-activated genes than wild-type. Reduced sensitivity to inhibition of gene expression was also observed in the sel1 mutants when fed with the sulfate metabolites Cys and GSH. In addition, a SULTR1;2 knockout allele also exhibits reduced inhibition in response to sulfate, Cys and GSH, consistent with the phenotype of sel1-15 and sel1-16. Taken together, the genetic evidence suggests that, in addition to its known function as a high-affinity sulfate transporter, SULTR1;2 may have a regulatory role in response to sulfur nutrient status. The possibility that SULTR1;2 may function as a sensor of sulfur status or a component of a sulfur sensory mechanism is discussed.
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Affiliation(s)
- Bo Zhang
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY 10468, USA
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Zheng ZL, Zhang B, Leustek T. Transceptors at the boundary of nutrient transporters and receptors: a new role for Arabidopsis SULTR1;2 in sulfur sensing. FRONTIERS IN PLANT SCIENCE 2014; 5:710. [PMID: 25566284 PMCID: PMC4263312 DOI: 10.3389/fpls.2014.00710] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/26/2014] [Indexed: 05/03/2023]
Abstract
Plants have evolved a sophisticated mechanism to sense the extracellular sulfur (S) status so that sulfate transport and S assimilation/metabolism can be coordinated. Genetic, biochemical, and molecular studies in Arabidopsis over the past 10 years have started to shed some light on the regulatory mechanism of the S response. Key advances in transcriptional regulation (SLIM1, MYB, and miR395), involvement of hormones (auxin, cytokinin, and abscisic acid) and identification of putative sensors (OASTL and SULTR1;2) are highlighted here. Although our current view of S nutrient sensing and signaling remains fragmented, it is anticipated that through further studies a sensing and signaling network will be revealed in the near future.
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Affiliation(s)
- Zhi-Liang Zheng
- Plant Nutrient Signaling and Fruit Quality Improvement Laboratory, Citrus Research Institute, Southwest University, Chongqing, China
- Department of Biological Sciences, Lehman College, City University of New York, Bronx, NY, USA
- *Correspondence: Zhi-Liang Zheng, Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA e-mail: ; Thomas Leustek, Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ 08901, USA e-mail:
| | - Bo Zhang
- Plant Nutrient Signaling and Fruit Quality Improvement Laboratory, Citrus Research Institute, Southwest University, Chongqing, China
| | - Thomas Leustek
- Department of Plant Biology and Pathology, Rutgers University, New Brunswick, NJ, USA
- *Correspondence: Zhi-Liang Zheng, Department of Biological Sciences, Lehman College, City University of New York, 250 Bedford Park Boulevard West, Bronx, NY 10468, USA e-mail: ; Thomas Leustek, Department of Plant Biology and Pathology, Rutgers University, 59 Dudley Road, New Brunswick, NJ 08901, USA e-mail:
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Debailleul F, Trubbia C, Frederickx N, Lauwers E, Merhi A, Ruysschaert JM, André B, Govaerts C. Nitrogen catabolite repressible GAP1 promoter, a new tool for efficient recombinant protein production in S. cerevisiae. Microb Cell Fact 2013; 12:129. [PMID: 24369062 PMCID: PMC3880969 DOI: 10.1186/1475-2859-12-129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 12/18/2013] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Decades of work requiring heterologous expression of eukaryotic proteins have shown that no expression system can be considered as the panacea and the appropriate expression strategy is often protein-dependent. In a large number of cases, yeasts have proven to be reliable organisms for heterologous protein expression by combining eukaryotic cellular organization with the ease of use of simpler microorganisms. RESULTS During this work, a novel promoter system based on the nitrogen catabolite regulation has been developed to produce the general amino acid permease (Gap1) in its natural host, the yeast Saccharomyces cerevisiae. A simple purification protocol was also established that allows to purify milligrams of Gap1 from cells cultivated in a five liters bio-reactor. In order to test the ability of the system to be used for expression of other proteins, the yeast specific transporter of γ-aminobutyric acid (Uga4), a human vesicular transporter of glutamate (Vglut1) and a small secreted glycoprotein (MD-2) were also expressed using the nitrogen catabolite regulation. All proteins were fused to GFP and their presence and localization were confirmed by western blot analysis and fluorescence microscopy. CONCLUSIONS Our work shows that the nitrogen catabolite repressible GAP1 promoter can be used to obtain high levels of recombinant protein while allowing for large biomass production in S. cerevisiae. This approach can be used to express membrane and soluble proteins from higher eukaryotes (from yeast to human). Therefore, this system stands as a promising alternative to commonly used expression procedure in yeasts.
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Affiliation(s)
- Fabien Debailleul
- S.F.M.B., Université Libre de Bruxelles, Blvd. du Triomphe, Bâtiment BC, local 1C4.208, B-1050 Bruxelles, Belgium
| | - Cataldo Trubbia
- S.F.M.B., Université Libre de Bruxelles, Blvd. du Triomphe, Bâtiment BC, local 1C4.208, B-1050 Bruxelles, Belgium
| | - Nancy Frederickx
- S.F.M.B., Université Libre de Bruxelles, Blvd. du Triomphe, Bâtiment BC, local 1C4.208, B-1050 Bruxelles, Belgium
| | - Elsa Lauwers
- Lab Physiologie Moléculaire de la Cellule, Université Libre de Bruxelles, IBMM, rue des Pr. Jeener et Brachet, 12, 6041 Gosselies, Belgium
| | - Ahmad Merhi
- Lab Physiologie Moléculaire de la Cellule, Université Libre de Bruxelles, IBMM, rue des Pr. Jeener et Brachet, 12, 6041 Gosselies, Belgium
| | - Jean-Marie Ruysschaert
- S.F.M.B., Université Libre de Bruxelles, Blvd. du Triomphe, Bâtiment BC, local 1C4.208, B-1050 Bruxelles, Belgium
| | - Bruno André
- Lab Physiologie Moléculaire de la Cellule, Université Libre de Bruxelles, IBMM, rue des Pr. Jeener et Brachet, 12, 6041 Gosselies, Belgium
| | - Cédric Govaerts
- S.F.M.B., Université Libre de Bruxelles, Blvd. du Triomphe, Bâtiment BC, local 1C4.208, B-1050 Bruxelles, Belgium
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Yeast nutrient transceptors provide novel insight in the functionality of membrane transporters. Curr Genet 2013; 59:197-206. [PMID: 24114446 PMCID: PMC3824880 DOI: 10.1007/s00294-013-0413-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Revised: 09/17/2013] [Accepted: 09/30/2013] [Indexed: 11/21/2022]
Abstract
In the yeast Saccharomyces cerevisiae several nutrient transporters have been identified that possess an additional function as nutrient receptor. These transporters are induced when yeast cells are starved for their substrate, which triggers entry into stationary phase and acquirement of a low protein kinase A (PKA) phenotype. Re-addition of the lacking nutrient triggers exit from stationary phase and sudden activation of the PKA pathway, the latter being mediated by the nutrient transceptors. At the same time, the transceptors are ubiquitinated, endocytosed and sorted to the vacuole for breakdown. Investigation of the signaling function of the transceptors has provided a new read-out and new tools for gaining insight into the functionality of transporters. Identification of amino acid residues that bind co-transported ions in symporters has been challenging because the inactivation of transport by site-directed mutagenesis is not conclusive with respect to the cause of the inactivation. The discovery of nontransported agonists of the signaling function in transceptors has shown that transport is not required for signaling. Inactivation of transport with maintenance of signaling in transceptors supports that a true proton-binding residue was mutagenised. Determining the relationship between transport and induction of endocytosis has also been challenging, since inactivation of transport by mutagenesis easily causes loss of all affinity for the substrate. The use of analogues with different combinations of transport and signaling capacities has revealed that transport, ubiquitination and endocytosis can be uncoupled in several unexpected ways. The results obtained are consistent with transporters undergoing multiple substrate-induced conformational changes, which allow interaction with different accessory proteins to trigger specific downstream events.
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Scharff-Poulsen P, Pedersen PA. Saccharomyces cerevisiae-based platform for rapid production and evaluation of eukaryotic nutrient transporters and transceptors for biochemical studies and crystallography. PLoS One 2013; 8:e76851. [PMID: 24124599 PMCID: PMC3790737 DOI: 10.1371/journal.pone.0076851] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Accepted: 09/02/2013] [Indexed: 11/19/2022] Open
Abstract
To produce large quantities of high quality eukaryotic membrane proteins in Saccharomyces cerevisiae, we modified a high-copy vector to express membrane proteins C-terminally-fused to a Tobacco Etch Virus (TEV) protease detachable Green Fluorescent Protein (GFP)-8His tag, which facilitates localization, quantification, quality control, and purification. Using this expression system we examined the production of a human glucose transceptor and 11 nutrient transporters and transceptors from S. cerevisiae that have not previously been overexpressed in S. cerevisiae and purified. Whole-cell GFP-fluorescence showed that induction of GFP-fusion synthesis from a galactose-inducible promoter at 15°C resulted in stable accumulation of the fusions in the plasma membrane and in intracellular membranes. Expression levels of the 12 fusions estimated by GFP-fluorescence were in the range of 0.4 mg to 1.7 mg transporter pr. liter cell culture. A detergent screen showed that n-dodecyl-ß-D-maltopyranoside (DDM) is acceptable for solubilization of the membrane-integrated fusions. Extracts of solubilized membranes were prepared with this detergent and used for purifications by Ni-NTA affinity chromatography, which yielded partially purified full-length fusions. Most of the fusions were readily cleaved at a TEV protease site between the membrane protein and the GFP-8His tag. Using the yeast oligopeptide transporter Ptr2 as an example, we further demonstrate that almost pure transporters, free of the GFP-8His tag, can be achieved by TEV protease cleavage followed by reverse immobilized metal-affinity chromatography. The quality of the GFP-fusions was analysed by fluorescence size-exclusion chromatography. Membranes solubilized in DDM resulted in preparations containing aggregated fusions. However, 9 of the fusions solubilized in DDM in presence of cholesteryl hemisuccinate and specific substrates, yielded monodisperse preparations with only minor amounts of aggregated membrane proteins. In conclusion, we developed a new effective S. cerevisiae expression system that may be used for production of high-quality eukaryotic membrane proteins for functional and structural analysis.
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Affiliation(s)
- Peter Scharff-Poulsen
- Department of Biology, University of Copenhagen, Copenhagen, Denmark
- Center for Microbial Biotechnology, Department of Systems Biology, Technical University of Denmark, Kongens Lyngby, Denmark
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46
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De Michele R, Ast C, Loqué D, Ho CH, Andrade SLA, Lanquar V, Grossmann G, Gehne S, Kumke MU, Frommer WB. Fluorescent sensors reporting the activity of ammonium transceptors in live cells. eLife 2013; 2:e00800. [PMID: 23840931 PMCID: PMC3699834 DOI: 10.7554/elife.00800] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/18/2013] [Indexed: 01/14/2023] Open
Abstract
Ammonium serves as key nitrogen source and metabolic intermediate, yet excess causes toxicity. Ammonium uptake is mediated by ammonium transporters, whose regulation is poorly understood. While transport can easily be characterized in heterologous systems, measuring transporter activity in vivo remains challenging. Here we developed a simple assay for monitoring activity in vivo by inserting circularly-permutated GFP into conformation-sensitive positions of two plant and one yeast ammonium transceptors (‘AmTrac’ and ‘MepTrac’). Addition of ammonium to yeast cells expressing the sensors triggered concentration-dependent fluorescence intensity (FI) changes that strictly correlated with the activity of the transporter. Fluorescence-based activity sensors present a novel technology for monitoring the interaction of the transporters with their substrates, the activity of transporters and their regulation in vivo, which is particularly valuable in the context of analytes for which no radiotracers exist, as well as for cell-specific and subcellular transport processes that are otherwise difficult to track. DOI:http://dx.doi.org/10.7554/eLife.00800.001 Ammonium provides a vital source of nitrogen for bacteria, fungi and plants, and is produced by animals as a waste product of metabolism. High levels of ammonium can be toxic, so all organisms need to control their uptake or excretion of this substance. Ammonium transporters, which are highly conserved from bacteria to plants to humans, are essential for this process but, along with transporters in general, they are hard to study. Their activity can be examined in vitro by expressing them in heterologous systems—that is, in cells other than those in which they are naturally found. But in vivo studies must rely on indirect techniques such as monitoring radioactive isotopes or membrane potentials, and these cannot distinguish between the activity of ammonium transporters and uptake of ammonium through other routes. One approach that has been successful in other fields is the use of fluorescent proteins that can signal conformational changes—such as those that occur when a transporter is activated—by a shift in fluorescence. Green fluorescent protein (GFP) is a commonly used fluorescent indicator, and a particularly useful variant is ‘circularly permutated GFP’. This is GFP in which parts of the amino acid sequence have been rearranged without fundamentally changing the overall structure or function of the protein. Circularly permutated GFP can be fused to another protein in such a way that a conformational change in the second protein triggers a change in fluorescence that can be detected by fluorescence spectroscopy or microscopy. Now, De Michele et al. have applied this approach to the study of both plant and yeast ammonium transporters. They constructed a library of fusion proteins made up of circularly permutated GFP and an ammonium transporter from the plant Arabidopsis thaliana—and found one version that functioned normally as a transporter but also produced a detectable change in fluorescence that correlated precisely with transporter activity. De Michele et al. then used the same method to produce fluorescent indicator fusion proteins of two more ammonium transporters—a second isoform from Arabidopsis and one from yeast. These fluorescent sensors should be a great boon to researchers studying the ammonium transport system. Moreover, this approach could in theory be applied to other transporter proteins that are currently difficult to study, and so could help to open up research into a variety of transport processes. DOI:http://dx.doi.org/10.7554/eLife.00800.002
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Affiliation(s)
- Roberto De Michele
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States.,Institute of Plant Genetics, Italian National Research Council (CNR-IGV), Palermo, Italy
| | - Cindy Ast
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States.,NanoPolyPhotonik, Fraunhofer Institute for Applied Polymer Research, Potsdam-Golm, Germany
| | - Dominique Loqué
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, United States
| | - Cheng-Hsun Ho
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Susana LA Andrade
- Department of Biochemistry, Institute for Organic Chemistry and Biochemistry, and BIOSS Center for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Viviane Lanquar
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Guido Grossmann
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Sören Gehne
- Department of Physical Chemistry, Institute of Chemistry, University of Potsdam, Potsdam, Germany
| | - Michael U Kumke
- Department of Physical Chemistry, Institute of Chemistry, University of Potsdam, Potsdam, Germany
| | - Wolf B Frommer
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
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47
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De Michele R, Ast C, Loqué D, Ho CH, Andrade SLA, Lanquar V, Grossmann G, Gehne S, Kumke MU, Frommer WB. Fluorescent sensors reporting the activity of ammonium transceptors in live cells. eLife 2013; 2:e00800. [PMID: 23840931 DOI: 10.7554/elife.00800.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Accepted: 05/18/2013] [Indexed: 05/26/2023] Open
Abstract
Ammonium serves as key nitrogen source and metabolic intermediate, yet excess causes toxicity. Ammonium uptake is mediated by ammonium transporters, whose regulation is poorly understood. While transport can easily be characterized in heterologous systems, measuring transporter activity in vivo remains challenging. Here we developed a simple assay for monitoring activity in vivo by inserting circularly-permutated GFP into conformation-sensitive positions of two plant and one yeast ammonium transceptors ('AmTrac' and 'MepTrac'). Addition of ammonium to yeast cells expressing the sensors triggered concentration-dependent fluorescence intensity (FI) changes that strictly correlated with the activity of the transporter. Fluorescence-based activity sensors present a novel technology for monitoring the interaction of the transporters with their substrates, the activity of transporters and their regulation in vivo, which is particularly valuable in the context of analytes for which no radiotracers exist, as well as for cell-specific and subcellular transport processes that are otherwise difficult to track. DOI:http://dx.doi.org/10.7554/eLife.00800.001.
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Affiliation(s)
- Roberto De Michele
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
- Institute of Plant Genetics, Italian National Research Council (CNR-IGV), Palermo, Italy
| | - Cindy Ast
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
- NanoPolyPhotonik, Fraunhofer Institute for Applied Polymer Research, Potsdam-Golm, Germany
| | - Dominique Loqué
- Feedstocks Division, Joint BioEnergy Institute, Emeryville, United States
| | - Cheng-Hsun Ho
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Susana LA Andrade
- Department of Biochemistry, Institute for Organic Chemistry and Biochemistry, and BIOSS Center for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Viviane Lanquar
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Guido Grossmann
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
| | - Sören Gehne
- Department of Physical Chemistry, Institute of Chemistry, University of Potsdam, Potsdam, Germany
| | - Michael U Kumke
- Department of Physical Chemistry, Institute of Chemistry, University of Potsdam, Potsdam, Germany
| | - Wolf B Frommer
- Department of Plant Biology, Carnegie Institution for Science, Stanford, United States
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Kanda N, Abe F. Structural and functional implications of the yeast high-affinity tryptophan permease Tat2. Biochemistry 2013; 52:4296-307. [PMID: 23768406 DOI: 10.1021/bi4004638] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Tryptophan is hydrophobic, bulky, and the rarest amino acid found in nutrients. Accordingly, the import machinery can be specialized evolutionarily. Our previous study in Saccharomyces cerevisiae demonstrated that tryptophan import by the high-affinity tryptophan permease Tat2 is accompanied by a large volume increase during substrate import. Nevertheless, the mechanisms by which the permease mediates tryptophan recognition and permeation remain to be elucidated. Here we determined amino acid residues essential for Tat2-mediated tryptophan import. By means of random mutagenesis in combination with site-directed mutagenesis based on crystallographic studies of the Escherichia coli arginine/agmatine antiporter AdiC, we identified 15 amino acid residues in the Tat2 transmembrane domains (TMDs) 1, -3, -5, -8, and -10, which are responsible for tryptophan uptake. T98, Y167, and E286 were assumed to form the central cavity in Tat2. G97/T98 and E286 were located within the putative α-helix break in TMD1 and TMD6, respectively, which are highly conserved among yeast amino acid permeases and bacterial solute transporters. Given the conformational change in AdiC upon substrate binding, G97/T98 and E286 of Tat2 were assumed to mediate a structural shift from an outward-open to a tryptophan-bound-occluded structure upon tryptophan binding, and T320, V322, and F324 became stabilized in TMD7. Such dynamic structural changes may account for the large volume increase associated with tryptophan import occurring concomitantly with a movement of water molecules from the tryptophan binding site. We also propose the working hypothesis that E286 mediates the proton influx that is coupled to tryptophan import.
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Affiliation(s)
- Naoko Kanda
- Department of Chemistry and Biological Science, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan
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Møller HD, Andersen KS, Regenberg B. A model for generating several adaptive phenotypes from a single genetic event: Saccharomyces cerevisiae GAP1 as a potential bet-hedging switch. Commun Integr Biol 2013; 6:e23933. [PMID: 23713139 PMCID: PMC3656021 DOI: 10.4161/cib.23933] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 02/08/2013] [Indexed: 11/19/2022] Open
Abstract
Microbial populations adapt to environmental fluctuations through random switching of fitness-related traits in individual cells. This increases the likelihood that a subpopulation will be adaptive in a future milieu. However, populations are particularly challenged when several environment factors change simultaneously. We suggest that a population can rapidly adapt to multiple environmental changes if individual members stochastically flip a hub-switch that controls a set of adaptive phenotypes in a single event. This mechanism of coupling phenotypic outcomes via a hub-switch can protect a population against large fluctuations in size. Here we report that the general amino acid transporter Gap1 is a potential hub-switch. The GAP1 gene is flanked by two direct repeats that can lead to GAP1 deletions (∆gap1) and a self-replicating GAP1 circle. Thus, an isogenic GAP1 population can differentiate into two variant, reversible genotypes, ∆gap1 or GAP1 (circle). These subpopulations have different phenotypic advantages. A ∆gap1 population has a selective advantage on allantoin or ammonium as a nitrogen source and high stress tolerance. Advantages of the GAP1 population include amino acid uptake, fast energy recruitment by trehalose mobilization, and in some cases, adherent biofilm growth. Our proposed model of a hub-switch locus enhances the bet-hedging model of population dynamics.
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Affiliation(s)
- Henrik D Møller
- Molecular Integrative Physiology; University of Copenhagen; Copenhagen, Denmark
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Schepers W, Van Zeebroeck G, Pinkse M, Verhaert P, Thevelein JM. In vivo phosphorylation of Ser21 and Ser83 during nutrient-induced activation of the yeast protein kinase A (PKA) target trehalase. J Biol Chem 2012; 287:44130-42. [PMID: 23155055 PMCID: PMC3531729 DOI: 10.1074/jbc.m112.421503] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The readdition of an essential nutrient to starved, fermenting cells of the yeast Saccharomyces cerevisiae triggers rapid activation of the protein kinase A (PKA) pathway. Trehalase is activated 5–10-fold within minutes and has been used as a convenient reporter for rapid activation of PKA in vivo. Although trehalase can be phosphorylated and activated by PKA in vitro, demonstration of phosphorylation during nutrient activation in vivo has been lacking. We now show, using phosphospecific antibodies, that glucose and nitrogen activation of trehalase in vivo is associated with phosphorylation of Ser21 and Ser83. Unexpectedly, mutants with reduced PKA activity show constitutive phosphorylation despite reduced trehalase activation. The same phenotype was observed upon deletion of the catalytic subunits of yeast protein phosphatase 2A, suggesting that lower PKA activity causes reduced trehalase dephosphorylation. Hence, phosphorylation of trehalase in vivo is not sufficient for activation. Deletion of the inhibitor Dcs1 causes constitutive trehalase activation and phosphorylation. It also enhances binding of trehalase to the 14-3-3 proteins Bmh1 and Bmh2, suggesting that Dcs1 inhibits by preventing 14-3-3 binding. Deletion of Bmh1 and Bmh2 eliminates both trehalase activation and phosphorylation. Our results reveal that trehalase activation in vivo is associated with phosphorylation of typical PKA sites and thus establish the enzyme as a reliable read-out for nutrient activation of PKA in vivo.
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Affiliation(s)
- Wim Schepers
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
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