Systems Approaches to Predict the Functions of Glycoside Hydrolases during the Life Cycle of XXXX Using Developmental Mutants    brlA and    flbA.

@entity505 @entity11150 @entity1735 @entity3456
BACKGROUND: The filamentous fungus @entity11150 encounters @entity505 starvation in nature as well as during industrial fermentations. In response, regulatory networks initiate and control autolysis and sporulation. @entity1735 -active enzymes play an important role in these processes, for example by modifying cell walls during spore cell wall biogenesis or in cell wall degradation connected to autolysis. RESULTS: In this study, we used developmental mutants (  flbA and   brlA) which are characterized by an aconidial phenotype when grown on a plate, but also in bioreactor-controlled submerged cultivations during @entity505 starvation. By comparing the transcriptomes, proteomes, enzyme activities and the fungal cell wall compositions of a wild type A. @entity3456 and these developmental mutants during @entity505 starvation, a global overview of the function of @entity1735 -active enzymes is provided. Seven genes encoding @entity1735 -active enzymes, including cfcA, were expressed during starvation in all strains; they may encode enzymes involved in cell wall recycling. Genes expressed in the wild-type during starvation, but not in the developmental mutants are likely involved in conidiogenesis. Eighteen of such genes were identified, including characterized sporulation-specific chitinases and An15g02350, member of the recently identified @entity1735 -active enzyme family AA11. Eight of the eighteen genes were also expressed, independent of FlbA or BrlA, in vegetative mycelium, indicating that they also have a role during vegetative growth. The   flbA strain had a reduced specific growth rate, an increased chitin content of the cell wall and specific expression of genes that are induced in response to cell wall stress, indicating that integrity of the cell wall of strain   flbA is reduced. CONCLUSION: The combination of the developmental mutants   flbA and   brlA resulted in the identification of enzymes involved in cell wall recycling and sporulation-specific cell wall modification, which contributes to understanding cell wall remodeling mechanisms during development.
