Mating type locus encoded transcription factors

The genus Penicillium (phylum Ascomycota) has firstly been described in 1809 and comprises approximately 225 species. Penicillia show ubiquitous distribution; they are haploid, filamentous, and mitosporic. Morphologically, they are characterized by the production of an asexual reproductive structure, called penicillius Together with species of the genus Aspergillus, Penicillia belong to the order of Erotiales and are amongst the most prevalent fungi on earth. Many species have a high relevance either as pathogens or as important producers of food or pharmaceuticals.
In filamentous fungi, two alternative mating type (MAT) loci, namely MAT1-1 and MAT1-2, determine the sex of individual strains. These loci are termed idiomorphs to indicate that they do not represent alleles of a single gene. MAT loci from euascomycetes harbor one or more open reading frames (ORFs), of which at least one codes for a MAT TF. As a rule, the MAT1-1 locus encodes an α-domain TF and the alternative idiomorph, MAT1-2, is characterized by a gene coding for a TF with a high-mobility group (HMG)-domain. The corresponding genes are generally referred to as MAT1-1-1 and MAT1-2-1.
MAT loci have been characterized form a broad number of homo- and heterothallic ascomycetes. However, most loci are rather complex and encode more than one protein. As heterothallic species carry only a single MAT locus, they seem to be the ideal experimental system for getting mechanistic and functional insights into MAT TFs and their various cellular functions. Good examples for heterothallic species with MAT loci harboring only a single protein-coding gene are found in representatives of the Erotiales, e.g. Aspergillus fumigatus and Penicillium chrysogenum.

Experimental projects:

Functional and mechanistic insights into MAT transcription factors

•     Identification of interaction partners of MAT transcription factors on protein level
•     X-ray structure analysis of mating type transcription factors from Penicillium chrysogenum and Aspergillus fumigatus

Mating type systems and sexual life cycles in the Penicillia

•     Functional characterization of MAT transcription factors and time- and development-dependent expression of MAT target genes in Penicillium species
•     Induction of a sexual life cycle in industrially relevant Penicillium species

In this project, we perform a detailed bioinformatics and molecular analysis of the mating-type locus encoded transcription factors from the major human pathogen Aspergillus fumigatus and the Penicillin producer Penicillium chrysogenum. MAT locus encoded transcription factors are the master regulators of fungal mating, but their binding sites in the promoter regions of target genes are so far unknown. Using a highly purified recombinant MAT transcription factor, we provide a functional analysis of the DNA-binding sites, which seems to be conserved within members of the Eurotiales, suggesting common mechanisms for mating type locus driven functions beyond sexual development.

References

Mahmoudjanlou Y, Hoff B, Kück U (2019) Construction of a codon-adapted nourseotricin-resistance marker gene for efficient targeted gene deletion in the mycophenolic acid producer Penicillium brevicompactum. J Fungi (Basel) 5(4). pii: E96. doi: 10.3390/jof5040096.

Ianiri G, Fang Y, Dahlmann T, Janbon G, Kück U, Heitman J (2020) Mating-type specific ribosomal proteins control aspects of sexual reproduction in Cryptococcus neoformans. Genetics 214(3): 635-649. doi: 10.1534/genetics.119.302740

Mahmoudjanlou Y, Dahlmann T, Kück U (2020) Molecular analysis of mating type loci from the mycophenolic acid producer Penicillium brevicompactum: Phylogeny and MAT protein characterization suggest a cryptic sexual life cycle. Fungal Biol 124(9): 821-833. doi: 10.1016/j.funbio.2020.07.006.

Ramšak B, Markau J, Pazen T, Dahlmann TA, Krappmann S, Kück U (2020) The master regulator MAT1-1-1 of fungal mating binds to its targets via a conserved motif in the human pathogen Aspergillus fumigatus. G3 (Bethesda) 11(2): jkaa012. doi: 10.1093/g3journal/jkaa012