title: White collar 1-induced photolyase expression contributes to UV-tolerance of Ustilago maydis.
abstract: Ustilago maydis is a phytopathogenic fungus causing corn smut disease. It also is known for its extreme tolerance to UV- and ionizing radiation. It has not been elucidated whether light-sensing proteins, and in particular photolyases play a role in its UV-tolerance. Based on homology analysis, U. maydis has 10 genes encoding putative light-responsive proteins. Four amongst these belong to the cryptochrome/photolyase family (CPF) and one represents a white collar 1 ortholog (wco1). Deletion mutants in the predicted cyclobutane pyrimidine dimer CPD- and (6-4)-photolyase were impaired in photoreactivation. In line with this, in vitro studies with recombinant CPF proteins demonstrated binding of the catalytic FAD cofactor, its photoreduction to fully reduced FADH(-) and repair activity for cyclobutane pyrimidine dimers (CPDs) or (6-4)-photoproducts, respectively. We also investigated the role of Wco1. Strikingly, transcriptional profiling showed 61 genes differentially expressed upon blue light exposure of wild-type, but only eight genes in the Δwco1 mutant. These results demonstrate that Wco1 is a functional blue light photoreceptor in U. maydis regulating expression of several genes including both photolyases. Finally, we show that the Δwco1 mutant is less tolerant against UV-B due to its incapability to induce photolyase expression.
authors.affiliation: Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Annika
authors.initials: A
authors.lastname: Brych
authors.affiliation: Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Judita
authors.initials: J
authors.lastname: Mascarenhas
authors.affiliation: Faculty of Biology, Department of Genetics, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Elaine
authors.initials: E
authors.lastname: Jaeger
authors.affiliation: Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Elzbieta
authors.initials: E
authors.lastname: Charkiewicz
authors.affiliation: Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Richard
authors.initials: R
authors.lastname: Pokorny
authors.affiliation: Faculty of Biology, Department of Genetics, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Bölker
authors.affiliation: Department of Organismic Interactions, Max-Planck-Institute for Terrestrial Microbiology, Karl-von-Frisch-Str. 10, Marburg, 35043, Germany.
authors.forename: Gunther
authors.initials: G
authors.lastname: Doehlemann
authors.affiliation: Faculty of Biology, Department of Plant Physiology and Photobiology, Philipps-University, Karl-von-Frisch-Str. 8, Marburg, 35032, Germany.
authors.forename: Alfred
authors.initials: A
authors.lastname: Batschauer
mesh_terms: D000220:Adaptation, Biological / Q000235:genetics*; D004255:Deoxyribodipyrimidine Photo-Lyase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal / Q000528:radiation effects*; D005810:Multigene Family; D009154:Mutation; D054730:Protein Interaction Domains and Motifs; D021381:Protein Transport; D014466:Ultraviolet Rays; D014588:Ustilago / Q000502:physiology* / Q000528:radiation effects*
chemical_list: D005656:Fungal Proteins; D004255:Deoxyribodipyrimidine Photo-Lyase
keywords: DNA-repair; U. maydis; UV-tolerance; light regulation; photolyase; white collar 1