Transcription Factor SomA Is Required for Adhesion, Development and Virulence of the Human Pathogen Aspergillus fumigatus

PLoS Pathogens

Henriette Irmer¹  Christoph Sasse¹  Susanna A. Braus-Stromeyer¹  Chi-Jan Lin¹  Oliver Valerius¹  Jennifer Gerke¹  Gerhard H. Braus¹  Britta Herzog²  Maria Straßburger²  Holm Frauendorf³  Van Tuan Tran⁴  Thorsten Heinekamp⁴ 

[1] Department of Molecular Microbiology and Genetics, Institute of Microbiology & Genetics, Georg-August-University Göttingen, Göttingen, Germany;Institute for Microbiology, Friedrich Schiller University, Jena, Germany;Institute for Organic and Biomolecular Chemsitry, Georg-August-University Göttingen, Göttingen, Germany;Molecular and Applied Microbiology, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Jena, Germany

关键词: Saccharomyces cerevisiae;    Aspergillus fumigatus;    Plant fungal pathogens;    C;    ida albicans;    Gene expression;    Mouse models;    Fungal genetics;    Biofilms;   

DOI  :  10.1371/journal.ppat.1005205

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

The transcription factor Flo8/Som1 controls filamentous growth in Saccharomyces cerevisiae and virulence in the plant pathogen Magnaporthe oryzae. Flo8/Som1 includes a characteristic N-terminal LUG/LUH-Flo8-single-stranded DNA binding (LUFS) domain and is activated by the cAMP dependent protein kinase A signaling pathway. Heterologous SomA from Aspergillus fumigatus rescued in yeast flo8 mutant strains several phenotypes including adhesion or flocculation in haploids and pseudohyphal growth in diploids, respectively. A. fumigatus SomA acts similarly to yeast Flo8 on the promoter of FLO11 fused with reporter gene (LacZ) in S. cerevisiae. FLO11 expression in yeast requires an activator complex including Flo8 and Mfg1. Furthermore, SomA physically interacts with PtaB, which is related to yeast Mfg1. Loss of the somA gene in A. fumigatus resulted in a slow growth phenotype and a block in asexual development. Only aerial hyphae without further differentiation could be formed. The deletion phenotype was verified by a conditional expression of somA using the inducible Tet-on system. A adherence assay with the conditional somA expression strain indicated that SomA is required for biofilm formation. A ptaB deletion strain showed a similar phenotype supporting that the SomA/PtaB complex controls A. fumigatus biofilm formation. Transcriptional analysis showed that SomA regulates expression of genes for several transcription factors which control conidiation or adhesion of A. fumigatus. Infection assays with fertilized chicken eggs as well as with mice revealed that SomA is required for pathogenicity. These data corroborate a complex control function of SomA acting as a central factor of the transcriptional network, which connects adhesion, spore formation and virulence in the opportunistic human pathogen A. fumigatus.

【 授权许可】

CC BY