Production of Pyomelanin, a Second Type of Melanin, via the Tyrosine Degradation Pathway in Aspergillus fumigatus

• DOI: 10.1128/aem.02077-08
• Publication Date: 2008-11-22T02:10:56Z
• Authors: Jeannette Schmale...; Venelina Sugareva; Peter Gebhardt; Robert Winkler; Olaf Kniemeyer; Thorsten Heinekamp; Axel A. Brakhage
• Keywords: Homogentisic acid

Aspergillus fumigatus is the most important airborne fungal pathogen of immunosuppressed humans. A. able to produce dihydroxynaphthalene melanin, which predominantly present in conidia. Its biosynthesis an virulence determinant. Here, we show that alternative i.e., pyomelanin, by a different pathway, starting from L-tyrosine. Proteome analysis indicated l-tyrosine degradation enzymes are synthesized when fungus grown with L-tyrosine medium. To investigate pathway detail, deleted genes encoding essential for pigment production, homogentisate dioxygenase (hmgA) and 4-hydroxyphenylpyruvate (hppD). Comparative Fourier transform infrared spectroscopy synthetic pyomelanin extracted cultures confirmed identity observed as pyomelanin. In hmgA deletion strain, HmgA activity was abolished accumulation homogentisic acid provoked increased formation. contrast, were not hppD mutant. Germlings mutant showed sensitivity reactive oxygen intermediates. The transcription both studied induced These results function predicted fumigatus. Homogentisic major intermediate, leading similar humans alkaptomelanin.