« Previous Abstract"Determination of primary, secondary, and tertiary amines in air by direct or diffusion sampling followed by determination with liquid chromatography and tandem mass spectrometry"    Next AbstractA mathematical model of foraging in a dynamic environment by trail-laying Argentine ants »

G3 (Bethesda)

Title:		The master regulator MAT1-1-1 of fungal mating binds to its targets via a conserved motif in the human pathogen Aspergillus fumigatus
Author(s):		Ramsak B; Markau J; Pazen T; Dahlmann TA; Krappmann S; Kuck U;
Address:		"Allgemeine und Molekulare Botanik, Ruhr-Universitat Bochum, 44780 Bochum, Germany. Mikrobiologisches Institut - Klinische Mikrobiologie, Immunologie und Hygiene, Universitatsklinikum Erlangen und Friedrich-Alexander-Universitat (FAU) Erlangen-Nurnberg, 91054 Erlangen, Germany"
Journal Title:		G3 (Bethesda)
Year:		2021
Volume:		11
Issue:		2
Page Number:		-
DOI:		10.1093/g3journal/jkaa012
ISSN/ISBN:		2160-1836 (Electronic) 2160-1836 (Linking)
Abstract:		"Mating-type transcription factors are master regulators of sexually related signal transduction pathways in fungi; however, their recognition of specific DNA sequences from target genes is widely undetermined. Here, we identified and characterized the DNA-binding sequence of the MAT1-1-1 alpha-box domain transcription factor from the human pathogen Aspergillus fumigatus. In order to explore MAT1-1-1 DNA-binding targets, we used the previously reported MAT1-1-1 binding motif from Penicillium chrysogenum, in a bioinformatics approach. We identified 18 A. fumigatus genes carrying the MAT1.1 sequence in their upstream region, among them genes for the alpha-pheromone precursor (PpgA), G-protein-coupled pheromone receptor (PreA), and for TomA, an unidentified protein. To validate our prediction further, quantification of transcript levels showed a decrease in expression of ppgA, tomA, and others in a MAT1-1 deletion strain. For a functional analysis of the binding sites, truncated variants of the A. fumigatus MAT1-1-1 gene were introduced into Escherichia coli for heterologous expression. The yield of recombinant protein was further optimized for the AfMAT1-1-178-235 variant that harbors an extended alpha-box domain. AfMAT1-1-178-235 bound to a subset of the most strongly upregulated genes: ppgA, preA, and tomA. The DNA-binding specificity was confirmed by testing mutated binding sequences, as well as performing competition experiments with specific and non-specific sequences. Finally, equilibrium dissociation constants of 1.83 +/- 0.1 and 1.45 +/- 0.26 microM were determined for AfMAT1-1-178-235 and fusion protein GST-AfMAT1-1-178-235. Collectively, these findings provide further insights into AfMAT1-1-1-mediated gene expression and imply that alpha-box domain regulators from other members of Eurotiales control fungal development in a conserved manner"
Keywords:		"*Aspergillus fumigatus/genetics Fungal Proteins/genetics Fungi *Genes, Mating Type, Fungal Transcription Factors/genetics Escherichia coli protein synthesis DNA-binding motif human pathogen Aspergillus fumigatus mating type transcription factor;"
Notes:		"MedlineRamsak, Barbara Markau, Jessica Pazen, Tobias Dahlmann, Tim A Krappmann, Sven Kuck, Ulrich eng Research Support, Non-U.S. Gov't England 2021/02/19 G3 (Bethesda). 2021 Feb 9; 11(2):jkaa012. doi: 10.1093/g3journal/jkaa012"