Functional characterization of a xylose transporter in Aspergillus nidulans

In a previous study, alcS, a gene of the Aspergillus nidulans alc cluster, was shown to encode a protein that belongs to the GPR1/FUN34/YaaH membrane protein family. BLAST screening of the A. nidulans genome data identified additional genes encoding hypothetical proteins that could belong to this family. In this study we report the functional characterization of one of them, AN5226. Its expression is induced by ethanol and ethyl acetate (two inducers of the alc genes) and is mediated by the specific transcriptional activator of genes of the acetate-utilization pathway FacB. Growth of a null mutant (ΔAN5226) is notably affected when acetate is used as sole carbon source at low concentration and in a high pH medium, i.e. when protonated acetate, the form that can enter the cell by passive diffusion, is present in low amounts. Consistently, expression of AN5226 is also induced by acetate, but only when the latter is present at low concentrations. 14C-labelled acetate uptake experiments using germinating conidia demonstrate an essential role for AN5226 in mediated acetate transport. To our knowledge this report is the first to provide evidence for the identification of an acetate transporter in filamentous fungi. We have designated AN5226 as acpA (for acetate permease A).

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Functional characterization of the putative Aspergillus nidulans DNA damage binding protein homologue DdbA

Molecular Genetics and Genomics ◽

10.1007/s00438-007-0307-0 ◽

2007 ◽

Vol 279 (3) ◽

pp. 239-253 ◽

Cited By ~ 2

Author(s):

Joel Fernandes Lima ◽

Iran Malavazi ◽

Márcia Eliana da Silva Ferreira ◽

Marcela Savoldi ◽

André Oliveira Mota ◽

...

Keyword(s):

Dna Damage ◽

Aspergillus Nidulans ◽

Binding Protein ◽

Functional Characterization

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Identification of members of the Aspergillus nidulans SREA regulon: genes involved in siderophore biosynthesis and utilization

Biochemical Society Transactions ◽

10.1042/bst0300781 ◽

2002 ◽

Vol 30 (4) ◽

pp. 781-783 ◽

Cited By ~ 41

Author(s):

H. Oberegger ◽

I. Zadra ◽

M. Schoeser ◽

B. Abt ◽

W. Parson ◽

...

Keyword(s):

Aspergillus Nidulans ◽

Functional Characterization ◽

Primary Control ◽

Siderophore Biosynthesis ◽

Iron Supply ◽

Potential Impact ◽

Almost All ◽

Transcriptional Induction ◽

Insight Into

Iron is an essential trace element for almost all organisms. However, an excess of this metal within cells can be deleterious on account of catalysis of cell-damaging hydroxyl radicals. Therefore, the concentration of iron within cells is tightly regulated and the primary control occurs by regulating its uptake. Under conditions of low iron availability, most fungi mobilize extracellular iron by excretion of low-molecular-mass ferric iron chelators, termed siderophores. Due to the potential impact of iron metabolism on fungal pathogenicity, a better insight into siderophore-mediated iron uptake is needed. In Aspergillus nidulans, siderophore biosynthesis and uptake are negatively regulated by the GATA-type transcription factor SREA. Hence, genes involved in siderophore biosynthesis and uptake are characterized by transcriptional induction under iron limitation in wild-type strain and de-repression in an sreA-deletion strain under conditions of sufficient iron supply. Such genes have been searched for using different strategies, e.g. differential mRNA display and expression analysis of candidate genes from various A. nidulans sequence databases. The identified genes presumably encode enzymes needed for siderophore biosynthesis, and transporters involved in siderophore uptake and/or excretion. The functional characterization of these genes will help to unravel the pathways involved in siderophore biosynthesis and uptake.

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Functional Characterization of a Maize Purine Transporter by Expression in Aspergillus nidulans

The Plant Cell ◽

10.1105/tpc.13.4.953 ◽

2001 ◽

Vol 13 (4) ◽

pp. 953-964 ◽

Cited By ~ 50

Author(s):

Eleftheria Argyrou ◽

Vicky Sophianopoulou ◽

Neil Schultes ◽

George Diallinas

Keyword(s):

Aspergillus Nidulans ◽

Functional Characterization ◽

Purine Transporter

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Functional Characterization of a Maize Purine Transporter by Expression in Aspergillus nidulans

The Plant Cell ◽

10.2307/3871352 ◽

2001 ◽

Vol 13 (4) ◽

pp. 953

Author(s):

Eleftheria Argyrou ◽

Vicky Sophianopoulou ◽

Neil Schultes ◽

George Diallinas

Keyword(s):

Aspergillus Nidulans ◽

Functional Characterization ◽

Purine Transporter

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Functional Characterization of Aspergillus nidulans ypkA, a Homologue of the Mammalian Kinase SGK

PLoS ONE ◽

10.1371/journal.pone.0057630 ◽

2013 ◽

Vol 8 (3) ◽

pp. e57630 ◽

Cited By ~ 14

Author(s):

Ana Cristina Colabardini ◽

Neil Andrew Brown ◽

Marcela Savoldi ◽

Maria Helena S. Goldman ◽

Gustavo Henrique Goldman

Keyword(s):

Aspergillus Nidulans ◽

Functional Characterization

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Functional characterization of a highly specific l-arabinose transporter from Trichoderma reesei

Microbial Cell Factories ◽

10.1186/s12934-021-01666-4 ◽

2021 ◽

Vol 20 (1) ◽

Author(s):

Sami Havukainen ◽

Jonai Pujol-Giménez ◽

Mari Valkonen ◽

Matthias A. Hediger ◽

Christopher P. Landowski

Keyword(s):

Trichoderma Reesei ◽

Soluble Sugars ◽

Functional Characterization ◽

Value Added ◽

High Specificity ◽

Biofuel Production ◽

Primary Metabolism ◽

High Affinity ◽

Xylose Transporter

Abstract Background Lignocellulose biomass has been investigated as a feedstock for second generation biofuels and other value-added products. Some of the processes for biofuel production utilize cellulases and hemicellulases to convert the lignocellulosic biomass into a range of soluble sugars before fermentation with microorganisms such as yeast Saccharomyces cerevisiae. One of these sugars is l-arabinose, which cannot be utilized naturally by yeast. The first step in l-arabinose catabolism is its transport into the cells, and yeast lacks a specific transporter, which could perform this task. Results We identified Trire2_104072 of Trichoderma reesei as a potential l-arabinose transporter based on its expression profile. This transporter was described already in 2007 as d-xylose transporter XLT1. Electrophysiology experiments with Xenopus laevis oocytes and heterologous expression in yeast revealed that Trire2_104072 is a high-affinity l-arabinose symporter with a Km value in the range of $$\sim$$ ∼ 0.1–0.2 mM. It can also transport d-xylose but with low affinity (Km$$\sim$$ ∼ 9 mM). In yeast, l-arabinose transport was inhibited slightly by d-xylose but not by d-glucose in an assay with fivefold excess of the inhibiting sugar. Comparison with known l-arabinose transporters revealed that the expression of Trire2_104072 enabled yeast to uptake l-arabinose at the highest rate in conditions with low extracellular l-arabinose concentration. Despite the high specificity of Trire2_104072 for l-arabinose, the growth of its T. reesei deletion mutant was only affected at low l-arabinose concentrations. Conclusions Due to its high affinity for l-arabinose and low inhibition by d-glucose or d-xylose, Trire2_104072 could serve as a good candidate for improving the existing pentose-utilizing yeast strains. The discovery of a highly specific l-arabinose transporter also adds to our knowledge of the primary metabolism of T. reesei. The phenotype of the deletion strain suggests the involvement of other transporters in l-arabinose transport in this species.

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