title: Genetic Interaction of Aspergillus nidulans galR, xlnR and araR in Regulating D-Galactose and L-Arabinose Release and Catabolism Gene Expression.
abstract: In Aspergillus nidulans, the xylanolytic regulator XlnR and the arabinanolytic regulator AraR co-regulate pentose catabolism. In nature, the pentose sugars D-xylose and L-arabinose are both main building blocks of the polysaccharide arabinoxylan. In pectin and arabinogalactan, these two monosaccharides are found in combination with D-galactose. GalR, the regulator that responds to the presence of D-galactose, regulates the D-galactose catabolic pathway. In this study we investigated the possible interaction between XlnR, AraR and GalR in pentose and/or D-galactose catabolism in A. nidulans. Growth phenotypes and metabolic gene expression profiles were studied in single, double and triple disruptant A. nidulans strains of the genes encoding these paralogous transcription factors. Our results demonstrate that AraR and XlnR not only control pentose catabolic pathway genes, but also genes of the oxido-reductive D-galactose catabolic pathway. This suggests an interaction between three transcriptional regulators in D-galactose catabolism. Conversely, GalR is not involved in regulation of pentose catabolism, but controls only genes of the oxido-reductive D-galactose catabolic pathway.
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands.
authors.forename: Joanna E
authors.initials: JE
authors.lastname: Kowalczyk
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands.|Microbiology, Utrecht University, Utrecht, the Netherlands.
authors.forename: Birgit S
authors.initials: BS
authors.lastname: Gruben
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands.|Microbiology, Utrecht University, Utrecht, the Netherlands.
authors.forename: Evy
authors.initials: E
authors.lastname: Battaglia
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands.
authors.forename: Ad
authors.initials: A
authors.lastname: Wiebenga
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands.
authors.forename: Eline
authors.initials: E
authors.lastname: Majoor
authors.affiliation: Fungal Physiology, CBS-KNAW Fungal Biodiversity Centre & Fungal Molecular Physiology, Utrecht University, Utrecht, the Netherlands.
authors.forename: Ronald P
authors.initials: RP
authors.lastname: de Vries
mesh_terms: D000595:Amino Acid Sequence; D001089:Arabinose / Q000378:metabolism; D001233:Aspergillus nidulans / Q000235:genetics* / Q000378:metabolism; D004843:Epistasis, Genetic; D029968:Escherichia coli Proteins / Q000235:genetics* / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D005690:Galactose / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D008969:Molecular Sequence Data; D010641:Phenotype; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D015534:Trans-Activators / Q000235:genetics* / Q000378:metabolism; D014994:Xylose / Q000378:metabolism
chemical_list: D029968:Escherichia coli Proteins; D005656:Fungal Proteins; C050993:Galactose repressor proteins; D012097:Repressor Proteins; D015534:Trans-Activators; C115443:XlnR protein, Aspergillus; D014994:Xylose; D001089:Arabinose; D005690:Galactose