Discovery of cryptic polyketide metabolites from dermatophytes using heterologous expression in Aspergillus nidulans

Dermatophytes belonging to the Trichophyton and Arthroderma genera cause skin infections in humans and animals. From genome sequencing data, we mined a conserved gene cluster among dermatophytes that are homologous to one that produces an immunosuppressive polyketide in Aspergillus fumigatus. Using a recombination-based cloning strategy in yeast, we constructed fungal heterologous expression vectors that encode the cryptic clusters. When integrated into the model Aspergillus nidulans host, a structurally related compound neosartoricin B was formed, suggesting a possible role of this compound in the pathogenesis of these strains.