title: Microarray hybridization analysis of light-dependent gene expression in Penicillium chrysogenum identifies bZIP transcription factor PcAtfA.
abstract: The fungal velvet complex is a light-dependent master regulator of secondary metabolism and development in the major penicillin producer, Penicillium chrysogenum. However, the light-dependent mechanism is unclear. To identify velvet-dependent transcriptional regulators that show light-regulated expression, we performed microarray hybridizations with RNA isolated from P. chrysogenum ΔPcku70 cultures grown under 13 different long-term, light-dependent growth conditions. We compared these expression data to data from two velvet complex deletion mutants; one lacked a subunit of the velvet complex (ΔPcvelA), and the other lacked a velvet-associated protein (ΔPclaeA). We sought to identify genes that were up-regulated in light, but down-regulated in ΔPcvelA and ΔPclaeA. We identified 148 co-regulated genes that displayed this regulatory pattern. In silico analyses of the co-regulated genes identified six proteins with fungal-specific transcription factor domains. Among these, we selected the bZIP transcription factor, PcAtfA, for functional characterization in deletion and complementation strains. Our data clearly indicates that PcAtfA governs spore germination. This comparative analysis of different microarray hybridization data sets provided results that may be useful for identifying genes for future functional analyses.
authors.affiliation: Christian Doppler Laboratory for Fungal Biotechnology, Lehrstuhl für Allgemeine und Molekulare Botanik, Ruhr-Universität Bochum, Bochum, Germany.
authors.forename: Simon
authors.initials: S
authors.lastname: Wolfers
authors.forename: Jens
authors.initials: J
authors.lastname: Kamerewerd
authors.forename: Minou
authors.initials: M
authors.lastname: Nowrousian
authors.forename: Claudia
authors.initials: C
authors.lastname: Sigl
authors.forename: Ivo
authors.initials: I
authors.lastname: Zadra
authors.forename: Hubert
authors.initials: H
authors.lastname: Kürnsteiner
authors.forename: Ulrich
authors.initials: U
authors.lastname: Kück
authors.forename: Sandra
authors.initials: S
authors.lastname: Bloemendal
mesh_terms: D050976:Basic-Leucine Zipper Transcription Factors / Q000235:genetics*; D003198:Computer Simulation; D005656:Fungal Proteins / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D008027:Light; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis; D010408:Penicillium chrysogenum / Q000235:genetics* / Q000502:physiology; D017384:Sequence Deletion; D013172:Spores, Fungal / Q000235:genetics / Q000254:growth & development*
chemical_list: D050976:Basic-Leucine Zipper Transcription Factors; D005656:Fungal Proteins
keywords: Light regulation; Microarray; Penicillium chrysogenum; bZIP transcription factor