CreA phosphorylation sites are important for the regulation of carbon catabolite repression in filamentous fungi

ABSTRACT: Saprobic microorganisms, such as filamentous fungi of the genus Aspergillus, are of particular interest for biotechnological applications due to their natural capacity to secrete plant cell wall-degrading enzymes that are known as carbohydrate-active enzymes (CAZy). The presence of easily metabolizable sugars such as glucose, whose concentrations increase during plant biomass hydrolysis, results in the repression of CAZy-encoding genes, in a process known as carbon catabolite repression (CCR), which is undesired for the purpose of large-scale enzyme production. To date, the C2H2 transcription factor CreA has been described as the major CC-repressor in Aspergillus spp. Although CreA-mediated CCR has been extensively studied, less is known about the regulation of CreA itself and the role of post-translational modifications in this process. In this work, phosphorylation sites were identified by mass spectrometry on A. nidulans CreA and subsequently four sites, S262, S268, T308 and S319, were chosen to be mutated to non-phosphorylatable residues before their effects on CCR in both CC-repressing and de-repressing conditions were studied. Sites S262, S268 and T308 are important for CreA protein accumulation and cellular localization and repression of enzyme activities. In contrast, site S319 is key for CreA degradation and induction of enzyme activities. All sites were shown to be important for glycogen and trehalose metabolism. This study highlights the importance of CreA phosphorylation sites for the regulation of CCR. Furthermore, these sites are interesting targets for biotechnological strain engineering without the need to delete essential genes which can result in undesired side effects.

OTHER RELATED OMICS DATASETS IN: MODEL1109130000 MODEL1909260003 MODEL1909260004 MODEL1703310000 MODEL1909260005 MODEL1909260006 MODEL1311110000 MODEL1311110001

INSTRUMENT(S): Q Exactive

ORGANISM(S): Emericella Nidulans (aspergillus Nidulans)

SUBMITTER: Thomas Krüger  

LAB HEAD: Olaf Kniemeyer

PROVIDER: PXD018967 | Pride | 2021-02-18

REPOSITORIES: Pride