Aspergillus fumigatus is currently the major airborne fungal pathogen that menaces immunocompromised individuals. Germination of inhaled conidia is a hallmark of the early
infection process, but little is known about the underlying mechanisms. The intention of our ongoing studies is the identification of A. fumigatus
proteins that are differentially expressed during germination and may provide insights in the germination process. Using a proteomic approach, we identified AFUA_5G09330 as a major hyphal-specific
protein. This result was confirmed using
monoclonal antibodies generated in this study. AFUA_5G09330 belongs to a fungal-specific
protein family. The eponymous
CipC protein of A. nidulans has been shown to be induced by
concanamycin A, and transcriptional data from Cryptococcus neoformans demonstrate a strong up-regulation of the expression of a homologous gene during
infection. Our data provide evidence that AFUA_5G09330 is a monomeric, cytoplasmic
protein. We found no evidence for an overexpression of AFUA_5G09330 induced by
concanamycin A or other stress conditions. AFUA_5G09330 is exclusively found in the hyphal morphotype that enables an invasive growth of A. fumigatus during
infection. Further studies are required to define the
biological function of this hyphae-specific
protein and its potential relevance for the pathogenicity of A. fumigatus.