title: The first promoter for conditional gene expression in Acremonium chrysogenum: iron starvation-inducible mir1(P).
abstract: The filamentous fungus Acremonium chrysogenum is of enormous biotechnological importance as it represents the natural producer of the beta-lactam antibiotic cephalosporin C. However, a limitation in genetic tools, e.g. promoters for conditional gene expression, impedes genetic engineering of this fungus. Here we demonstrate that in A. chrysogenum iron starvation induces the production of the extracellular siderophores dimerumic acid, coprogen B, 2-N-methylcoprogen B and dimethylcoprogen as well as expression of the putative siderophore transporter gene, mir1. Moreover, we show that the promoter of mir1, mir1(P), is suitable for conditional expression of target genes in A. chrysogenum as shown by mir1(P)-driven and iron starvation-induced expression of genes encoding green fluorescence protein and phleomycin resistance. The obtained iron-starvation dependent phleomycin resistance indicates the potential use of this promoter for selection marker recycling. Together with easy scorable siderophore production, the co-regulation of mir1 expression and siderophore production facilitates the optimization of the inducing conditions of this expression system.
authors.affiliation: Christian Doppler Laboratory for Fungal Biotechnology, Division of Molecular Biology/Biocenter, Innrain 80-82, A-6020 Innsbruck, Austria.
authors.forename: Fabio
authors.initials: F
authors.lastname: Gsaller
authors.forename: Michael
authors.initials: M
authors.lastname: Blatzer
authors.forename: Beate
authors.initials: B
authors.lastname: Abt
authors.forename: Markus
authors.initials: M
authors.lastname: Schrettl
authors.forename: Herbert
authors.initials: H
authors.lastname: Lindner
authors.forename: Hubertus
authors.initials: H
authors.lastname: Haas
mesh_terms: D000164:Acremonium / Q000235:genetics* / Q000378:metabolism*; D005656:Fungal Proteins / Q000235:genetics / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D005800:Genes, Fungal; D005818:Genetic Engineering / Q000379:methods*; D007501:Iron / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D017262:Siderophores / Q000378:metabolism; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D005656:Fungal Proteins; D017262:Siderophores; D007501:Iron