title: Transcriptome analysis of cyclic AMP-dependent protein kinase A-regulated genes reveals the production of the novel natural compound fumipyrrole by Aspergillus fumigatus.
abstract: Aspergillus fumigatus is an opportunistic human pathogenic fungus causing life-threatening infections in immunocompromised patients. Adaptation to different habitats and also virulence of the fungus depends on signal perception and transduction by modules such as the cyclic AMP-dependent protein kinase A (PKA) pathway. Here, by transcriptome analysis, 632 differentially regulated genes of this important signaling cascade were identified, including 23 putative transcriptional regulators. The highest upregulated transcription factor gene was located in a previously unknown secondary metabolite gene cluster, which we named fmp, encoding an incomplete non-ribosomal peptide synthetase, FmpE. Overexpression of the regulatory gene fmpR using the Tet(On) system led to the specific expression of the other six genes of the fmp cluster. Metabolic profiling of wild type and fmpR overexpressing strain by HPLC-DAD and HPLC-HRESI-MS and structure elucidation by NMR led to identification of 5-benzyl-1H-pyrrole-2-carboxylic acid, which we named fumipyrrole. Fumipyrrole was not described as natural product yet. Chemical synthesis of fumipyrrole confirmed its structure. Interestingly, deletion of fmpR or fmpE led to reduced growth and sporulation of the mutant strains. Although fmp cluster genes were transcribed in infected mouse lungs, deletion of fmpR resulted in wild-type virulence in a murine infection model.
authors.affiliation: Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), 07745, Jena, Germany; Institute for Microbiology, Friedrich Schiller University, 07745, Jena, Germany.
authors.forename: Juliane
authors.initials: J
authors.lastname: Macheleidt
authors.forename: Kirstin
authors.initials: K
authors.lastname: Scherlach
authors.forename: Toni
authors.initials: T
authors.lastname: Neuwirth
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Schmidt-Heck
authors.forename: Maria
authors.initials: M
authors.lastname: Straßburger
authors.forename: Joseph
authors.initials: J
authors.lastname: Spraker
authors.forename: Joshua A
authors.initials: JA
authors.lastname: Baccile
authors.forename: Frank C
authors.initials: FC
authors.lastname: Schroeder
authors.forename: Nancy P
authors.initials: NP
authors.lastname: Keller
authors.forename: Christian
authors.initials: C
authors.lastname: Hertweck
authors.forename: Thorsten
authors.initials: T
authors.lastname: Heinekamp
authors.forename: Axel A
authors.initials: AA
authors.lastname: Brakhage
mesh_terms: D000818:Animals; D001232:Aspergillus fumigatus / Q000235:genetics* / Q000378:metabolism / Q000472:pathogenicity; D000242:Cyclic AMP / Q000378:metabolism; D017868:Cyclic AMP-Dependent Protein Kinases / Q000235:genetics* / Q000378:metabolism; D004195:Disease Models, Animal; D005656:Fungal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D020869:Gene Expression Profiling; D015966:Gene Expression Regulation, Fungal; D008168:Lung / Q000473:pathology; D051379:Mice; D005810:Multigene Family; D010453:Peptide Synthases / Q000235:genetics; D011392:Proline / Q000031:analogs & derivatives* / Q000378:metabolism; D055732:Pulmonary Aspergillosis / Q000382:microbiology / Q000473:pathology; D015398:Signal Transduction / Q000235:genetics
chemical_list: D005656:Fungal Proteins; C002986:2-pyrrolecarboxylic acid; D011392:Proline; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D010453:Peptide Synthases