scholarly journals Aspergillus niger mstA encodes a high-affinity sugar/H+ symporter which is regulated in response to extracellular pH

2004 ◽  
Vol 379 (2) ◽  
pp. 375-383 ◽  
Author(s):  
Patricia A. vanKUYK ◽  
Jasper A. DIDERICH ◽  
Andrew P. MacCABE ◽  
Oscar HERERRO ◽  
George J. G. RUIJTER ◽  
...  
Keyword(s):  
Aspergillus Niger ◽  
Ph Regulation ◽  
Functional Characterization ◽  
Carbon Sources ◽  
Sugar Transport ◽  
Major Facilitator Superfamily ◽  
Northern Analysis ◽  
High Affinity ◽  
Hexose Uptake ◽  
Major Facilitator

A sugar-transporter-encoding gene, mstA, which is a member of the major facilitator superfamily, has been cloned from a genomic DNA library of the filamentous fungus Aspergillus niger. To enable the functional characterization of MSTA, a full-length cDNA was expressed in a Saccharomyces cerevisiae strain deficient in hexose uptake. Uptake experiments using 14C-labelled monosaccharides demonstrated that although able to transport d-fructose (Km, 4.5±1.0 mM), d-xylose (Km, 0.3±0.1 mM) and d-mannose (Km, 60±20 µM), MSTA has a preference for d-glucose (Km, 25±10 µM). pH changes associated with sugar transport indicate that MSTA catalyses monosaccharide/H+ symport. Expression of mstA in response to carbon starvation and upon transfer to poor carbon sources is consistent with a role for MSTA as a high-affinity transporter for d-glucose, d-mannose and d-xylose. Northern analysis has shown that mstA is subject to CreA-mediated carbon catabolite repression and pH regulation mediated by PacC. A. niger strains in which the mstA gene had been disrupted are phenotypically identical with isogenic reference strains when grown on 0.1–60 mM d-glucose, d-mannose, d-fructose or d-xylose. This indicates that A. niger possesses other transporters capable of compensating for the absence of MSTA.

scholarly journals Genome-wide identification and analyses of tomato (Solanum lycopersicum L.) high-affinity nitrate transporter 2 (NRT2) family genes and their responses to drought and salinity

2021 ◽  
Author(s):  
M. AYDIN AKBUDAK ◽  
Ertugrul Filiz ◽  
Durmus Cetin
Keyword(s):  
Solanum Lycopersicum ◽  
Expression Profiles ◽  
Gene Families ◽  
Major Facilitator Superfamily ◽  
Nitrate Transporter ◽  
Tomato Genome ◽  
High Affinity ◽  
Solanum Lycopersicum L ◽  
Major Facilitator ◽  
Systematic Identification

High-affinity nitrate transporter 2 (NRT2) proteins have vital roles in nitrate (NO3-) uptake and translocation in plants. The gene families coding NRT2 proteins have been identified and functionally characterized in many plant species. However, no systematic identification of NRT2 family members have been reported in tomato (Solanum lycopersicum). There is also little known about their expression profiles under environmental stresses. Accordingly, the present study aimed to identify NRT2 gene family in the tomato genome; then, investigate them in detail through bioinformatics, physiological and expression analyses. As a result, four novel NRT2 genes were identified in the tomato genome, all of which contain the same domain belonging to the Major Facilitator Superfamily (PF07690). The co-expression network of SlNRT genes revealed that they were co-expressed with several other genes in many different molecular pathways including transport, photosynthesis, fatty acid metabolism and amino acid catabolism. Programming many crucial physiological and metabolic pathways, various numbers of phosphorylation sites were predicted in the NRT2 proteins.

Identification and functional characterization of Penicillium marneffei major facilitator superfamily (MFS) transporters

2020 ◽  
Vol 84 (7) ◽  
pp. 1373-1383
Author(s):  
Setyowati T. Utami ◽  
Carissa I. Indriani ◽  
Anom Bowolaksono ◽  
Takashi Yaguchi ◽  
Xinyue Chen ◽  
...  
Keyword(s):  
Functional Characterization ◽  
Major Facilitator Superfamily ◽  
Penicillium Marneffei ◽  
Major Facilitator ◽  
Mfs Transporters

scholarly journals In Silico and Transcriptional Analysis of Carbohydrate Uptake Systems of Streptomyces coelicolor A3(2)

2004 ◽  
Vol 186 (5) ◽  
pp. 1362-1373 ◽  
Author(s):  
Ralph Bertram ◽  
Maximilian Schlicht ◽  
Kerstin Mahr ◽  
Harald Nothaft ◽  
Milton H. Saier ◽  
...  
Keyword(s):  
Antibiotic Production ◽  
Streptomyces Coelicolor ◽  
Essential Feature ◽  
Carbon Sources ◽  
Gene Clusters ◽  
Major Facilitator Superfamily ◽  
Transcriptional Analysis ◽  
Phosphotransferase System ◽  
Function Similarity ◽  
Major Facilitator

ABSTRACT Streptomyces coelicolor is the prototype for the investigation of antibiotic-producing and differentiating actinomycetes. As soil bacteria, streptomycetes can metabolize a wide variety of carbon sources and are hence vested with various specific permeases. Their activity and regulation substantially determine the nutritional state of the cell and, therefore, influence morphogenesis and antibiotic production. We have surveyed the genome of S. coelicolor A3(2) to provide a thorough description of the carbohydrate uptake systems. Among 81 ATP-binding cassette (ABC) permeases that are present in the genome, we found 45 to encode a putative solute binding protein, an essential feature for carbohydrate permease function. Similarity analysis allowed the prediction of putative ABC systems for transport of cellobiose and cellotriose, α-glucosides, lactose, maltose, maltodextrins, ribose, sugar alcohols, xylose, and β-xylosides. A novel putative bifunctional protein composed of a substrate binding and a membrane-spanning moiety is likely to account for ribose or ribonucleoside uptake. Glucose may be incorporated by a proton-driven symporter of the major facilitator superfamily while a putative sodium-dependent permease of the solute-sodium symporter family may mediate uptake of galactose and a facilitator protein of the major intrinsic protein family may internalize glycerol. Of the predicted gene clusters, reverse transcriptase PCRs showed active gene expression in 8 of 11 systems. Together with the previously surveyed permeases of the phosphotransferase system that accounts for the uptake of fructose and N-acetylglucosamine, the genome of S. coelicolor encodes at least 53 potential carbohydrate uptake systems.

scholarly journals The Major Facilitator Superfamily-Type Transporter YmfE and the Multidrug-Efflux Activator Mta Mediate Bacillibactin Secretion in Bacillus subtilis

2008 ◽  
Vol 190 (15) ◽  
pp. 5143-5152 ◽  
Author(s):  
Marcus Miethke ◽  
Sarah Schmidt ◽  
Mohamed A. Marahiel
Keyword(s):  
Bacillus Subtilis ◽  
Iron Acquisition ◽  
Transcriptional Regulator ◽  
Major Facilitator Superfamily ◽  
Second Step ◽  
Mutant Library ◽  
Multidrug Efflux ◽  
High Affinity ◽  
Regulatory Aspect ◽  
Major Facilitator

ABSTRACT High-affinity iron acquisition in Bacillus subtilis is mediated via the bacillibactin catechole siderophore pathway. Three of the four essential pathway steps, bacillibactin synthesis, Fe-bacillibactin uptake, and Fe-bacillibactin hydrolysis have been characterized previously. The functional and regulatory components for bacillibactin secretion, the second step of the siderophore pathway, remained unknown. In this study, the screening of a B. subtilis exporter mutant library led to the identification of the YmfE major facilitator superfamily (MFS)-type transporter as a target for bacillibactin export. Analysis of iron-limited ymfE mutant cultures displayed an eightfold reduced bacillibactin secretion and, on the other hand, a 25-fold increased secretion of the bacillibactin precursor 2,3-dihydroxybenzoate. Investigation of the regulatory aspect revealed that bacillibactin secretion is, in contrast to all other components of the pathway, independent of the ferric uptake repressor Fur. Indeed, the MerR-type transcriptional regulator Mta was found to activate both bacillibactin secretion and ymfE gene expression, exposing Mta as an additional regulatory member of the bacillibactin pathway.

scholarly journals Transmembrane segments 1, 5, 7 and 8 are required for high-affinity glucose transport by Saccharomyces cerevisiae Hxt2 transporter

2003 ◽  
Vol 372 (1) ◽  
pp. 247-252 ◽  
Author(s):  
Toshiko KASAHARA ◽  
Michihiro KASAHARA
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Glucose Transport ◽  
Glucose Transporter ◽  
Amino Acid Identity ◽  
Major Facilitator Superfamily ◽  
Transport Activity ◽  
Transmembrane Segments ◽  
High Affinity ◽  
Yeast Transformants ◽  
Major Facilitator

Hxt2 is a high-affinity facilitative glucose transporter of Saccharomyces cerevisiae and belongs to the major facilitator superfamily. Hxt1 shares ≈ 70% amino acid identity with Hxt2 in its transmembrane segments (TMs) and inter-TM loops, but transports d-glucose with an affinity about one-tenth of that of Hxt2. To determine which TMs of Hxt2 are important for high-affinity glucose transport, we constructed chimaeras of Hxt2 and Hxt1 by randomly replacing each of the 12 TMs of Hxt2 with the corresponding segment of Hxt1, for a total of 4096 different transporters. Among > 20000 yeast transformants screened, 39 different clones were selected by plate assays of high-affinity glucose-transport activity and sequenced. With only two exceptions, the selected chimaeras contained Hxt2 TMs 1, 5, 7 and 8. We then constructed chimaeras corresponding to all 16 possible combinations of Hxt2 TMs 1, 5, 7 and 8. Only one chimaera, namely that containing all four Hxt2 TMs, exhibited transport activity comparable with that of Hxt2. The Km and Vmax values for d-glucose transport, and the substrate specificity of this chimaera were almost identical with those of Hxt2. These results indicate that TMs 1, 5, 7 and 8 are necessary for exhibiting high-affinity glucose-transport activity of Hxt2.

scholarly journals Genome-Wide Analysis of Sugar Transporters Identifies the gtsA Gene for Glucose Transportation in Pseudomonas stutzeri A1501

2020 ◽  
Vol 8 (4) ◽  
pp. 592
Author(s):  
Yaqun Liu ◽  
Liguo Shang ◽  
Yuhua Zhan ◽  
Min Lin ◽  
Zhu Liu ◽  
...  
Keyword(s):  
Gene Diversity ◽  
Carbon Sources ◽  
Sugar Transport ◽  
Genomic Analysis ◽  
Pseudomonas Stutzeri ◽  
Major Facilitator Superfamily ◽  
Transport Systems ◽  
Phosphotransferase System ◽  
Metabolic System ◽  
Sugar Transporters

Pseudomonas stutzeri A1501 possesses an extraordinary number of transporters which confer this rhizosphere bacterium with the sophisticated ability to metabolize various carbon sources. However, sugars are not a preferred carbon source for P. stutzeri A1501. The P. stutzeri A1501 genome has been sequenced, allowing for the homology-based in silico identification of genes potentially encoding sugar-transport systems by using established microbial sugar transporters as a template sequence. Genomic analysis revealed that there were 10 sugar transporters in P. stutzeri A1501, most of which belong to the ATP-binding cassette (ABC) family (5/10); the others belong to the phosphotransferase system (PTS), major intrinsic protein (MIP) family, major facilitator superfamily (MFS) and the sodium solute superfamily (SSS). These systems might serve for the import of glucose, galactose, fructose and other types of sugar. Growth analysis showed that the only effective medium was glucose and its corresponding metabolic system was relatively complete. Notably, the loci of glucose metabolism regulatory systems HexR, GltR/GtrS, and GntR were adjacent to the transporters ABCMalEFGK, ABCGtsABCD, and ABCMtlEFGK, respectively. Only the ABCGtsABCD expression was significantly upregulated under both glucose-sufficient and -limited conditions. The predicted structure and mutant phenotype data of the key protein GtsA provided biochemical evidence that P. stutzeri A1501 predominantly utilized the ABCGtsABCD transporter for glucose uptake. We speculate that gene absence and gene diversity in P. stutzeri A1501 was caused by sugar-deficient environmental factors and hope that this report can provide guidance for further analysis of similar bacterial lifestyles.

scholarly journals CgMFS1, a Major Facilitator Superfamily Transporter, Is Required for Sugar Transport, Oxidative Stress Resistance, and Pathogenicity of Colletotrichum gloeosporioides from Hevea brasiliensis

2021 ◽  
Vol 43 (3) ◽  
pp. 1548-1557
Author(s):  
Na Liu ◽  
Qiannan Wang ◽  
Chaozu He ◽  
Bang An
Keyword(s):  
Oxidative Stress ◽  
Hevea Brasiliensis ◽  
Fungicide Resistance ◽  
Molecular Mechanisms ◽  
Colletotrichum Gloeosporioides ◽  
3D Structure ◽  
Sugar Transport ◽  
Major Facilitator Superfamily ◽  
Diverse Range ◽  
Major Facilitator

Colletotrichum gloeosporioides is the main causal agent of anthracnose in various plant species. Determining the molecular mechanisms underlying the pathogenicity and fungicide resistance of C. gloeosporioides could help build new strategies for disease control. The major facilitator superfamily (MFS) has multiple roles in the transport of a diverse range of substrates. In the present study, an MFS protein CgMFS1 was characterized in C. gloeosporioides. This protein contains seven transmembrane domains, and its predicted 3D structure is highly similar to the reported hexose transporters. To investigate the biological functions of CgMFS1, the gene knock-out mutant ΔCgMFS1 was constructed. A colony growth assay showed that the mutant was remarkably decreased in vegetative growth in minimal medium supplemented with monosaccharides and oligosaccharides as the sole carbon sources, whereas it showed a similar growth rate and colony morphology as wild types when using soluble starch as the carbon source. A stress assay revealed that CgMFS1 is involved in oxidative stress but not in the fungicide resistance of C. gloeosporioides. Furthermore, its pathogenicity was significantly impaired in the mutant, although its appressorium formation was not affected. Our results demonstrate that CgMFS1 is required for sugar transport, resistance to oxidative stress, and the pathogenicity of Colletotrichum gloeosporioides from Hevea brasiliensis.

scholarly journals Improving citric acid production of an industrial Aspergillus niger CGMCC 10142: identification and overexpression of a high-affinity glucose transporter with different promoters

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Xianli Xue ◽  
Futi Bi ◽  
Boya Liu ◽  
Jie Li ◽  
Lan Zhang ◽  
...  
Keyword(s):  
Citric Acid ◽  
Aspergillus Niger ◽  
Acid Production ◽  
Glucose Transporter ◽  
Citrate Synthase ◽  
Sugar Content ◽  
Sugar Transport ◽  
Citric Acid Production ◽  
Utilization Rate ◽  
High Affinity

Abstract Background Glucose transporters play an important role in the fermentation of citric acid. In this study, a high-affinity glucose transporter (HGT1) was identified and overexpressed in the industrial strain A. niger CGMCC 10142. HGT1-overexpressing strains using the PglaA and Paox1 promoters were constructed to verify the glucose transporter functions. Result As hypothesized, the HGT1-overexpressing strains showed higher citric acid production and lower residual sugar contents. The best-performing strain A. niger 20-15 exhibited a reduction of the total sugar content and residual reducing sugars by 16.5 and 44.7%, while the final citric acid production was significantly increased to 174.1 g/L, representing a 7.3% increase compared to A. niger CGMCC 10142. Measurement of the mRNA expression levels of relevant genes at different time-points during the fermentation indicated that in addition to HGT1, citrate synthase and glucokinase were also expressed at higher levels in the overexpression strains. Conclusion The results indicate that HGT1 overexpression resolved the metabolic bottleneck caused by insufficient sugar transport and thereby improved the sugar utilization rate. This study demonstrates the usefulness of the high-affinity glucose transporter HGT1 for improving the citric acid fermentation process of Aspergillus niger CGMCC 10142.

scholarly journals Evidence of Evolutionary Conservation of Function between the Thyroxine Transporter Oatp1c1 and Major Facilitator Superfamily Members

Endocrinology ◽  
2010 ◽  
Vol 151 (12) ◽  
pp. 5941-5951 ◽  
Author(s):  
Daniel E. Westholm ◽  
Jacob D. Marold ◽  
Kevin J. Viken ◽  
Alicia H. Duerst ◽  
Grant W. Anderson ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Amino Acid ◽  
Substrate Binding ◽  
Evolutionary Conservation ◽  
Major Facilitator Superfamily ◽  
Transport Activity ◽  
Wild Type ◽  
Michaelis Constant ◽  
High Affinity ◽  
Major Facilitator

Organic anion transporting polypeptide 1c1 (Oatp1c1) is a high-affinity T4 transporter expressed in brain barrier cells. To identify Oatp1c1 amino acid residues critical for T4 transport, consensus membrane topology was predicted and a three-dimensional Oatp1c1 structure was generated using the known structures of major facilitator superfamily (MFS) transporters, glycerol 3-phosphate transporter, lactose permease, and the multidrug transporter Escherichia coli multidrug resistance protein D as templates. A total of nine amino acid mutations were generated based on amino acid conservation, localization to putative transmembrane domains, and side chain functionality. Mutant constructs were transiently transfected into human embryonic kidney 293 cells and assessed for plasma membrane localization and the capacity to transport substrate 125I-T4. Wild-type Oatp1c1, R601S, P609A, W277A/W278A, W277F/W278F, G399A/G409A, and G399L/G409L were all expressed at the plasma membrane. Wild-type Oatp1c1 and W277F/W278F displayed biphasic T4 transport kinetics, albeit the mutant did so with an approximately 10-fold increase in high-affinity Michaelis constant. The W277A/W278A mutation abolished Oatp1c1 T4 transport. G399A/G409A and G399V/G409V mutants displayed near wild-type activity in an uptake screen but exhibited diminished T4 transport activity at high-substrate concentrations, suggesting a substrate binding site collapse or inability to convert between input and output states. Finally, transmembrane domain 11 mutants R601S and P609A displayed partial T4 transport activity with significantly reduced maximum velocities and higher Michaelis constant. Arg601 is functionally strongly conserved with members of the MFS whose structures and function have been extensively studied. These data provide the experimental foundation for mapping Oatp1c1 substrate binding sites and reveal evolutionary conservation with bacterial MFS transporter members.

Sign in / Sign up

Export Citation Format

Share Document