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Trichez D, Knychala MM, Figueiredo CM, Alves SL, da Silva MA, Miletti LC, de Araujo PS, Stambuk BU. Key amino acid residues of the AGT1 permease required for maltotriose consumption and fermentation by Saccharomyces cerevisiae. J Appl Microbiol 2018; 126:580-594. [PMID: 30466168 DOI: 10.1111/jam.14161] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 10/22/2018] [Accepted: 11/10/2018] [Indexed: 12/24/2022]
Abstract
AIMS The AGT1 gene encodes for a general α-glucoside-H+ symporter required for efficient maltotriose fermentation by Saccharomyces cerevisiae. In the present study, we analysed the involvement of four charged amino acid residues present in this transporter that are required for maltotriose consumption and fermentation by yeast cells. METHODS AND RESULTS By using a knowledge-driven approach based on charge, conservation, location, three-dimensional (3D) structural modelling and molecular docking analysis, we identified four amino acid residues (Glu-120, Asp-123, Glu-167 and Arg-504) in the AGT1 permease that could mediate substrate binding and translocation. Mutant permeases were generated by site-directed mutagenesis of these charged residues, and expressed in a yeast strain lacking this permease (agt1∆). While mutating the Arg-504 or Glu-120 residues into alanine totally abolished (R504A mutant) or greatly reduced (E120A mutant) maltotriose consumption by yeast cells, as well as impaired the active transport of several other α-glucosides, in the case of the Asp-123 and Glu-167 amino acids, it was necessary to mutate both residues (D123G/E167A mutant) in order to impair maltotriose consumption and fermentation. CONCLUSIONS Based on the results obtained with mutant proteins, molecular docking and the localization of amino acid residues, we propose a transport mechanism for the AGT1 permease. SIGNIFICANCE AND IMPACT OF THE STUDY Our results present new insights into the structural basis for active α-glucoside-H+ symport activity by yeast transporters, providing the molecular bases for improving the catalytic properties of this type of sugar transporters.
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Affiliation(s)
- D Trichez
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.,Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - M M Knychala
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - C M Figueiredo
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.,Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - S L Alves
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - M A da Silva
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - L C Miletti
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - P S de Araujo
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil
| | - B U Stambuk
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
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2
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Henderson RK, Fendler K, Poolman B. Coupling efficiency of secondary active transporters. Curr Opin Biotechnol 2018; 58:62-71. [PMID: 30502621 DOI: 10.1016/j.copbio.2018.11.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
Abstract
Secondary active transporters are fundamental to a myriad of biological processes. They use the electrochemical gradient of one solute to drive transport of another solute against its concentration gradient. Central to this mechanism is that the transport of one does not occur in the absence of the other. However, like in most of biology, imperfections in the coupling mechanism exist and we argue that these are innocuous and may even be beneficial for the cell. We discuss the energetics and kinetics of alternating-access in secondary transport and focus on the mechanistic aspects of imperfect coupling that give rise to leak pathways. Additionally, inspection of available transporter structures gives valuable insight into coupling mechanics, and we review literature where proteins have been altered to change their coupling efficiency.
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Affiliation(s)
- Ryan K Henderson
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - Klaus Fendler
- Department of Biophysical Chemistry, Max-Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Bert Poolman
- Department of Biochemistry, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
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3
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Inhibition of Saccharomyces cerevisiae growth by simultaneous uptake of glucose and maltose. J Biosci Bioeng 2018; 125:52-58. [DOI: 10.1016/j.jbiosc.2017.07.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Revised: 07/18/2017] [Accepted: 07/21/2017] [Indexed: 11/18/2022]
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4
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Yoshida A, Wei D, Nomura W, Izawa S, Inoue Y. Reduction of glucose uptake through inhibition of hexose transporters and enhancement of their endocytosis by methylglyoxal in Saccharomyces cerevisiae. J Biol Chem 2011; 287:701-711. [PMID: 22094464 DOI: 10.1074/jbc.m111.322222] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Diabetes mellitus is characterized by an impairment of glucose uptake even though blood glucose levels are increased. Methylglyoxal is derived from glycolysis and has been implicated in the development of diabetes mellitus, because methylglyoxal levels in blood and tissues are higher in diabetic patients than in healthy individuals. However, it remains to be elucidated whether such factors are a cause, or consequence, of diabetes. Here, we show that methylglyoxal inhibits the activity of mammalian glucose transporters using recombinant Saccharomyces cerevisiae cells genetically lacking all hexose transporters but carrying cDNA for human GLUT1 or rat GLUT4. We found that methylglyoxal inhibits yeast hexose transporters also. Glucose uptake was reduced in a stepwise manner following treatment with methylglyoxal, i.e. a rapid reduction within 5 min, followed by a slow and gradual reduction. The rapid reduction was due to the inhibitory effect of methylglyoxal on hexose transporters, whereas the slow and gradual reduction seemed due to endocytosis, which leads to a decrease in the amount of hexose transporters on the plasma membrane. We found that Rsp5, a HECT-type ubiquitin ligase, is responsible for the ubiquitination of hexose transporters. Intriguingly, Plc1 (phospholipase C) negatively regulated the endocytosis of hexose transporters in an Rsp5-dependent manner, although the methylglyoxal-induced endocytosis of hexose transporters occurred irrespective of Plc1. Meanwhile, the internalization of hexose transporters following treatment with methylglyoxal was delayed in a mutant defective in protein kinase C.
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Affiliation(s)
- Aya Yoshida
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Dandan Wei
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Wataru Nomura
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Shingo Izawa
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Yoshiharu Inoue
- Laboratory of Molecular Microbiology, Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Uji, Kyoto 611-0011, Japan.
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5
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Teste MA, François JM, Parrou JL. Characterization of a new multigene family encoding isomaltases in the yeast Saccharomyces cerevisiae, the IMA family. J Biol Chem 2010; 285:26815-26824. [PMID: 20562106 DOI: 10.1074/jbc.m110.145946] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
It has been known for a long time that the yeast Saccharomyces cerevisiae can assimilate alpha-methylglucopyranoside and isomaltose. We here report the identification of 5 genes (YGR287c, YIL172c, YJL216c, YJL221c and YOL157c), which, similar to the SUCx, MALx, or HXTx multigene families, are located in the subtelomeric regions of different chromosomes. They share high nucleotide sequence identities between themselves (66-100%) and with the MALx2 genes (63-74%). Comparison of their amino acid sequences underlined a substitution of threonine by valine in region II, one of the four highly conserved regions of the alpha-glucosidase family. This change was previously shown to be sufficient to discriminate alpha-1,4- to alpha-1,6-glucosidase activity in YGR287c (Yamamoto, K., Nakayama, A., Yamamoto, Y., and Tabata, S. (2004) Eur. J. Biochem. 271, 3414-3420). We showed that each of these five genes encodes a protein with alpha-glucosidase activity on isomaltose, and we therefore renamed these genes IMA1 to IMA5 for IsoMAltase. Our results also illustrated that sequence polymorphisms among this family led to interesting variability of gene expression patterns and of catalytic efficiencies on different substrates, which altogether should account for the absence of functional redundancy for growth on isomaltose. Indeed, deletion studies revealed that IMA1/YGR287c encodes the major isomaltase and that growth on isomaltose required the presence of AGT1, which encodes an alpha-glucoside transporter. Expressions of IMA1 and IMA5/YJL216c were strongly induced by maltose, isomaltose, and alpha-methylglucopyranoside, in accordance with their regulation by the Malx3p-transcription system. The physiological relevance of this IMAx multigene family in S. cerevisiae is discussed.
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Affiliation(s)
- Marie-Ange Teste
- CNRS, UMR5504, F-31400 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | - Jean Marie François
- CNRS, UMR5504, F-31400 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France
| | - Jean-Luc Parrou
- CNRS, UMR5504, F-31400 Toulouse, France; INRA, UMR792 Ingénierie des Systèmes Biologiques et des Procédés, F-31400 Toulouse, France; Université de Toulouse, INSA, UPS, INP, LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France.
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6
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Hatanaka H, Omura F, Kodama Y, Ashikari T. Gly-46 and His-50 of yeast maltose transporter Mal21p are essential for its resistance against glucose-induced degradation. J Biol Chem 2009; 284:15448-57. [PMID: 19359240 DOI: 10.1074/jbc.m808151200] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The maltose transporter gene is situated at the MAL locus, which consists of genes for a transporter, maltase, and transcriptional activator. Five unlinked MAL loci (MAL1, MAL2, MAL3, MAL4, and MAL6) constitute a gene family in Saccharomyces cerevisiae. The expression of the maltose transporter is induced by maltose and repressed by glucose. The activity of the maltose transporter is also regulated post-translationally; Mal61p is rapidly internalized from the plasma membrane and degraded by ubiquitin-mediated proteolysis in the presence of glucose. We found that S. cerevisiae strain ATCC20598 harboring MAL21 could grow in maltose supplemented with a non- assimilable glucose analogue, 2-deoxyglucose, whereas strain ATCC96955 harboring MAL61 and strain CB11 with MAL31 and AGT1 could not. These observations implied a Mal21p-specific resistance against glucose-induced degradation. Mal21p found in ATCC20598 has 10 amino acids, including Gly-46 and His-50, that are inconsistent with the corresponding residues in Mal61p. The half-life of Mal21p for glucose-induced degradation was 118 min when expressed using the constitutive TPI1 promoter, which was significantly longer than that of Mal61p (25 min). Studies with mutant cells that are defective in endocytosis or the ubiquitination process indicated that Mal21p was less ubiquitinated than Mal61p, suggesting that Mal21p remains on the plasma membrane because of poor susceptibility to ubiquitination. Mutational studies revealed that both residues Gly-46 and His-50 in Mal21p are essential for the full resistance of maltose transporters against glucose-induced degradation.
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Omura F. Targeting of mitochondrial Saccharomyces cerevisiae Ilv5p to the cytosol and its effect on vicinal diketone formation in brewing. Appl Microbiol Biotechnol 2008; 78:503-13. [PMID: 18193418 DOI: 10.1007/s00253-007-1333-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2007] [Revised: 12/11/2007] [Accepted: 12/14/2007] [Indexed: 11/25/2022]
Abstract
Vicinal diketones (VDK) cause butter-like off-flavors in beer and are formed by a non-enzymatic oxidative decarboxylation of alpha-aceto-alpha-hydroxybutyrate and alpha-acetolactate, which are intermediates in isoleucine and valine biosynthesis taking place in the mitochondria. On the assumption that part of alpha-acetolactate can be formed also in the cytosol due to a mislocalization of the responsible acetohydroxyacid synthase encoded by ILV2 and ILV6, functional expression in the cytosol of acetohydroxyacid reductoisomerase (Ilv5p) was explored. Using the cytosolic Ilv5p, I aimed to metabolize the cytosolically formed alpha-aetolactate, thereby lowering the total VDK production. Among mutant Ilv5p enzymes with varying degrees of N-terminal truncation, one with a 46-residue deletion (Ilv5pDelta46) exhibited an unequivocal localization in the cytosol judged from microscopy of the Ilv5pDelta46-green fluorescent protein fusion protein and the inability of Ilv5pDelta46 to remedy the isoleucine/valine requirement of an ilv5Delta strain. When introduced into an industrial lager brewing strain, a robust expression of Ilv5pDelta46 was as effective as that of a wild-type Ilv5p in lowering the total VDK production in a 2-l scale fermentation trial. Unlike the case of the wild-type Ilv5p, an additional expression of Ilv5pDelta46 did not alter the quality of the resultant beer in terms of contents of aromatic compounds and organic acids.
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Affiliation(s)
- Fumihiko Omura
- Suntory Research Center, 1-1-1 Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka, 618-8503, Japan.
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8
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Smit A, Moses SG, Pretorius IS, Cordero Otero RR. The Thr505 and Ser557 residues of the AGT1-encoded alpha-glucoside transporter are critical for maltotriose transport in Saccharomyces cerevisiae. J Appl Microbiol 2008; 104:1103-11. [PMID: 18179544 DOI: 10.1111/j.1365-2672.2007.03671.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS The main objective of this study was to identify amino acid residues in the AGT1-encoded alpha-glucoside transporter (Agt1p) that are critical for efficient transport of maltotriose in the yeast Saccharomyces cerevisiae. METHODS AND RESULTS The sequences of two AGT1-encoded alpha-glucoside transporters with different efficiencies of maltotriose transport in two Saccharomyces strains (WH310 and WH314) were compared. The sequence variations and discrepancies between these two proteins (Agt1p(WH310) and Agt1p(WH314)) were investigated for potential effects on the functionality and maltotriose transport efficiency of these two AGT1-encoded alpha-glucoside transporters. A 23-amino-acid C-terminal truncation proved not to be critical for maltotriose affinity. The identification of three amino acid differences, which potentially could have been instrumental in the transportation of maltotriose, were further investigated. Single mutations were created to restore the point mutations I505T, V549A and T557S one by one. The single site mutant V549A showed a decrease in maltotriose transport ability, and the I505T and T557S mutants showed complete reduction in maltotriose transport. CONCLUSIONS The amino acids Thr(505) and Ser(557), which are respectively located in the transmembrane (TM) segment TM(11) and on the intracellular segment after TM(12) of the AGT1-encoded alpha-glucoside transporters, are critical for efficient transport of maltotriose in S. cerevisiae. SIGNIFICANCE AND IMPACT OF THE STUDY Improved fermentation of starch and its dextrin products, such as maltotriose and maltose, would benefit the brewing and whisky industries. This study could facilitate the development of engineered maltotriose transporters adapted to starch-efficient fermentation systems, and offers prospects for the development of yeast strains with improved maltose and maltotriose uptake capabilities that, in turn, could increase the overall fermentation efficiencies in the beer and whisky industries.
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Affiliation(s)
- A Smit
- Institute for Wine Biotechnology, Department of Viticulture and Oenology, Stellenbosch University, Matieland, South Africa
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9
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van Suylekom D, van Donselaar E, Blanchetot C, Do Ngoc LN, Humbel BM, Boonstra J. Degradation of the hexose transporter Hxt5p in Saccharomyces cerevisiae. Biol Cell 2007; 99:13-23. [PMID: 16928197 DOI: 10.1042/bc20060040] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
BACKGROUND INFORMATION Hxt5p is a member of a multigene family of hexose transporter proteins which translocate glucose across the plasma membrane of the yeast Saccharomyces cerevisiae. In contrast with other major hexose transporters of this family, Hxt5p expression is regulated by the growth rate of the cells and not by the external glucose concentration. Furthermore, Hxt5p is the only glucose transporter expressed during stationary phase. These observations suggest a different role for Hxt5p in S. cerevisiae. Therefore we studied the metabolism and localization of Hxt5p in more detail. RESULTS AND CONCLUSIONS Inhibition of HXT5 expression in stationary-phase cells by the addition of glucose, which increases the growth rate, led to a decrease in the amount of Hxt5 protein within a few hours. Addition of glucose to stationary-phase cells resulted in a transient phosphorylation of Hxt5p on serine residues, but no ubiquitination was detected. The decrease in Hxt5p levels is caused by internalization of the protein, as observed by immunofluorescence microscopy. In stationary-phase cells, Hxt5p was localized predominantly at the cell periphery and upon addition of glucose to the cells the protein translocated to the cell interior. Electron microscopy demonstrated that the internalized Hxt5p-HA (haemagglutinin) protein was localized to small vesicles, multivesicular bodies and the vacuole. These results suggest that internalization and degradation of Hxt5p in the vacuole occur in an ubiquitination-independent manner via the endocytic pathway.
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Affiliation(s)
- Denise van Suylekom
- Cellular Architecture and Dynamics, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
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10
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Jansen MLA, Daran-Lapujade P, de Winde JH, Piper MDW, Pronk JT. Prolonged maltose-limited cultivation of Saccharomyces cerevisiae selects for cells with improved maltose affinity and hypersensitivity. Appl Environ Microbiol 2004; 70:1956-63. [PMID: 15066785 PMCID: PMC383169 DOI: 10.1128/aem.70.4.1956-1963.2004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2003] [Accepted: 12/22/2003] [Indexed: 11/20/2022] Open
Abstract
Prolonged cultivation (>25 generations) of Saccharomyces cerevisiae in aerobic, maltose-limited chemostat cultures led to profound physiological changes. Maltose hypersensitivity was observed when cells from prolonged cultivations were suddenly exposed to excess maltose. This substrate hypersensitivity was evident from massive cell lysis and loss of viability. During prolonged cultivation at a fixed specific growth rate, the affinity for the growth-limiting nutrient (i.e., maltose) increased, as evident from a decreasing residual maltose concentration. Furthermore, the capacity of maltose-dependent proton uptake increased up to 2.5-fold during prolonged cultivation. Genome-wide transcriptome analysis showed that the increased maltose transport capacity was not primarily due to increased transcript levels of maltose-permease genes upon prolonged cultivation. We propose that selection for improved substrate affinity (ratio of maximum substrate consumption rate and substrate saturation constant) in maltose-limited cultures leads to selection for cells with an increased capacity for maltose uptake. At the same time, the accumulative nature of maltose-proton symport in S. cerevisiae leads to unrestricted uptake when maltose-adapted cells are exposed to a substrate excess. These changes were retained after isolation of individual cell lines from the chemostat cultures and nonselective cultivation, indicating that mutations were involved. The observed trade-off between substrate affinity and substrate tolerance may be relevant for metabolic engineering and strain selection for utilization of substrates that are taken up by proton symport.
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Affiliation(s)
- Mickel L A Jansen
- Department of Biotechnology, Delft University of Technology, 2628 BC Delft, The Netherlands
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11
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Alves-Araújo C, Hernandez-Lopez MJ, Sousa MJ, Prieto JA, Randez-Gil F. Cloning and characterization of the MAL11 gene encoding a high-affinity maltose transporter from Torulaspora delbrueckii. FEMS Yeast Res 2004; 4:467-76. [PMID: 14734027 DOI: 10.1016/s1567-1356(03)00208-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The transport and regulation of maltose utilization by Torulaspora delbrueckii, one of the most abundant non-Saccharomyces species present in home-made corn and rye bread dough, has been investigated. A DNA fragment containing the MAL11 gene from T. delbrueckii (TdMAL11) was isolated by complementation cloning in Saccharomyces cerevisiae. DNA sequence analysis revealed the presence of an open reading frame (ORF) of 1884 bp, encoding a 627-amino acid membrane protein, which displays high homology to other yeast maltose transporters. Upstream of TdMAL11, the DNA insert contained a partial ORF (TdMAL12) on the opposite strand, which showed high similarity to the S. cerevisiae MAL12 gene. Sequence analysis, Northern blot and transport measurements indicated that TdMAL11 expression is regulated by the carbon source. Attempts to disrupt TdMAL11 revealed the presence of two functional MAL loci. Disruption of a single copy decreased the V(max) of maltose transport, but not the K(m), whereas the double disruption abolished the uptake of this sugar in T. delbrueckii.
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Affiliation(s)
- Cecília Alves-Araújo
- Department of Biology, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal
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12
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Omura F, Kodama Y. The N-terminal domain of yeast Bap2 permease is phosphorylated dependently on the Npr1 kinase in response to starvation. FEMS Microbiol Lett 2004; 230:227-34. [PMID: 14757244 DOI: 10.1016/s0378-1097(03)00918-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
The Saccharomyces cerevisiae branched-chain amino acid permease Bap2p plays a major role in leucine, isoleucine, and valine transport, and its synthesis is regulated transcriptionally. Bap2p undergoes a starvation-induced degradation depending upon ubiquitination and the functions of N- and C-terminal domains of Bap2p. Here we show that the N-terminal domain of Bap2p is phosphorylated in response to rapamycin treatment when both the N- and C-termini of Bap2p are fused to glutathione S-transferase. The phosphorylation is dependent on Ser/Thr kinase Npr1p. In npr1 cells, Bap2p becomes slightly more susceptible to the rapamycin-induced degradation, suggesting that Npr1p counteracts the degradation system for Bap2p.
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Affiliation(s)
- Fumihiko Omura
- Institute for Beer and RTD Development, Suntory Limited, 1-1-1, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka 618-8503, Japan.
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13
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Membrane trafficking of yeast transporters: mechanisms and physiological control of downregulation. MOLECULAR MECHANISMS CONTROLLING TRANSMEMBRANE TRANSPORT 2004. [DOI: 10.1007/b97215] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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14
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Horák J. The role of ubiquitin in down-regulation and intracellular sorting of membrane proteins: insights from yeast. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1614:139-55. [PMID: 12896807 DOI: 10.1016/s0005-2736(03)00195-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Ubiquitination is a versatile tool used by all eukaryotic organisms for controlling the stability, function, and intracellular localization of a wide variety of proteins. Two of the best characterized functions of protein ubiquitination are to mark proteins for degradation by cytosolic proteasome and to promote the internalization of certain plasma membrane proteins via the endocytotic pathway, followed by their degradation in the vacuole. Recent studies of membrane proteins both in yeast and mammalian cells suggest that the role of ubiquitin may extend beyond its function as an internalization signal in that it also may be required for modification of some component(s) of the endocytotic machinery, and for cargo protein sorting at the late endosome and the Golgi apparatus level. In this review, I will attempt to bring together what is currently known about the role of ubiquitination in controlling protein trafficking between the yeast plasma membrane, the trans-Golgi network, and the vacuole/lysosome.
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Affiliation(s)
- Jaroslav Horák
- Department of Membrane Transport, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, 142 20 Prague, Czech Republic.
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15
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Winderickx J, Holsbeeks I, Lagatie O, Giots F, Thevelein J, de Winde H. From feast to famine; adaptation to nutrient availability in yeast. ACTA ACUST UNITED AC 2002. [DOI: 10.1007/3-540-45611-2_7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/14/2023]
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16
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Jansen MLA, De Winde JH, Pronk JT. Hxt-carrier-mediated glucose efflux upon exposure of Saccharomyces cerevisiae to excess maltose. Appl Environ Microbiol 2002; 68:4259-65. [PMID: 12200274 PMCID: PMC124116 DOI: 10.1128/aem.68.9.4259-4265.2002] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2002] [Accepted: 06/18/2002] [Indexed: 11/20/2022] Open
Abstract
When wild-type Saccharomyces cerevisiae strains pregrown in maltose-limited chemostat cultures were exposed to excess maltose, release of glucose into the external medium was observed. Control experiments confirmed that glucose release was not caused by cell lysis or extracellular maltose hydrolysis. To test the hypothesis that glucose efflux involved plasma membrane glucose transporters, experiments were performed with an S. cerevisiae strain in which all members of the hexose transporter (HXT) gene family had been eliminated and with an isogenic reference strain. Glucose efflux was virtually eliminated in the hexose-transport-deficient strain. This constitutes experimental proof that Hxt transporters facilitate export of glucose from S. cerevisiae cells. After exposure of the hexose-transport-deficient strain to excess maltose, an increase in the intracellular glucose level was observed, while the concentrations of glucose 6-phosphate and ATP remained relatively low. These results demonstrate that glucose efflux can occur as a result of uncoordinated expression of the initial steps of maltose metabolism and the subsequent reactions in glucose dissimilation. This is a relevant phenomenon for selection of maltose-constitutive strains for baking and brewing.
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Affiliation(s)
- Mickel L A Jansen
- Kluyver Laboratory of Biotechnology, Delft University of Technology, 2628 BC Delft, The Netherlands
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Fraser JA, Davis MA, Hynes MJ. The genes gmdA, encoding an amidase, and bzuA, encoding a cytochrome P450, are required for benzamide utilization in Aspergillus nidulans. Fungal Genet Biol 2002; 35:135-46. [PMID: 11848676 DOI: 10.1006/fgbi.2001.1307] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Two unlinked loci, gmdA and bzuA, have previously been identified as being required for the utilization of benzamide as the sole nitrogen source by Aspergillus nidulans. We have cloned each of these genes via direct complementation. The gmdA gene encodes a predicted product belonging to the amidase signature sequence family that displays similarity to AmdS from A. nidulans. However, identity is significantly higher to the amdS gene from Aspergillus niger. The bzuA gene encodes a protein belonging to the cytochrome P450 superfamily and is orthologous to the benzoate para-hydroxylase-encoding gene bphA of A. niger. The bzuA1 mutation prevents the use of benzoate as a carbon source and intracellular accumulation of benzoate results in growth inhibition on benzamide. Northern blot analysis has shown that gmdA expression is subject solely to AreA-dependent nitrogen metabolite repression while bzuA is strongly benzoate inducible and subject to CreA-mediated carbon catabolite repression and a probable inactivation of benzoate induction by glucose. Fluorescence microscopy of a fusion of the N-terminal end of BzuA to green fluorescent protein revealed that this protein localizes to the endoplasmic reticulum.
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Affiliation(s)
- James A Fraser
- Department of Genetics, University of Melbourne, Parkville, Victoria, 3010, Australia
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18
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Krampe S, Boles E. Starvation-induced degradation of yeast hexose transporter Hxt7p is dependent on endocytosis, autophagy and the terminal sequences of the permease. FEBS Lett 2002; 513:193-6. [PMID: 11904149 DOI: 10.1016/s0014-5793(02)02297-4] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The yeast high-affinity glucose transporters Hxt6p and Hxt7p are rapidly degraded during nitrogen starvation in the presence of high concentrations of fermentable carbon sources. Our results suggest that degradation is mainly due to the stimulation of general protein turnover and not caused by a mechanism specifically triggered by glucose. Analysis of Hxt6p/7p stability and cellular distribution in end4, aut2 and apg1 mutants indicates that Hxt7p is internalized by endocytosis, and autophagy is involved in the final delivery of Hxt7p to the vacuole for proteolytic degradation. Internalization and degradation of Hxt7p were blocked after truncation of its N-terminal hydrophilic domain. Nevertheless, this fully functional and stabilized hexose transporter could not maintain fermentation capacity of the yeast cells under starvation conditions, indicating a regulatory constraint on glucose uptake.
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Affiliation(s)
- Stefanie Krampe
- Institut für Mikrobiologie, Heinrich-Heine-Universität, Universitätsstr. 1, Geb. 26.12.01, D-40225, Düsseldorf, Germany
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Lucero P, Moreno E, Lagunas R. Catabolite inactivation of the sugar transporters in Saccharomyces cerevisiae is inhibited by the presence of a nitrogen source. FEMS Yeast Res 2002; 1:307-14. [PMID: 12702334 DOI: 10.1111/j.1567-1364.2002.tb00049.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Saccharomyces cerevisiae uses glucose preferentially to any other carbon source and this preferential use is ensured by control mechanisms triggered by glucose. The consensus is that inactivation of sugar transporters other than glucose transporters is one of these mechanisms. This inactivation is called catabolite inactivation because of its apparent analogy with the catabolite inactivation of gluconeogenic enzymes. Recently, doubt has been cast on the role of the inactivation of the sugar transporters in controlling the use of glucose because this inactivation neither is specifically triggered by glucose nor specifically affects non-glucose sugar transporters. Based on the fact that this inactivation has been almost exclusively investigated using nitrogen-starved cells, it has been proposed that it might be due to the stimulation of the protein turnover that follows nitrogen starvation. The results obtained in this work support this possibility since they show that the presence of a nitrogen source in the medium strongly inhibited the inactivation. It is concluded that, in growing yeast cells, the contribution of the inactivation by glucose of the non-glucose sugar transporters to the preferential use of glucose is much lower than generally believed.
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Affiliation(s)
- Pilar Lucero
- Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Arturo Duperier, 4, 28029 Madrid, Spain
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20
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Omura F, Kodama Y, Ashikari T. The N-terminal domain of the yeast permease Bap2p plays a role in its degradation. Biochem Biophys Res Commun 2001; 287:1045-50. [PMID: 11587526 DOI: 10.1006/bbrc.2001.5697] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The amino acid permease Bap2p in Saccharomyces cerevisiae mediates a major part of the uptake of leucine, isoleucine, and valine from media containing a preferred nitrogen source. Although the transcriptional controls of BAP2 have been well studied, the posttranslational down-regulation mechanisms for Bap2p have not been established. Here we show that Bap2p is subject to a starvation-induced degradation upon rapamycin treatment or cultivation with proline as the sole nitrogen source. The starvation-induced degradation of Bap2p was dependent on the cellular functions of ubiquitination and endocytosis. Down-regulation of the permease required the most probable ubiquitination sites, the lysine residues situated in the N-terminal 49 residues, as well as the C-terminal domain. Furthermore, when the N-terminal domain of Bap2p was fused to the general amino acid permease Gap1p, the resultant chimeric permease became susceptible to the starvation-induced degradation, indicating that the Bap2p N-terminus contains a determinant responsive to the starvation signals.
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Affiliation(s)
- F Omura
- Institute for Fundamental Research, Suntory Ltd., 1-1-1, Wakayamadai, Shimamoto-cho, Mishima-gun, Osaka, 618-8503, Japan.
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21
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Omura F, Kodama Y, Ashikari T. The basal turnover of yeast branched-chain amino acid permease Bap2p requires its C-terminal tail. FEMS Microbiol Lett 2001; 194:207-14. [PMID: 11164310 DOI: 10.1111/j.1574-6968.2001.tb09471.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The branched-chain amino acid permease Bap2p is a transport system for leucine, isoleucine, and valine in Saccharomyces cerevisiae, and its synthesis is regulated transcriptionally. However, the downregulation mechanisms of Bap2p have not been established. Here we demonstrate that the C-terminal region of Bap2p plays a pivotal role in its basal turnover. Truncation of the C-terminal 29 residues caused the stabilization and accumulation in the plasma membrane of Bap2p. Furthermore, when the Bap2p C-terminal region was fused to green fluorescent protein, the fusion protein localized to the plasma membrane, suggesting the existence of a possible degradation-related acceptor site for the C-terminal tail of Bap2p.
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Affiliation(s)
- F Omura
- Institute for Fundamental Research, Suntory Ltd., 1-1-1, Wakayamadai, Shimamoto-cho, Mishima-gun, 618-8503, Osaka, Japan.
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22
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van Hoek P, de Hulster E, van Dijken JP, Pronk JT. Fermentative capacity in high-cell-density fed-batch cultures of baker's yeast. Biotechnol Bioeng 2000. [DOI: 10.1002/(sici)1097-0290(20000605)68:5<517::aid-bit5>3.0.co;2-o] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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23
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Medintz I, Wang X, Hradek T, Michels CA. A PEST-like sequence in the N-terminal cytoplasmic domain of Saccharomyces maltose permease is required for glucose-induced proteolysis and rapid inactivation of transport activity. Biochemistry 2000; 39:4518-26. [PMID: 10758001 DOI: 10.1021/bi992455a] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Maltose permease is required for maltose transport into Saccharomyces cells. Glucose addition to maltose-fermenting cells causes selective delivery of this integral plasma membrane protein to the yeast vacuole via endocytosis for degradation by resident proteases. This glucose-induced degradation is independent of the proteasome but requires ubiquitin and certain ubiquitin conjugating enzymes. We used mutation analysis to identify target sequences in Mal61/HA maltose permease involved in its selective glucose-induced degradation. A nonsense mutation was introduced at codon 581, creating a truncated functional maltose permease. Additional missense mutations were introduced into the mal61/HA-581NS allele, altering potential phosphorylation and ubiquitination sites. No significant effect was seen on the rate of glucose-induced degradation of these mutant proteins. Deletion mutations were constructed, removing residues 2-30, 31-60, 61-90, and 49-78 of the N-terminal cytoplasmic domain, as well as a missense mutation of a dileucine motif. Results indicate that the proline-, glutamate-, aspartate-, serine-, and threonine-rich (PEST) sequence found in the N-terminal cytoplasmic domain, particularly residues 49-78, is required for glucose-induced degradation of Mal61/HAp and for the rapid glucose-induced inactivation of maltose transport activity. The decreased rate of glucose-induced degradation correlates with a decrease in the level of glucose-induced ubiquitination of the DeltaPEST mutant permease. In addition, newly synthesized mutant permease proteins lacking residues 49-78 or carrying an alteration in the dileucine motif, residues 69 and 70, are resistant to glucose-induced inactivation of maltose transport activity. This N-terminal PEST-like sequence is the target of both the Rgt2p-dependent and the Glc7p-Reg1p-dependent glucose signaling pathways.
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Affiliation(s)
- I Medintz
- Biology Department, Queens College and the Graduate School of the City University of New York, 65-30 Kissena Boulevard, Flushing, New York 11367, USA
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Petersson J, Pattison J, Kruckeberg AL, Berden JA, Persson BL. Intracellular localization of an active green fluorescent protein-tagged Pho84 phosphate permease in Saccharomyces cerevisiae. FEBS Lett 1999; 462:37-42. [PMID: 10580087 DOI: 10.1016/s0014-5793(99)01471-4] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Green fluorescent protein (GFP) from Aequorea victoria was used as an in vivo reporter protein when fused to the carboxy-terminus of the Pho84 phosphate permease of Saccharomyces cerevisiae. Both components of the fusion protein displayed their native functions and revealed a cellular localization and degradation of the Pho84-GFP chimera consistent with the behavior of the wild-type Pho84 protein. The GFP-tagged chimera allowed for a detection of conditions under which the Pho84 transporter is localized to its functional environment, i.e. the plasma membrane, and conditions linked to relocation of the protein to the vacuole for degradation. By use of the methodology described, GFP should be useful in studies of localization and degradation also of other membrane proteins in vivo.
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Affiliation(s)
- J Petersson
- Department of Engineering and Natural Sciences, Växjö University, 351 95, Växjö, Sweden
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