1
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Mishra S, Welch N, Singh SS, Singh KD, Bellar A, Kumar A, Deutz LN, Hanlon MD, Kant S, Dastidar S, Patel H, Agrawal V, Attaway AH, Musich R, Stark GR, Tedesco FS, Truskey GA, Weiner ID, Karnik SS, Dasarathy S. Ammonia transporter RhBG initiates downstream signaling and functional responses by activating NFκB. Proc Natl Acad Sci U S A 2024; 121:e2314760121. [PMID: 39052834 PMCID: PMC11294993 DOI: 10.1073/pnas.2314760121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2023] [Accepted: 06/19/2024] [Indexed: 07/27/2024] Open
Abstract
Transceptors, solute transporters that facilitate intracellular entry of molecules and also initiate intracellular signaling events, have been primarily studied in lower-order species. Ammonia, a cytotoxic endogenous metabolite, is converted to urea in hepatocytes for urinary excretion in mammals. During hyperammonemia, when hepatic metabolism is impaired, nonureagenic ammonia disposal occurs primarily in skeletal muscle. Increased ammonia uptake in skeletal muscle is mediated by a membrane-bound, 12 transmembrane domain solute transporter, Rhesus blood group-associated B glycoprotein (RhBG). We show that in addition to its transport function, RhBG interacts with myeloid differentiation primary response-88 (MyD88) to initiate an intracellular signaling cascade that culminates in activation of NFκB. We also show that ammonia-induced MyD88 signaling is independent of the canonical toll-like receptor-initiated mechanism of MyD88-dependent NFκB activation. In silico, in vitro, and in situ experiments show that the conserved cytosolic J-domain of the RhBG protein interacts with the Toll-interleukin-1 receptor (TIR) domain of MyD88. In skeletal muscle from human patients, human-induced pluripotent stem cell-derived myotubes, and myobundles show an interaction of RhBG-MyD88 during hyperammonemia. Using complementary experimental and multiomics analyses in murine myotubes and mice with muscle-specific RhBG or MyD88 deletion, we show that the RhBG-MyD88 interaction is essential for the activation of NFkB but not ammonia transport. Our studies show a paradigm of substrate-dependent regulation of transceptor function with the potential for modulation of cellular responses in mammalian systems by decoupling transport and signaling functions of transceptors.
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Affiliation(s)
- Saurabh Mishra
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Nicole Welch
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
- Gastroenterology and Hepatology, Lerner Research Institute, Cleveland, OH44195
| | - Shashi Shekhar Singh
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | | | - Annette Bellar
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Avinash Kumar
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Lars N. Deutz
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Maxmillian D. Hanlon
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Sashi Kant
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Sumitava Dastidar
- Department of Cell and Developmental Biology, University College London & The Francis Crick Institute, LondonWC1E6DE, UK
| | - Hailee Patel
- Duke Biomedical Engineering, Duke University, Durham, NC27708
| | - Vandana Agrawal
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - Amy H. Attaway
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
- Pulmonary Medicine, Lerner Research Institute, Cleveland, OH44195
| | - Ryan Musich
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
| | - George R. Stark
- Cancer Biology, Lerner Research Institute, Cleveland, OH44195
| | - Francesco Saverio Tedesco
- Department of Cell and Developmental Biology, University College London & The Francis Crick Institute, LondonWC1E6DE, UK
| | | | - I. David Weiner
- Division of Nephrology Hypertension, and Renal Transplantation, University of Florida, Gainesville, FL32610
- Nephrology and Hypertension Section, Gainesville, FL32610
| | - Sadashiva S. Karnik
- Cardiovascular and Metabolic Diseases, Lerner Research Institute, Cleveland, OH44195
| | - Srinivasan Dasarathy
- Department of Inflammation and Immunity, Lerner Research Institute, Cleveland, OH44195
- Gastroenterology and Hepatology, Lerner Research Institute, Cleveland, OH44195
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2
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Partipilo M, Jan Slotboom D. 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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3
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Kim JH, Mailloux L, Bloor D, Tae H, Nguyen H, McDowell M, Padilla J, DeWaard A. Multiple roles for the cytoplasmic C-terminal domains of the yeast cell surface receptors Rgt2 and Snf3 in glucose sensing and signaling. Sci Rep 2024; 14:4055. [PMID: 38374219 PMCID: PMC10876965 DOI: 10.1038/s41598-024-54628-2] [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: 01/11/2024] [Accepted: 02/14/2024] [Indexed: 02/21/2024] Open
Abstract
The plasma membrane proteins Rgt2 and Snf3 are glucose sensing receptors (GSRs) that generate an intracellular signal for the induction of gene expression in response to high and low extracellular glucose concentrations, respectively. The GSRs consist of a 12-transmembrane glucose recognition domain and a cytoplasmic C-terminal signaling tail. The GSR tails are dissimilar in length and sequence, but their distinct roles in glucose signal transduction are poorly understood. Here, we show that swapping the tails between Rgt2 and Snf3 does not alter the signaling activity of the GSRs, so long as their tails are phosphorylated in a Yck-dependent manner. Attachment of the GSR tails to Hxt1 converts the transporter into a glucose receptor; however, the tails attached to Hxt1 are not phosphorylated by the Ycks, resulting in only partial signaling. Moreover, in response to non-fermentable carbon substrates, Rgt2 and Hxt1-RT (RT, Rgt2-tail) are efficiently endocytosed, whereas Snf3 and Hxt1-ST (ST, Snf3-tail) are endocytosis-impaired. Thus, the tails are important regulatory domains required for the endocytosis of the Rgt2 and Snf3 glucose sensing receptors triggered by different cellular stimuli. Taken together, these results suggest multiple roles for the tail domains in GSR-mediated glucose sensing and signaling.
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Affiliation(s)
- Jeong-Ho Kim
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA.
| | - Levi Mailloux
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
| | - Daniel Bloor
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
| | - Haeun Tae
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
| | - Han Nguyen
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
| | - Morgan McDowell
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
| | - Jaqueline Padilla
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
| | - Anna DeWaard
- Department of Biology and Chemistry, Liberty University, 1971 University Blvd, Lynchburg, VA, 24502, USA
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4
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Palmgren M. P-type ATPases: Many more enigmas left to solve. J Biol Chem 2023; 299:105352. [PMID: 37838176 PMCID: PMC10654040 DOI: 10.1016/j.jbc.2023.105352] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Revised: 10/02/2023] [Accepted: 10/05/2023] [Indexed: 10/16/2023] Open
Abstract
P-type ATPases constitute a large ancient super-family of primary active pumps that have diverse substrate specificities ranging from H+ to phospholipids. The significance of these enzymes in biology cannot be overstated. They are structurally related, and their catalytic cycles alternate between high- and low-affinity conformations that are induced by phosphorylation and dephosphorylation of a conserved aspartate residue. In the year 1988, all P-type sequences available by then were analyzed and five major families, P1 to P5, were identified. Since then, a large body of knowledge has accumulated concerning the structure, function, and physiological roles of members of these families, but only one additional family, P6 ATPases, has been identified. However, much is still left to be learned. For each family a few remaining enigmas are presented, with the intention that they will stimulate interest in continued research in the field. The review is by no way comprehensive and merely presents personal views with a focus on evolution.
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Affiliation(s)
- Michael Palmgren
- Department of Plant and Environmental Sciences, University of Copenhagen, Frederiksberg C, Denmark.
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5
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Dallatana A, Cremonesi L, Trombetta M, Fracasso G, Nocini R, Giacomello L, Innamorati G. G Protein-Coupled Receptors and the Rise of Type 2 Diabetes in Children. Biomedicines 2023; 11:1576. [PMID: 37371671 DOI: 10.3390/biomedicines11061576] [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: 05/11/2023] [Revised: 05/26/2023] [Accepted: 05/27/2023] [Indexed: 06/29/2023] Open
Abstract
The human genome counts hundreds of GPCRs specialized to sense thousands of different extracellular cues, including light, odorants and nutrients in addition to hormones. Primordial GPCRs were likely glucose transporters that became sensors to monitor the abundance of nutrients and direct the cell to switch from aerobic metabolism to fermentation. Human β cells express multiple GPCRs that contribute to regulate glucose homeostasis, cooperating with many others expressed by a variety of cell types and tissues. These GPCRs are intensely studied as pharmacological targets to treat type 2 diabetes in adults. The dramatic rise of type 2 diabetes incidence in pediatric age is likely correlated to the rapidly evolving lifestyle of children and adolescents of the new century. Current pharmacological treatments are based on therapies designed for adults, while youth and puberty are characterized by a different hormonal balance related to glucose metabolism. This review focuses on GPCRs functional traits that are relevant for β cells function, with an emphasis on aspects that could help to differentiate new treatments specifically addressed to young type 2 diabetes patients.
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Affiliation(s)
- Alessia Dallatana
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, 37134 Verona, Italy
| | - Linda Cremonesi
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, 37134 Verona, Italy
| | - Maddalena Trombetta
- Section of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Verona, 37124 Verona, Italy
| | - Giulio Fracasso
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - Riccardo Nocini
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, 37134 Verona, Italy
| | - Luca Giacomello
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, 37134 Verona, Italy
| | - Giulio Innamorati
- Department of Surgical Sciences, Dentistry, Gynecology and Pediatrics, University of Verona, 37134 Verona, Italy
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6
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Paulussen F, Kulkarni CP, Stolz F, Lescrinier E, De Graeve S, Lambin S, Marchand A, Chaltin P, In't Veld P, Mebis J, Tavernier J, Van Dijck P, Luyten W, Thevelein JM. The β2-adrenergic receptor in the apical membrane of intestinal enterocytes senses sugars to stimulate glucose uptake from the gut. Front Cell Dev Biol 2023; 10:1041930. [PMID: 36699012 PMCID: PMC9869975 DOI: 10.3389/fcell.2022.1041930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Accepted: 12/14/2022] [Indexed: 01/12/2023] Open
Abstract
The presence of sugar in the gut causes induction of SGLT1, the sodium/glucose cotransporter in intestinal epithelial cells (enterocytes), and this is accompanied by stimulation of sugar absorption. Sugar sensing was suggested to involve a G-protein coupled receptor and cAMP - protein kinase A signalling, but the sugar receptor has remained unknown. We show strong expression and co-localization with SGLT1 of the β2-adrenergic receptor (β 2-AR) at the enterocyte apical membrane and reveal its role in stimulating glucose uptake from the gut by the sodium/glucose-linked transporter, SGLT1. Upon heterologous expression in different reporter systems, the β 2-AR responds to multiple sugars in the mM range, consistent with estimated gut sugar levels after a meal. Most adrenergic receptor antagonists inhibit sugar signaling, while some differentially inhibit epinephrine and sugar responses. However, sugars did not inhibit binding of I125-cyanopindolol, a β 2-AR antagonist, to the ligand-binding site in cell-free membrane preparations. This suggests different but interdependent binding sites. Glucose uptake into everted sacs from rat intestine was stimulated by epinephrine and sugars in a β 2-AR-dependent manner. STD-NMR confirmed direct physical binding of glucose to the β 2-AR. Oral administration of glucose with a non-bioavailable β 2-AR antagonist lowered the subsequent increase in blood glucose levels, confirming a role for enterocyte apical β 2-ARs in stimulating gut glucose uptake, and suggesting enterocyte β 2-AR as novel drug target in diabetic and obese patients. Future work will have to reveal how glucose sensing by enterocytes and neuroendocrine cells is connected, and whether β 2-ARs mediate glucose sensing also in other tissues.
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Affiliation(s)
- Frederik Paulussen
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Chetan P. Kulkarni
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,3Functional Genomics and Proteomics Research Unit, Department of Biology, KU Leuven, Leuven, Belgium
| | - Frank Stolz
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Eveline Lescrinier
- 4Medicinal Chemistry, Rega Institute for Medical Research, KU Leuven, Leuven, Belgium
| | - Stijn De Graeve
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Suzan Lambin
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | | | | | - Peter In't Veld
- 6Department of Pathology, Free University of Brussels, Brussels, Belgium
| | - Joseph Mebis
- 7Department of Pathology, KU Leuven, Flanders, Belgium
| | - Jan Tavernier
- 8Department of Biochemistry, Faculty of Medicine and Health Sciences, Ghent University, Ghent, Belgium,9Center for Medical Biotechnology, VIB, Ghent, Belgium
| | - Patrick Van Dijck
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium
| | - Walter Luyten
- 3Functional Genomics and Proteomics Research Unit, Department of Biology, KU Leuven, Leuven, Belgium
| | - Johan M. Thevelein
- 1Center for Microbiology, VIB, Leuven-Heverlee, Belgium,2Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Leuven-Heverlee, Belgium,10NovelYeast bv, Bio-Incubator BIO4, Gaston Geenslaan 3, Leuven-Heverlee,, Belgium,*Correspondence: Johan M. Thevelein,
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7
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Dreyer I, Li K, Riedelsberger J, Hedrich R, Konrad KR, Michard E. Transporter networks can serve plant cells as nutrient sensors and mimic transceptor-like behavior. iScience 2022; 25:104078. [PMID: 35378857 PMCID: PMC8976136 DOI: 10.1016/j.isci.2022.104078] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 02/03/2022] [Accepted: 03/11/2022] [Indexed: 12/25/2022] Open
Abstract
Sensing of external mineral nutrient concentrations is essential for plants to colonize environments with a large spectrum of nutrient availability. Here, we analyzed transporter networks in computational cell biology simulations to understand better the initial steps of this sensing process. The networks analyzed were capable of translating the information of changing external nutrient concentrations into cytosolic H+ and Ca2+ signals, two of the most ubiquitous cellular second messengers. The concept emerging from the computational simulations was confirmed in wet-lab experiments. We document in guard cells that alterations in the external KCl concentration were translated into cytosolic H+ and Ca2+ transients as predicted. We show that transporter networks do not only serve their primary task of transport, but can also take on the role of a receptor without requiring conformational changes of a transporter protein. Such transceptor-like phenomena may be quite common in plants.
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Affiliation(s)
- Ingo Dreyer
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Talca, Avenida Lircay, Talca 3460000, Chile
| | - Kunkun Li
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, Julius-von-Sachs-Platz 2, 97082 Wuerzburg, Germany
| | - Janin Riedelsberger
- Centro de Bioinformática, Simulación y Modelado (CBSM), Facultad de Ingeniería, Universidad de Talca, Campus Talca, Avenida Lircay, Talca 3460000, Chile
| | - Rainer Hedrich
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, Julius-von-Sachs-Platz 2, 97082 Wuerzburg, Germany
| | - Kai R. Konrad
- Department of Botany I, Julius-Von-Sachs Institute for Biosciences, University of Wuerzburg, Julius-von-Sachs-Platz 2, 97082 Wuerzburg, Germany
| | - Erwan Michard
- Instituto de Ciencias Biológicas, Universidad de Talca, Campus Talca, Avenida Lircay, Talca 3460000, Chile
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Monteagudo-Cascales E, Santero E, Canosa I. The Regulatory Hierarchy Following Signal Integration by the CbrAB Two-Component System: Diversity of Responses and Functions. Genes (Basel) 2022; 13:genes13020375. [PMID: 35205417 PMCID: PMC8871633 DOI: 10.3390/genes13020375] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 02/14/2022] [Accepted: 02/16/2022] [Indexed: 02/04/2023] Open
Abstract
CbrAB is a two-component system, unique to bacteria of the family Pseudomonaceae, capable of integrating signals and involved in a multitude of physiological processes that allow bacterial adaptation to a wide variety of varying environmental conditions. This regulatory system provides a great metabolic versatility that results in excellent adaptability and metabolic optimization. The two-component system (TCS) CbrA-CbrB is on top of a hierarchical regulatory cascade and interacts with other regulatory systems at different levels, resulting in a robust output. Among the regulatory systems found at the same or lower levels of CbrAB are the NtrBC nitrogen availability adaptation system, the Crc/Hfq carbon catabolite repression cascade in Pseudomonas, or interactions with the GacSA TCS or alternative sigma ECF factor, such as SigX. The interplay between regulatory mechanisms controls a number of physiological processes that intervene in important aspects of bacterial adaptation and survival. These include the hierarchy in the use of carbon sources, virulence or resistance to antibiotics, stress response or definition of the bacterial lifestyle. The multiple actions of the CbrAB TCS result in an important competitive advantage.
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Affiliation(s)
| | - Eduardo Santero
- Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Centro Andaluz de Biología del Desarrollo, CSIC, Junta de Andalucía, 41013 Seville, Spain;
| | - Inés Canosa
- Departamento de Biología Molecular e Ingeniería Bioquímica, Universidad Pablo de Olavide, Centro Andaluz de Biología del Desarrollo, CSIC, Junta de Andalucía, 41013 Seville, Spain;
- Correspondence: ; Tel.: +34-954349052
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9
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Breia R, Conde A, Badim H, Fortes AM, Gerós H, Granell A. Plant SWEETs: from sugar transport to plant-pathogen interaction and more unexpected physiological roles. PLANT PHYSIOLOGY 2021; 186:836-852. [PMID: 33724398 PMCID: PMC8195505 DOI: 10.1093/plphys/kiab127] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/05/2021] [Indexed: 05/19/2023]
Abstract
Sugars Will Eventually be Exported Transporters (SWEETs) have important roles in numerous physiological mechanisms where sugar efflux is critical, including phloem loading, nectar secretion, seed nutrient filling, among other less expected functions. They mediate low affinity and high capacity transport, and in angiosperms this family is composed by 20 paralogs on average. As SWEETs facilitate the efflux of sugars, they are highly susceptible to hijacking by pathogens, making them central players in plant-pathogen interaction. For instance, several species from the Xanthomonas genus are able to upregulate the transcription of SWEET transporters in rice (Oryza sativa), upon the secretion of transcription-activator-like effectors. Other pathogens, such as Botrytis cinerea or Erysiphe necator, are also capable of increasing SWEET expression. However, the opposite behavior has been observed in some cases, as overexpression of the tonoplast AtSWEET2 during Pythium irregulare infection restricted sugar availability to the pathogen, rendering plants more resistant. Therefore, a clear-cut role for SWEET transporters during plant-pathogen interactions has so far been difficult to define, as the metabolic signatures and their regulatory nodes, which decide the susceptibility or resistance responses, remain poorly understood. This fuels the still ongoing scientific question: what roles can SWEETs play during plant-pathogen interaction? Likewise, the roles of SWEET transporters in response to abiotic stresses are little understood. Here, in addition to their relevance in biotic stress, we also provide a small glimpse of SWEETs importance during plant abiotic stress, and briefly debate their importance in the particular case of grapevine (Vitis vinifera) due to its socioeconomic impact.
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Affiliation(s)
- Richard Breia
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro, Vila Real 5001-801, Portugal
| | - Artur Conde
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro, Vila Real 5001-801, Portugal
- Author for communication:
| | - Hélder Badim
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
| | - Ana Margarida Fortes
- Lisbon Science Faculty, BioISI, University of Lisbon, Campo Grande, Lisbon 1749-016, Portugal
| | - Hernâni Gerós
- Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, Braga 4710-057, Portugal
- Centre for the Research and Technology of Agro-Environmental and Biological Sciences (CITAB), University of Trás-os-Montes e Alto Douro, Vila Real 5001-801, Portugal
- Centre of Biological Engineering (CEB), Department of Engineering, University of Minho, Braga 4710-057, Portugal
| | - Antonio Granell
- Institute of Molecular and Cellular Biology of Plants, Spanish National Research Council (CSIC), Polytechnic University of Valencia, Valencia 46022, Spain
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10
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Johns LE, Goldman GH, Ries LN, Brown NA. Nutrient sensing and acquisition in fungi: mechanisms promoting pathogenesis in plant and human hosts. FUNGAL BIOL REV 2021. [DOI: 10.1016/j.fbr.2021.01.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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11
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Drew D, North RA, Nagarathinam K, Tanabe M. Structures and General Transport Mechanisms by the Major Facilitator Superfamily (MFS). Chem Rev 2021; 121:5289-5335. [PMID: 33886296 PMCID: PMC8154325 DOI: 10.1021/acs.chemrev.0c00983] [Citation(s) in RCA: 165] [Impact Index Per Article: 55.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Indexed: 12/12/2022]
Abstract
The major facilitator superfamily (MFS) is the largest known superfamily of secondary active transporters. MFS transporters are responsible for transporting a broad spectrum of substrates, either down their concentration gradient or uphill using the energy stored in the electrochemical gradients. Over the last 10 years, more than a hundred different MFS transporter structures covering close to 40 members have provided an atomic framework for piecing together the molecular basis of their transport cycles. Here, we summarize the remarkable promiscuity of MFS members in terms of substrate recognition and proton coupling as well as the intricate gating mechanisms undergone in achieving substrate translocation. We outline studies that show how residues far from the substrate binding site can be just as important for fine-tuning substrate recognition and specificity as those residues directly coordinating the substrate, and how a number of MFS transporters have evolved to form unique complexes with chaperone and signaling functions. Through a deeper mechanistic description of glucose (GLUT) transporters and multidrug resistance (MDR) antiporters, we outline novel refinements to the rocker-switch alternating-access model, such as a latch mechanism for proton-coupled monosaccharide transport. We emphasize that a full understanding of transport requires an elucidation of MFS transporter dynamics, energy landscapes, and the determination of how rate transitions are modulated by lipids.
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Affiliation(s)
- David Drew
- Department
of Biochemistry and Biophysics, Stockholm
University, SE 106 91 Stockholm, Sweden
| | - Rachel A. North
- Department
of Biochemistry and Biophysics, Stockholm
University, SE 106 91 Stockholm, Sweden
| | - Kumar Nagarathinam
- Center
of Structural and Cell Biology in Medicine, Institute of Biochemistry, University of Lübeck, D-23538, Lübeck, Germany
| | - Mikio Tanabe
- Structural
Biology Research Center, Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan
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12
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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: 2.3] [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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13
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Van Zeebroeck G, Demuyser L, Zhang Z, Cottignie I, Thevelein JM. Nutrient sensing and cAMP signaling in yeast: G-protein coupled receptor versus transceptor activation of PKA. MICROBIAL CELL (GRAZ, AUSTRIA) 2020; 8:17-27. [PMID: 33490229 PMCID: PMC7780724 DOI: 10.15698/mic2021.01.740] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 09/12/2020] [Accepted: 09/17/2020] [Indexed: 11/13/2022]
Abstract
A major signal transduction pathway regulating cell growth and many associated physiological properties as a function of nutrient availability in the yeast Saccharomyces cerevisiae is the protein kinase A (PKA) pathway. Glucose activation of PKA is mediated by G-protein coupled receptor (GPCR) Gpr1, and secondary messenger cAMP. Other nutrients, including nitrogen, phosphate and sulfate, activate PKA in accordingly-starved cells through nutrient transceptors, but apparently without cAMP signaling. We have now used an optimized EPAC-based fluorescence resonance energy transfer (FRET) sensor to precisely monitor in vivo cAMP levels after nutrient addition. We show that GPCR-mediated glucose activation of PKA is correlated with a rapid transient increase in the cAMP level in vivo, whereas nutrient transceptor-mediated activation by nitrogen, phosphate or sulfate, is not associated with any significant increase in cAMP in vivo. We also demonstrate direct physical interaction between the Gap1 amino acid transceptor and the catalytic subunits of PKA, Tpk1, 2 and 3. In addition, we reveal a conserved consensus motif in the nutrient transceptors that is also present in Bcy1, the regulatory subunit of PKA. This suggests that nutrient transceptor activation of PKA may be mediated by direct release of bound PKA catalytic subunits, triggered by the conformational changes occurring during transport of the substrate by the transceptor. Our results support a model in which nutrient transceptors are evolutionary ancestors of GPCRs, employing a more primitive direct signaling mechanism compared to the indirect cAMP second-messenger signaling mechanism used by GPCRs for activation of PKA.
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Affiliation(s)
- Griet Van Zeebroeck
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
- These authors made an equal contribution to this work
| | - Liesbeth Demuyser
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
- These authors made an equal contribution to this work
| | - Zhiqiang Zhang
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, B-3001 Leuven-Heverlee, Flanders, 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, B-3001 Leuven-Heverlee, Flanders, 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, B-3001 Leuven-Heverlee, Flanders, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
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14
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Mechanisms for Induction of Microbial Extracellular Proteases in Response to Exterior Proteins. Appl Environ Microbiol 2020; 86:AEM.01036-20. [PMID: 32709731 DOI: 10.1128/aem.01036-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Proteins are a main organic nitrogen source for microorganisms. Many heterotrophic microorganisms secrete extracellular proteases (ex-proteases) to efficiently decompose proteins into oligopeptides and amino acids when exterior proteins are required for growth. These ex-proteases not only play important roles in microbial nutrient acquisition or host infection but also contribute greatly to the global recycling of carbon and nitrogen. Moreover, may microbial ex-proteases have important applications in industrial, medical, and biotechnological areas. Therefore, uncovering the mechanisms by which microorganisms initiate the expression of ex-protease genes in response to exterior proteins is of great significance. In this review, the progress made in understanding the induction mechanisms of microbial ex-proteases in response to exterior proteins is summarized, with a focus on the inducer molecules, membrane sensors, and downstream pathways. Problems to be solved for better understanding of the induction mechanisms of microbial ex-proteases are also discussed.
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15
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Amick J, Tharkeshwar AK, Talaia G, Ferguson SM. PQLC2 recruits the C9orf72 complex to lysosomes in response to cationic amino acid starvation. J Cell Biol 2020; 219:132798. [PMID: 31851326 PMCID: PMC7039192 DOI: 10.1083/jcb.201906076] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Revised: 10/07/2019] [Accepted: 10/25/2019] [Indexed: 12/13/2022] Open
Abstract
This study reveals that PQLC2, a lysosomal transporter of cationic amino acids, coordinates cellular responses to cationic amino acid availability via the regulated recruitment of a heterotrimeric protein complex containing C9orf72, SMCR8, and WDR41 to the surface of lysosomes. The C9orf72 protein is required for normal lysosome function. In support of such functions, C9orf72 forms a heterotrimeric complex with SMCR8 and WDR41 that is recruited to lysosomes when amino acids are scarce. These properties raise questions about the identity of the lysosomal binding partner of the C9orf72 complex and the amino acid–sensing mechanism that regulates C9orf72 complex abundance on lysosomes. We now demonstrate that an interaction with the lysosomal cationic amino acid transporter PQLC2 mediates C9orf72 complex recruitment to lysosomes. This is achieved through an interaction between PQLC2 and WDR41. The interaction between PQLC2 and the C9orf72 complex is negatively regulated by arginine, lysine, and histidine, the amino acids that PQLC2 transports across the membrane of lysosomes. These results define a new role for PQLC2 in the regulated recruitment of the C9orf72 complex to lysosomes and reveal a novel mechanism that allows cells to sense and respond to changes in the availability of cationic amino acids within lysosomes.
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Affiliation(s)
- Joseph Amick
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Arun Kumar Tharkeshwar
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Gabriel Talaia
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
| | - Shawn M Ferguson
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT.,Department of Neuroscience, Yale University School of Medicine, New Haven, CT.,Program in Cellular Neuroscience, Neurodegeneration and Repair, Yale University School of Medicine, New Haven, CT
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16
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Touching the Surface: Diverse Roles for the Flagellar Membrane in Kinetoplastid Parasites. Microbiol Mol Biol Rev 2020; 84:84/2/e00079-19. [PMID: 32238446 DOI: 10.1128/mmbr.00079-19] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
While flagella have been studied extensively as motility organelles, with a focus on internal structures such as the axoneme, more recent research has illuminated the roles of the flagellar surface in a variety of biological processes. Parasitic protists of the order Kinetoplastida, which include trypanosomes and Leishmania species, provide a paradigm for probing the role of flagella in host-microbe interactions and illustrate that this interface between the flagellar surface and the host is of paramount importance. An increasing body of knowledge indicates that the flagellar membrane serves a multitude of functions at this interface: attachment of parasites to tissues within insect vectors, close interactions with intracellular organelles of vertebrate cells, transactions between flagella from different parasites, junctions between the flagella and the parasite cell body, emergence of nanotubes and exosomes from the parasite directed to either host or microbial targets, immune evasion, and sensing of the extracellular milieu. Recent whole-organelle or genome-wide studies have begun to identify protein components of the flagellar surface that must mediate these diverse host-parasite interactions. The increasing corpus of knowledge on kinetoplastid flagella will likely prove illuminating for other flagellated or ciliated pathogens as well.
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17
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Quantifying secondary transport at single-molecule resolution. Nature 2019; 575:528-534. [PMID: 31723269 DOI: 10.1038/s41586-019-1747-5] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2019] [Accepted: 10/07/2019] [Indexed: 01/07/2023]
Abstract
Secondary active transporters, which are vital for a multitude of physiological processes, use the energy of electrochemical ion gradients to power substrate transport across cell membranes1,2. Efforts to investigate their mechanisms of action have been hampered by their slow transport rates and the inherent limitations of ensemble methods. Here we quantify the activity of individual MhsT transporters, which are representative of the neurotransmitter:sodium symporter family of secondary transporters3, by imaging the transport of individual substrate molecules across lipid bilayers at both single- and multi-turnover resolution. We show that MhsT is active only when physiologically oriented and that the rate-limiting step of the transport cycle varies with the nature of the transported substrate. These findings are consistent with an extracellular allosteric substrate-binding site that modulates the rate-limiting aspects of the transport mechanism4,5, including the rate at which the transporter returns to an outward-facing state after the transported substrate is released.
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18
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Affiliation(s)
- Bert van den Berg
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Siobhan Lister
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Julian C. Rutherford
- Institute for Cell and Molecular Biosciences, Medical School, Newcastle University, Newcastle upon Tyne, United Kingdom
- * E-mail:
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19
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Gomi K. Regulatory mechanisms for amylolytic gene expression in the koji mold Aspergillus oryzae. Biosci Biotechnol Biochem 2019; 83:1385-1401. [PMID: 31159661 DOI: 10.1080/09168451.2019.1625265] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The koji mold Aspergillus oryzae has been used in traditional Japanese food and beverage fermentation for over a thousand years. Amylolytic enzymes are important in sake fermentation, wherein production is induced by starch or malto-oligosaccharides. This inducible production requires at least two transcription activators, AmyR and MalR. Among amylolytic enzymes, glucoamylase GlaB is produced exclusively in solid-state culture and plays a critical role in sake fermentation owing to its contribution to glucose generation from starch. A recent study demonstrated that glaB gene expression is regulated by a novel transcription factor, FlbC, in addition to AmyR in solid-state culture. Amylolytic enzyme production is generally repressed by glucose due to carbon catabolite repression (CCR), which is mediated by the transcription factor CreA. Modifying CCR machinery, including CreA, can improve amylolytic enzyme production. This review focuses on the role of transcription factors in regulating A. oryzae amylolytic gene expression.
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Affiliation(s)
- Katsuya Gomi
- a Laboratory of Fermentation Microbiology, Graduate School of Agricultural Science , Tohoku University , Sendai , Japan
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20
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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: 29] [Impact Index Per Article: 5.8] [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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21
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Landfear SM, Zilberstein D. Sensing What's Out There - Kinetoplastid Parasites. Trends Parasitol 2019; 35:274-277. [PMID: 30655057 DOI: 10.1016/j.pt.2018.12.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2018] [Revised: 12/20/2018] [Accepted: 12/21/2018] [Indexed: 12/12/2022]
Abstract
Kinetoplastid parasites such as trypanosomes and Leishmania must adapt to their environments to survive within their hosts, yet they do not express many of the well established families of signal transduction receptors. Evidence suggests that other membrane proteins, including transporters and channels, play central roles in environmental sensing in these parasites.
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Affiliation(s)
- Scott M Landfear
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA.
| | - Dan Zilberstein
- Faculty of Biology, Technion-Israel Institute of Technology, Haifa, Israel
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22
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Landfear SM. Protean permeases: Diverse roles for membrane transport proteins in kinetoplastid protozoa. Mol Biochem Parasitol 2018; 227:39-46. [PMID: 30590069 DOI: 10.1016/j.molbiopara.2018.12.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 12/13/2018] [Accepted: 12/19/2018] [Indexed: 11/26/2022]
Abstract
Kinetoplastid parasites such as Trypanosoma brucei, Trypanosoma cruzi, and Leishmania species rely upon their insect and vertebrate hosts to provide a plethora of nutrients throughout their life cycles. Nutrients and ions critical for parasite survival are taken up across the parasite plasma membrane by transporters and channels, polytopic membrane proteins that provide substrate-specific pores across the hydrophobic barrier. However, transporters and channels serve a wide range of biological functions beyond uptake of nutrients. This article highlights the diversity of activities that these integral membrane proteins serve and underscores the emerging complexity of their functions.
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Affiliation(s)
- Scott M Landfear
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, 97239, USA.
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23
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Stasyk OG, Denega IO, Padhorny D, Dmytruk KV, Kozakov D, Abbas C, Stasyk OV. Glucose regulation in the methylotrophic yeast Hansenula (Ogataea) polymorpha is mediated by a putative transceptor Gcr1. Int J Biochem Cell Biol 2018; 103:25-34. [PMID: 30081098 DOI: 10.1016/j.biocel.2018.08.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2018] [Revised: 07/31/2018] [Accepted: 08/02/2018] [Indexed: 12/26/2022]
Abstract
The HpGcr1, a hexose transporter homologue from the methylotrophic yeast Hansenula (Ogataea) polymorpha, was previously identified as being involved in glucose repression. Intriguingly, potential HpGcr1 orthologues are found only in the genomes of a few yeasts phylogenetically closely related to H. polymorpha, but are absent in all other yeasts. The other closest HpGcr1 homologues are fungal high-affinity glucose symporters or putative transceptors suggesting a possible HpGcr1 origin due to a specific archaic gene retention or via horizontal gene transfer from Eurotiales fungi. Herein we report that, similarly to other yeast non-transporting glucose sensors, the substitution of the conserved arginine residue converts HpGcr1R165K into a constitutively signaling form. Synthesis of HpGcr1R165K in gcr1Δ did not restore glucose transport or repression but instead profoundly impaired growth independent of carbon source used. Simultaneously, gcr1Δ was impaired in transcriptional induction of repressible peroxisomal alcohol oxidase and in growth on methanol. Overexpression of the functional transporter HpHxt1 in gcr1Δ partially restored growth on glucose and glucose repression but did not rescue impaired growth on methanol. Heterologous expression of HpGcr1 in a Saccharomyces cerevisiae hxt-null strain did not restore glucose uptake due to protein mislocalization. However, HpGcr1 overexpression in H. polymorpha led to increased sensitivity to extracellular 2-deoxyglucose, suggesting HpGcr1 is a functional glucose carrier. The combined data suggest that HpGcr1 represents a novel type of yeast glucose transceptor functioning also in the absence of glucose.
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Affiliation(s)
- Olena G Stasyk
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv, Ukraine; Department of Biochemistry, Ivan Franko National University of Lviv, Lviv, Ukraine
| | - Iryna O Denega
- Department of Biochemistry, Ivan Franko National University of Lviv, Lviv, Ukraine
| | - Dzmitry Padhorny
- Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Kostyantyn V Dmytruk
- Department of Molecular Genetics and Biotechnology, Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv, Ukraine
| | - Dima Kozakov
- Department of Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York, USA
| | | | - Oleh V Stasyk
- Department of Cell Signaling, Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv, Ukraine.
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24
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Genetic Analysis of Signal Generation by the Rgt2 Glucose Sensor of Saccharomyces cerevisiae. G3-GENES GENOMES GENETICS 2018; 8:2685-2696. [PMID: 29954842 PMCID: PMC6071613 DOI: 10.1534/g3.118.200338] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The yeast S. cerevisiae senses glucose through Snf3 and Rgt2, transmembrane proteins that generate an intracellular signal in response to glucose that leads to inhibition of the Rgt1 transcriptional repressor and consequently to derepression of HXT genes encoding glucose transporters. Snf3 and Rgt2 are thought to be glucose receptors because they are similar to glucose transporters. In contrast to glucose transporters, they have unusually long C-terminal tails that bind to Mth1 and Std1, paralogous proteins that regulate function of the Rgt1 transcription factor. We show that the C-terminal tail of Rgt2 is not responsible for its inability to transport glucose. To gain insight into how the glucose sensors generate an intracellular signal, we identified RGT2 mutations that cause constitutive signal generation. Most of the mutations alter evolutionarily-conserved amino acids in the transmembrane spanning regions of Rgt2 that are predicted to be involved in maintaining an outward-facing conformation or to be in the substrate binding site. Our analysis of these mutations suggests they cause Rgt2 to adopt inward-facing or occluded conformations that generate the glucose signal. These results support the idea that Rgt2 and Snf3 are glucose receptors that signal in response to binding of extracellular glucose and inform the basis of their signaling.
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25
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Fan SJ, Goberdhan DCI. PATs and SNATs: Amino Acid Sensors in Disguise. Front Pharmacol 2018; 9:640. [PMID: 29971004 PMCID: PMC6018406 DOI: 10.3389/fphar.2018.00640] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Accepted: 05/29/2018] [Indexed: 11/30/2022] Open
Abstract
Solute Carriers (SLCs) are involved in the transport of substances across lipid bilayers, including nutrients like amino acids. Amino acids increase the activity of the microenvironmental sensor mechanistic Target of Rapamycin Complex 1 (mTORC1) to promote cellular growth and anabolic processes. They can be brought in to cells by a wide range of SLCs including the closely related Proton-assisted Amino acid Transporter (PAT or SLC36) and Sodium-coupled Neutral Amino acid Transporter (SNAT or SLC38) families. More than a decade ago, the first evidence emerged that members of the PAT family can act as amino acid-stimulated receptors, or so-called "transceptors," connecting amino acids to mTORC1 activation. Since then, further studies in human cell models have suggested that other PAT and SNAT family members, which share significant homology within their transmembrane domains, can act as transceptors. A paradigm shift has also led to the PATs and SNATs at the surface of multiple intracellular compartments being linked to the recruitment and activation of different pools of mTORC1. Much focus has been on late endosomes and lysosomes as mTORC1 regulatory hubs, but more recently a Golgi-localized PAT was shown to be required for mTORC1 activation. PATs and SNATs can also traffic between the cell surface and intracellular compartments, with regulation of this movement providing a means of controlling their mTORC1 regulatory activity. These emerging features of PAT and SNAT amino acid sensors, including the transceptor mechanism, have implications for the pharmacological inhibition of mTORC1 and new therapeutic interventions.
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Affiliation(s)
| | - Deborah C. I. Goberdhan
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
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26
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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: 26] [Impact Index Per Article: 4.3] [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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27
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Bezrutczyk M, Yang J, Eom JS, Prior M, Sosso D, Hartwig T, Szurek B, Oliva R, Vera-Cruz C, White FF, Yang B, Frommer WB. Sugar flux and signaling in plant-microbe interactions. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2018; 93:675-685. [PMID: 29160592 DOI: 10.1111/tpj.13775] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/29/2017] [Accepted: 11/01/2017] [Indexed: 05/04/2023]
Abstract
Plant breeders have developed crop plants that are resistant to pests, but the continual evolution of pathogens creates the need to iteratively develop new control strategies. Molecular tools have allowed us to gain deep insights into disease responses, allowing for more efficient, rational engineering of crops that are more robust or resistant to a greater number of pathogen variants. Here we describe the roles of SWEET and STP transporters, membrane proteins that mediate transport of sugars across the plasma membrane. We discuss how these transporters may enhance or restrict disease through controlling the level of nutrients provided to pathogens and whether the transporters play a role in sugar signaling for disease resistance. This review indicates open questions that require further research and proposes the use of genome editing technologies for engineering disease resistance.
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Affiliation(s)
- Margaret Bezrutczyk
- Institute for Molecular Physiology, Heinrich Heine Universität Düsseldorf, Universiätsstr. 1, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829, Köln, Germany
| | - Jungil Yang
- Institute for Molecular Physiology, Heinrich Heine Universität Düsseldorf, Universiätsstr. 1, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829, Köln, Germany
| | - Joon-Seob Eom
- Institute for Molecular Physiology, Heinrich Heine Universität Düsseldorf, Universiätsstr. 1, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829, Köln, Germany
| | - Matthew Prior
- Center for Plant Cell Biology and Department of Botany and Plant Sciences, University of California, 900 University Ave., Riverside, CA, 92521, USA
| | - Davide Sosso
- Inari Agriculture Inc., 200 Sidney Street, Cambridge, MA, 02139, USA
| | - Thomas Hartwig
- Institute for Molecular Physiology, Heinrich Heine Universität Düsseldorf, Universiätsstr. 1, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829, Köln, Germany
| | - Boris Szurek
- IRD, Cirad, University of Montpellier, BP 64501, 911 Avenue Agropolis, 34394, Montpellier Cedex 5, France
| | - Ricardo Oliva
- International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
| | - Casiana Vera-Cruz
- International Rice Research Institute, DAPO Box 7777, Metro Manila, Philippines
| | - Frank F White
- Department of Plant Pathology, University of Florida, 1449 Fifield Hall, 2550 Hull Road, PO Box 110680, Gainesville, FL, 32611, USA
| | - Bing Yang
- Department of Genetics, Development, and Cell Biology, Iowa State University, Ames, IA, 50011, USA
| | - Wolf B Frommer
- Institute for Molecular Physiology, Heinrich Heine Universität Düsseldorf, Universiätsstr. 1, 40225, Düsseldorf, Germany
- Max Planck Institute for Plant Breeding Research, Carl von Linné Weg 10, 50829, Köln, Germany
- Institute for Transformative Biomolecules (ITbM), Nagoya University, JapanITbM Building 6F, Furo, Chikusa, Nagoya, 464-8602, Japan
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28
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Bon N, Couasnay G, Bourgine A, Sourice S, Beck-Cormier S, Guicheux J, Beck L. Phosphate (P i)-regulated heterodimerization of the high-affinity sodium-dependent P i transporters PiT1/Slc20a1 and PiT2/Slc20a2 underlies extracellular P i sensing independently of P i uptake. J Biol Chem 2017; 293:2102-2114. [PMID: 29233890 DOI: 10.1074/jbc.m117.807339] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Revised: 11/16/2017] [Indexed: 12/24/2022] Open
Abstract
Extracellular phosphate (Pi) can act as a signaling molecule that directly alters gene expression and cellular physiology. The ability of cells or organisms to detect changes in extracellular Pi levels implies the existence of a Pi-sensing mechanism that signals to the body or individual cell. However, unlike in prokaryotes, yeasts, and plants, the molecular players involved in Pi sensing in mammals remain unknown. In this study, we investigated the involvement of the high-affinity, sodium-dependent Pi transporters PiT1 and PiT2 in mediating Pi signaling in skeletal cells. We found that deletion of PiT1 or PiT2 blunted the Pi-dependent ERK1/2-mediated phosphorylation and subsequent gene up-regulation of the mineralization inhibitors matrix Gla protein and osteopontin. This result suggested that both PiTs are necessary for Pi signaling. Moreover, the ERK1/2 phosphorylation could be rescued by overexpressing Pi transport-deficient PiT mutants. Using cross-linking and bioluminescence resonance energy transfer approaches, we found that PiT1 and PiT2 form high-abundance homodimers and Pi-regulated low-abundance heterodimers. Interestingly, in the absence of sodium-dependent Pi transport activity, the PiT1-PiT2 heterodimerization was still regulated by extracellular Pi levels. Of note, when two putative Pi-binding residues, Ser-128 (in PiT1) and Ser-113 (in PiT2), were substituted with alanine, the PiT1-PiT2 heterodimerization was no longer regulated by extracellular Pi These observations suggested that Pi binding rather than Pi uptake may be the key factor in mediating Pi signaling through the PiT proteins. Taken together, these results demonstrate that Pi-regulated PiT1-PiT2 heterodimerization mediates Pi sensing independently of Pi uptake.
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Affiliation(s)
- Nina Bon
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Greig Couasnay
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Annabelle Bourgine
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Sophie Sourice
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Sarah Beck-Cormier
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
| | - Jérôme Guicheux
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France.,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and.,CHU Nantes, PHU 4 OTONN, Nantes F-44042, France
| | - Laurent Beck
- From INSERM, U1229, RMeS "Regenerative Medicine and Skeleton," STEP team "Skeletal Physiopathology and Joint Regenerative Medicine," Nantes F-44042, France, .,the Université de Nantes, UMR-S 1229, RMeS, UFR Odontologie, Nantes F-44042, France, and
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29
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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: 59] [Impact Index Per Article: 8.4] [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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30
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SNAT7 is the primary lysosomal glutamine exporter required for extracellular protein-dependent growth of cancer cells. Proc Natl Acad Sci U S A 2017; 114:E3602-E3611. [PMID: 28416685 DOI: 10.1073/pnas.1617066114] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Lysosomes degrade cellular components sequestered by autophagy or extracellular material internalized by endocytosis and phagocytosis. The macromolecule building blocks released by lysosomal hydrolysis are then exported to the cytosol by lysosomal transporters, which remain undercharacterized. In this study, we designed an in situ assay of lysosomal amino acid export based on the transcription factor EB (TFEB), a master regulator of lysosomal biogenesis that detects lysosomal storage. This assay was used to screen candidate lysosomal transporters, leading to the identification of sodium-coupled neutral amino acid transporter 7 (SNAT7), encoded by the SLC38A7 gene, as a lysosomal transporter highly selective for glutamine and asparagine. Cell fractionation confirmed the lysosomal localization of SNAT7, and flux measurements confirmed its substrate selectivity and showed a strong activation by the lysosomal pH gradient. Interestingly, gene silencing or editing experiments revealed that SNAT7 is the primary permeation pathway for glutamine across the lysosomal membrane and it is required for growth of cancer cells in a low free-glutamine environment, when macropinocytosis and lysosomal degradation of extracellular proteins are used as an alternative source of amino acids. SNAT7 may, thus, represent a novel target for glutamine-related anticancer therapies.
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31
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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: 36] [Impact Index Per Article: 5.1] [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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32
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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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33
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Le Plénier S, Goron A, Sotiropoulos A, Archambault E, Guihenneuc C, Walrand S, Salles J, Jourdan M, Neveux N, Cynober L, Moinard C. Citrulline directly modulates muscle protein synthesis via the PI3K/MAPK/4E-BP1 pathway in a malnourished state: evidence from in vivo, ex vivo, and in vitro studies. Am J Physiol Endocrinol Metab 2017; 312:E27-E36. [PMID: 27827806 DOI: 10.1152/ajpendo.00203.2016] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2016] [Revised: 10/13/2016] [Accepted: 10/18/2016] [Indexed: 12/16/2022]
Abstract
Citrulline (CIT) is an endogenous amino acid produced by the intestine. Recent literature has consistently shown CIT to be an activator of muscle protein synthesis (MPS). However, the underlying mechanism is still unknown. Our working hypothesis was that CIT might regulate muscle homeostasis directly through the mTORC1/PI3K/MAPK pathways. Because CIT undergoes both interorgan and intraorgan trafficking and metabolism, we combined three approaches: in vivo, ex vivo, and in vitro. Using a model of malnourished aged rats, CIT supplementation activated the phosphorylation of S6K1 and 4E-BP1 in muscle. Interestingly, the increase in S6K1 phosphorylation was positively correlated (P < 0.05) with plasma CIT concentration. In a model of isolated incubated skeletal muscle from malnourished rats, CIT enhanced MPS (from 30 to 80% CIT vs. Ctrl, P < 0.05), and the CIT effect was abolished in the presence of wortmannin, rapamycin, and PD-98059. In vitro, on myotubes in culture, CIT led to a 2.5-fold increase in S6K1 phosphorylation and a 1.5-fold increase in 4E-BP1 phosphorylation. Both rapamycin and PD-98059 inhibited the CIT effect on S6K1, whereas only LY-294002 inhibited the CIT effect on both S6K1 and 4E-BP1. These findings show that CIT is a signaling agent for muscle homeostasis, suggesting a new role of the intestine in muscle mass control.
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Affiliation(s)
- Servane Le Plénier
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France;
| | - Arthur Goron
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Athanassia Sotiropoulos
- Centre National de la Recherche Scientifique UMR 8104, Institut Cochin, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Eliane Archambault
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Chantal Guihenneuc
- Laboratoire d'épidémiologie environnementale, EA 4064, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Stéphane Walrand
- Unité de Nutrition humaine, UMR 1019, Institut National de la Recherche Agronomique/Université d'Auvergne, Centre de Recherche en Nutrition Humaine, Auvergne, Clermont-Ferrand, France; and
| | - Jérome Salles
- Unité de Nutrition humaine, UMR 1019, Institut National de la Recherche Agronomique/Université d'Auvergne, Centre de Recherche en Nutrition Humaine, Auvergne, Clermont-Ferrand, France; and
| | - Marion Jourdan
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Nathalie Neveux
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
| | - Luc Cynober
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
- Service de Biochimie interhospitalier Cochin et Hôtel-Dieu, GH Hôpitaux universitaire Paris Centre, AP-HP, Paris, France
| | - Christophe Moinard
- Laboratoire de Biologie de la Nutrition, EA4466, Faculté de Pharmacie, Université Paris Descartes, Sorbonne-Paris-Cité, Paris, France
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34
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Grañé-Boladeras N, Pérez-Torras S, Lozano JJ, Romero MR, Mazo A, Marín JJ, Pastor-Anglada M. Pharmacogenomic analyzis of the responsiveness of gastrointestinal tumor cell lines to drug therapy: A transportome approach. Pharmacol Res 2016; 113:364-375. [DOI: 10.1016/j.phrs.2016.09.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 08/17/2016] [Accepted: 09/07/2016] [Indexed: 01/20/2023]
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35
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Amino acids regulate mTOR pathway and milk protein synthesis in a mouse mammary epithelial cell line is partly mediated by T1R1/T1R3. Eur J Nutr 2016; 56:2467-2474. [DOI: 10.1007/s00394-016-1282-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 07/20/2016] [Indexed: 12/18/2022]
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36
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Scalise M, Pochini L, Galluccio M, Indiveri C. Glutamine transport. From energy supply to sensing and beyond. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2016; 1857:1147-1157. [PMID: 26951943 DOI: 10.1016/j.bbabio.2016.03.006] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 03/01/2016] [Accepted: 03/02/2016] [Indexed: 12/16/2022]
Abstract
Glutamine is the most abundant amino acid in plasma and is actively involved in many biosynthetic and regulatory processes. It can be synthesized endogenously but becomes "conditionally essential" in physiological or pathological conditions of high proliferation rate. To accomplish its functions glutamine has to be absorbed and distributed in the whole body. This job is efficiently carried out by a network of membrane transporters that differ in transport mechanisms and energetics, belonging to families SLC1, 6, 7, 38, and possibly, 25. Some of the transporters are involved in glutamine traffic across different membranes for metabolic purposes; others are involved in specific signaling functions through mTOR. Structure/function relationships and regulatory aspects of glutamine transporters are still at infancy. In the while, insights in involvement of these transporters in cell redox control, cancer metabolism and drug interactions are arising, stimulating basic research to uncover molecular mechanisms of transport and regulation. This article is part of a Special Issue entitled 'EBEC 2016: 19th European Bioenergetics Conference, Riva del Garda, Italy, July 2-6, 2016', edited by Prof. Paolo Bernardi.
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Affiliation(s)
- Mariafrancesca Scalise
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Lorena Pochini
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Michele Galluccio
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy
| | - Cesare Indiveri
- Department DiBEST (Biologia, Ecologia, Scienze della Terra) Unit of Biochemistry and Molecular Biotechnology, University of Calabria, Via P. Bucci 4C, 87036 Arcavacata di Rende, Italy.
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37
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Roy A, Hashmi S, Li Z, Dement AD, Cho KH, Kim JH. The glucose metabolite methylglyoxal inhibits expression of the glucose transporter genes by inactivating the cell surface glucose sensors Rgt2 and Snf3 in yeast. Mol Biol Cell 2016; 27:862-71. [PMID: 26764094 PMCID: PMC4803311 DOI: 10.1091/mbc.e15-11-0789] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2015] [Accepted: 01/05/2016] [Indexed: 01/04/2023] Open
Abstract
Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG inhibits the growth of glucose-fermenting yeast cells by inhibiting glycolysis. MG does so by inducing endocytosis and degradation of the cell-surface glucose sensors Rgt2 and Snf3, which are required for glucose induction of HXT (glucose transporter) gene expression. Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG has inhibitory effect on the growth of cells ranging from microorganisms to higher eukaryotes, but its molecular targets are largely unknown. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of expression of genes encoding glucose transporters (HXTs). Here we provide evidence that these glucose sensors are primary targets of MG in yeast. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensors. However, the glucose sensors with mutations at their putative ubiquitin-acceptor lysine residues are resistant to MG-induced degradation. These results suggest that the glucose sensors are inactivated through ubiquitin-mediated endocytosis and degraded in the presence of MG. In addition, the inhibitory effect of MG on the glucose sensors is greatly enhanced in cells lacking Glo1, a key component of the MG detoxification system. Thus the stability of these glucose sensors seems to be critically regulated by intracellular MG levels. Taken together, these findings suggest that MG attenuates glycolysis by promoting degradation of the cell-surface glucose sensors and thus identify MG as a potential glycolytic inhibitor.
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Affiliation(s)
- Adhiraj Roy
- Department of Biochemistry and Molecular Medicine, George Washington University School of Medicine and Health Science, Washington, DC 20037
| | - Salman Hashmi
- Department of Biochemistry and Molecular Medicine, George Washington University School of Medicine and Health Science, Washington, DC 20037
| | - Zerui Li
- Department of Biochemistry and Molecular Medicine, George Washington University School of Medicine and Health Science, Washington, DC 20037
| | - Angela D Dement
- Virginia Bioinformatics Institute, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061
| | - Kyu Hong Cho
- Department of Biology, Indiana State University, Terre Haute, IN 47809
| | - Jeong-Ho Kim
- Department of Biochemistry and Molecular Medicine, George Washington University School of Medicine and Health Science, Washington, DC 20037
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38
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The Renaissance of Neurospora crassa: How a Classical Model System is Used for Applied Research. Fungal Biol 2016. [DOI: 10.1007/978-3-319-27951-0_3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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39
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Samyn DR, Persson BL. Inorganic Phosphate and Sulfate Transport in S. cerevisiae. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 892:253-269. [PMID: 26721277 DOI: 10.1007/978-3-319-25304-6_10] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Inorganic ions such as phosphate and sulfate are essential macronutrients required for a broad spectrum of cellular functions and their regulation. In a constantly fluctuating environment microorganisms have for their survival developed specific nutrient sensing and transport systems ensuring that the cellular nutrient needs are met. This chapter focuses on the S. cerevisiae plasma membrane localized transporters, of which some are strongly induced under conditions of nutrient scarcity and facilitate the active uptake of inorganic phosphate and sulfate. Recent advances in studying the properties of the high-affinity phosphate and sulfate transporters by means of site-directed mutagenesis have provided further insight into the molecular mechanisms contributing to substrate selectivity and transporter functionality of this important class of membrane transporters.
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Affiliation(s)
- D R Samyn
- Department of Chemistry and Biomedical Sciences, Centre for Biomaterials Chemistry, Linnaeus University, 391 82, Kalmar, Sweden.
| | - B L Persson
- Department of Chemistry and Biomedical Sciences, Centre for Biomaterials Chemistry, Linnaeus University, 391 82, Kalmar, Sweden
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40
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Sun J, Zheng N. Molecular Mechanism Underlying the Plant NRT1.1 Dual-Affinity Nitrate Transporter. Front Physiol 2015; 6:386. [PMID: 26733879 PMCID: PMC4683204 DOI: 10.3389/fphys.2015.00386] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 11/30/2015] [Indexed: 11/13/2022] Open
Abstract
Nitrate ([Formula: see text]) is one of the most important sources of mineral nitrogen, which also serves as a key signaling molecule for plant growth and development. To cope with nitrate fluctuation in soil that varies by up to four orders of magnitude, plants have evolved high- and low-affinity nitrate transporter systems, consisting of distinct families of transporters. Interestingly, the first cloned nitrate transporter in Arabidopsis, NRT1.1 functions as a dual-affinity transporter, which can change its affinity for nitrate in response to substrate availability. Phosphorylation of a threonine residue, Thr101, switches NRT1.1 from low- to high-affinity state. Recent structural studies have unveiled that the unmodified NRT1.1 transporter works as homodimers with Thr101 located in close proximity to the dimer interface. Modification on the Thr101 residue is shown to not only decouple the dimer configuration, but also increase structural flexibility, thereby, altering the substrate affinity of NRT1.1. The structure of NRT1.1 helps establish a novel paradigm in which protein oligomerzation and posttranslational modification can synergistically expand the functional capacity of the major facilitator superfamily (MFS) transporters.
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Affiliation(s)
- Ji Sun
- Department of Pharmacology, University of Washington Seattle, WA, USA
| | - Ning Zheng
- Department of Pharmacology, University of WashingtonSeattle, WA, USA; Howard Hughes Medical Institute, University of WashingtonSeattle, WA, USA
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Wu W, Bush KT, Liu HC, Zhu C, Abagyan R, Nigam SK. Shared Ligands Between Organic Anion Transporters (OAT1 and OAT6) and Odorant Receptors. Drug Metab Dispos 2015; 43:1855-63. [PMID: 26358290 DOI: 10.1124/dmd.115.065250] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 09/04/2015] [Indexed: 12/31/2022] Open
Abstract
The multispecific organic anion drug transporters OAT6 (SLC22A20) and OAT1 (SLC22A6) are expressed in nasal epithelial cells and both can bind odorants. Sequence analysis of OAT6 revealed an evolutionarily conserved 79-amino acid (AA) fragment present not only in OAT6 but also in other SLC22 transporters, such as the organic anion transporter (OAT), organic carnitine transporter (OCTN), and organic cation transporter (OCT) subfamilies. A similar fragment is also conserved in some odorant receptors (ORs) in both humans and rodents. This fragment is located in regions believed to be important for ligand/substrate preference and recognition in both classes of proteins, raising the possibility that it may be part of a potential common ligand/substrate recognition site in certain ORs and SLC22 transporters. In silico screening of an odorant database containing known OR ligands with a pharmacophore hypothesis (generated from a set of odorants known to bind OAT6 and/or OAT1), followed by in vitro uptake assays in transfected cells, identified OR ligands capable of inhibiting OAT6- and/or OAT1-mediated transport, albeit with different affinities. The conservation of the AA fragments between these two different classes of proteins, together with their coexpression in olfactory as well as other tissues, suggests the possibility that ORs and SLC22 transporters function in concert, and raises the question as to whether these transporters function in remote sensing and signaling and/or as transceptors.
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Affiliation(s)
- Wei Wu
- Departments of Pediatrics (K.T.B., S.K.N.), Medicine (Division of Nephrology and Hypertension)(W.W., S.K.N.), Bioengineering (H.C.L.), Biomedical Sciences (C.Z.), School of Pharmacy/Pharmaceutical Science (R.A.), and Cellular and Molecular Medicine (S.K.N.), University of California, San Diego, La Jolla, California
| | - Kevin T Bush
- Departments of Pediatrics (K.T.B., S.K.N.), Medicine (Division of Nephrology and Hypertension)(W.W., S.K.N.), Bioengineering (H.C.L.), Biomedical Sciences (C.Z.), School of Pharmacy/Pharmaceutical Science (R.A.), and Cellular and Molecular Medicine (S.K.N.), University of California, San Diego, La Jolla, California
| | - Henry C Liu
- Departments of Pediatrics (K.T.B., S.K.N.), Medicine (Division of Nephrology and Hypertension)(W.W., S.K.N.), Bioengineering (H.C.L.), Biomedical Sciences (C.Z.), School of Pharmacy/Pharmaceutical Science (R.A.), and Cellular and Molecular Medicine (S.K.N.), University of California, San Diego, La Jolla, California
| | - Christopher Zhu
- Departments of Pediatrics (K.T.B., S.K.N.), Medicine (Division of Nephrology and Hypertension)(W.W., S.K.N.), Bioengineering (H.C.L.), Biomedical Sciences (C.Z.), School of Pharmacy/Pharmaceutical Science (R.A.), and Cellular and Molecular Medicine (S.K.N.), University of California, San Diego, La Jolla, California
| | - Ruben Abagyan
- Departments of Pediatrics (K.T.B., S.K.N.), Medicine (Division of Nephrology and Hypertension)(W.W., S.K.N.), Bioengineering (H.C.L.), Biomedical Sciences (C.Z.), School of Pharmacy/Pharmaceutical Science (R.A.), and Cellular and Molecular Medicine (S.K.N.), University of California, San Diego, La Jolla, California
| | - Sanjay K Nigam
- Departments of Pediatrics (K.T.B., S.K.N.), Medicine (Division of Nephrology and Hypertension)(W.W., S.K.N.), Bioengineering (H.C.L.), Biomedical Sciences (C.Z.), School of Pharmacy/Pharmaceutical Science (R.A.), and Cellular and Molecular Medicine (S.K.N.), University of California, San Diego, La Jolla, California
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Lin WY, Williams C, Yan C, Koledachkina T, Luedke K, Dalton J, Bloomsburg S, Morrison N, Duncan KE, Kim CC, Parrish JZ. The SLC36 transporter Pathetic is required for extreme dendrite growth in Drosophila sensory neurons. Genes Dev 2015; 29:1120-35. [PMID: 26063572 PMCID: PMC4470281 DOI: 10.1101/gad.259119.115] [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] [Indexed: 11/30/2022]
Abstract
Lin et al. identified a mutant that selectively affects dendrite growth in neurons with large dendrite arbors without affecting dendrite growth in neurons with small dendrite arbors or the animal overall. This mutant disrupts a putative amino acid transporter, Pathetic (Path), that localizes to the cell surface and endolysosomal compartments in neurons. Dendrites exhibit enormous diversity in form and can differ in size by several orders of magnitude even in a single animal. However, whether neurons with large dendrite arbors have specialized mechanisms to support their growth demands is unknown. To address this question, we conducted a genetic screen for mutations that differentially affected growth in neurons with different-sized dendrite arbors. From this screen, we identified a mutant that selectively affects dendrite growth in neurons with large dendrite arbors without affecting dendrite growth in neurons with small dendrite arbors or the animal overall. This mutant disrupts a putative amino acid transporter, Pathetic (Path), that localizes to the cell surface and endolysosomal compartments in neurons. Although Path is broadly expressed in neurons and nonneuronal cells, mutation of path impinges on nutrient responses and protein homeostasis specifically in neurons with large dendrite arbors but not in other cells. Altogether, our results demonstrate that specialized molecular mechanisms exist to support growth demands in neurons with large dendrite arbors and define Path as a founding member of this growth program.
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Affiliation(s)
- Wen-Yang Lin
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Claire Williams
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Connie Yan
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Tatyana Koledachkina
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
| | - Kory Luedke
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Jesse Dalton
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Sam Bloomsburg
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Nicole Morrison
- Department of Biology, University of Washington, Seattle, Washington 98195, USA
| | - Kent E Duncan
- Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf, Hamburg D-20251, Germany
| | - Charles C Kim
- Division of Experimental Medicine, Department of Medicine, University of California at San Francisco, San Francisco, California 94110, USA
| | - Jay Z Parrish
- Department of Biology, University of Washington, Seattle, Washington 98195, USA;
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43
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Landfear SM, Tran KD, Sanchez MA. Flagellar membrane proteins in kinetoplastid parasites. IUBMB Life 2015; 67:668-76. [PMID: 26599841 DOI: 10.1002/iub.1411] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2015] [Accepted: 08/06/2015] [Indexed: 11/06/2022]
Abstract
All kinetoplastid parasites, including protozoa such as Leishmania species, Trypanosoma brucei, and Trypanosoma cruzi that cause devastating diseases in humans and animals, are flagellated throughout their life cycles. Although flagella were originally thought of primarily as motility organelles, flagellar functions in other critical processes, especially in sensing and signal transduction, have become more fully appreciated in the recent past. The flagellar membrane is a highly specialized subdomain of the surface membrane, and flagellar membrane proteins are likely to be critical components for all the biologically important roles of flagella. In this review, we summarize recent discoveries relevant to flagellar membrane proteins in these parasites, including the identification of such proteins, investigation of their biological functions, and mechanisms of selective trafficking to the flagellar membrane. Prospects for future investigations and current unsolved problems are highlighted.
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Affiliation(s)
- Scott M Landfear
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Khoa D Tran
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
| | - Marco A Sanchez
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, Portland, OR, USA
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Role of the Transporter-Like Sensor Kinase CbrA in Histidine Uptake and Signal Transduction. J Bacteriol 2015; 197:2867-78. [PMID: 26148710 DOI: 10.1128/jb.00361-15] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 06/17/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED CbrA is an atypical sensor kinase found in Pseudomonas. The autokinase domain is connected to a putative transporter of the sodium/solute symporter family (SSSF). CbrA functions together with its cognate response regulator, CbrB, and plays an important role in nutrient acquisition, including regulation of hut genes for the utilization of histidine and its derivative, urocanate. Here we report on the findings of a genetic and biochemical analysis of CbrA with a focus on the function of the putative transporter domain. The work was initiated with mutagenesis of histidine uptake-proficient strains to identify histidine-specific transport genes located outside the hut operon. Genes encoding transporters were not identified, but mutations were repeatedly found in cbrA. This, coupled with the findings of [(3)H]histidine transport assays and further mutagenesis, implicated CbrA in histidine uptake. In addition, mutations in different regions of the SSSF domain abolished signal transduction. Site-specific mutations were made at four conserved residues: W55 and G172 (SSSF domain), H766 (H box), and N876 (N box). The mutations W55G, G172H, and N876G compromised histidine transport but had minimal effects on signal transduction. The H766G mutation abolished both transport and signal transduction, but the capacity to transport histidine was restored upon complementation with a transport-defective allele of CbrA, most likely due to interdomain interactions. Our combined data implicate the SSSF domain of CbrA in histidine transport and suggest that transport is coupled to signal transduction. IMPORTANCE Nutrient acquisition in bacteria typically involves membrane-bound sensors that, via cognate response regulators, determine the activity of specific transporters. However, nutrient perception and uptake are often coupled processes. Thus, from a physiological perspective, it would make sense for systems that couple the process of signaling and transport within a single protein and where transport is itself the stimulus that precipitates signal transduction to have evolved. The CbrA regulator in Pseudomonas represents a unique type of sensor kinase whose autokinase domain is connected to a transporter domain. We present genetic and biochemical evidence that suggests that CbrA plays a dual role in histidine uptake and sensing and that transport is dependent on signal transduction.
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Abstract
Soluble sugars serve five main purposes in multicellular organisms: as sources of carbon skeletons, osmolytes, signals, and transient energy storage and as transport molecules. Most sugars are derived from photosynthetic organisms, particularly plants. In multicellular organisms, some cells specialize in providing sugars to other cells (e.g., intestinal and liver cells in animals, photosynthetic cells in plants), whereas others depend completely on an external supply (e.g., brain cells, roots and seeds). This cellular exchange of sugars requires transport proteins to mediate uptake or release from cells or subcellular compartments. Thus, not surprisingly, sugar transport is critical for plants, animals, and humans. At present, three classes of eukaryotic sugar transporters have been characterized, namely the glucose transporters (GLUTs), sodium-glucose symporters (SGLTs), and SWEETs. This review presents the history and state of the art of sugar transporter research, covering genetics, biochemistry, and physiology-from their identification and characterization to their structure, function, and physiology. In humans, understanding sugar transport has therapeutic importance (e.g., addressing diabetes or limiting access of cancer cells to sugars), and in plants, these transporters are critical for crop yield and pathogen susceptibility.
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Affiliation(s)
- Li-Qing Chen
- Department of Plant Biology, Carnegie Institution for Science, Stanford, California 94305;
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46
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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: 38] [Impact Index Per Article: 4.2] [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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47
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Rodriguez-Contreras D, Landfear SM. Transporters, channels and receptors in flagella. Channels (Austin) 2014; 8:477-8. [PMID: 25485659 DOI: 10.4161/19336950.2014.985481] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Affiliation(s)
- Dayana Rodriguez-Contreras
- a Department of Molecular Microbiology & Immunology ; Oregon Health Sciences University ; Portland , OR USA
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48
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Cai P, Wang B, Ji J, Jiang Y, Wan L, Tian C, Ma Y. The putative cellodextrin transporter-like protein CLP1 is involved in cellulase induction in Neurospora crassa. J Biol Chem 2014; 290:788-96. [PMID: 25398875 DOI: 10.1074/jbc.m114.609875] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Neurospora crassa recently has become a novel system to investigate cellulase induction. Here, we discovered a novel membrane protein, cellodextrin transporter-like protein 1 (CLP1; NCU05853), a putative cellodextrin transporter-like protein that is a critical component of the cellulase induction pathway in N. crassa. Although CLP1 protein cannot transport cellodextrin, the suppression of cellulase induction by this protein was discovered on both cellobiose and Avicel. The co-disruption of the cellodextrin transporters cdt2 and clp1 in strain Δ3βG formed strain CPL7. With induction by cellobiose, cellulase production was enhanced 6.9-fold in CPL7 compared with Δ3βG. We also showed that the suppression of cellulase expression by CLP1 occurred by repressing the expression of cellodextrin transporters, particularly cdt1 expression. Transcriptome analysis of the hypercellulase-producing strain CPL7 showed that the cellulase expression machinery was dramatically stimulated, as were the cellulase enzyme genes including the inducer transporters and the major transcriptional regulators.
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Affiliation(s)
- Pengli Cai
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Bang Wang
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Jingxiao Ji
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yongsheng Jiang
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Li Wan
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Chaoguang Tian
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yanhe Ma
- From the Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
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49
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Rodriguez-Contreras D, Aslan H, Feng X, Tran K, Yates PA, Kamhawi S, Landfear SM. Regulation and biological function of a flagellar glucose transporter in Leishmania mexicana: a potential glucose sensor. FASEB J 2014; 29:11-24. [PMID: 25300620 DOI: 10.1096/fj.14-251991] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
In Leishmania mexicana parasites, a unique glucose transporter, LmxGT1, is selectively targeted to the flagellar membrane, suggesting a possible sensory role that is often associated with ciliary membrane proteins. Expression of LmxGT1 is down-regulated ∼20-fold by increasing cell density but is up-regulated ∼50-fold by depleting glucose from the medium, and the permease is strongly down-regulated when flagellated insect-stage promastigotes invade mammalian macrophages and transform into intracellular amastigotes. Regulation of LmxGT1 expression by glucose and during the lifecycle operates at the level of protein stability. Significantly, a ∆lmxgt1 null mutant, grown in abundant glucose, undergoes catastrophic loss of viability when parasites deplete glucose from the medium, a property not exhibited by wild-type or add-back lines. These results suggest that LmxGT1 may function as a glucose sensor that allows parasites to enter the stationary phase when they deplete glucose and that in the absence of this sensor, parasites do not maintain viability when they run out of glucose. However, alternate roles for LmxGT1 in monitoring glucose availability are considered. The absence of known sensory receptors with defined ligands and biologic functions in Leishmania and related kinetoplastid parasites underscores the potential significance of these observations.
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Affiliation(s)
| | - Hamide Aslan
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
| | - Xiuhong Feng
- Departments of Molecular Microbiology & Immunology and
| | - Khoa Tran
- Departments of Molecular Microbiology & Immunology and
| | - Phillip A Yates
- Biochemistry & Molecular Biology, Oregon Health & Science University, Portland, Oregon, USA; and
| | - Shaden Kamhawi
- Laboratory of Parasitic Diseases, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA
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50
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Johswich A, Longuet C, Pawling J, Abdel Rahman A, Ryczko M, Drucker DJ, Dennis JW. N-glycan remodeling on glucagon receptor is an effector of nutrient sensing by the hexosamine biosynthesis pathway. J Biol Chem 2014; 289:15927-41. [PMID: 24742675 DOI: 10.1074/jbc.m114.563734] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Glucose homeostasis in mammals is dependent on the opposing actions of insulin and glucagon. The Golgi N-acetylglucosaminyltransferases encoded by Mgat1, Mgat2, Mgat4a/b/c, and Mgat5 modify the N-glycans on receptors and solute transporter, possibly adapting activities in response to the metabolic environment. Herein we report that Mgat5(-/-) mice display diminished glycemic response to exogenous glucagon, together with increased insulin sensitivity. Glucagon receptor signaling and gluconeogenesis in Mgat5(-/-) cultured hepatocytes was impaired. In HEK293 cells, signaling by ectopically expressed glucagon receptor was increased by Mgat5 expression and GlcNAc supplementation to UDP-GlcNAc, the donor substrate shared by Mgat branching enzymes. The mobility of glucagon receptor in primary hepatocytes was reduced by galectin-9 binding, and the strength of the interaction was dependent on Mgat5 and UDP-GlcNAc levels. Finally, oral GlcNAc supplementation rescued the glucagon response in Mgat5(-/-) hepatocytes and mice, as well as glycolytic metabolites and UDP-GlcNAc levels in liver. Our results reveal that the hexosamine biosynthesis pathway and GlcNAc salvage contribute to glucose homeostasis through N-glycan branching on glucagon receptor.
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Affiliation(s)
- Anita Johswich
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and
| | - Christine Longuet
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and
| | - Judy Pawling
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and
| | - Anas Abdel Rahman
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and
| | - Michael Ryczko
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and the Departments of Molecular Genetics
| | - Daniel J Drucker
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and Medicine, University of Toronto, Toronto, Ontario M5R 0A3, Canada
| | - James W Dennis
- From the Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, Ontario M5G 1X5, Canada and the Departments of Molecular Genetics, Laboratory Medicine and Pathology, and Medicine, University of Toronto, Toronto, Ontario M5R 0A3, Canada
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