The role of carbon catabolite repression, carbon starvation and induction by exogenous protein in the regulation of extracellular protease production in Aspergillus nidulans.

Cheetham., Margaret E. Katz and Brian F.


Extracellular protease production was analysed in A. nidulans strains carrying mutations in genes thought to be involved in the response to carbon starvation (xprF and xprG) and genes which play a role in carbon catabolite repression (creA, creB and creC). In wild type strains, extracellular protease levels are low when any carbon source, including protein, is present suggesting that the extracellular protease genes are only expressed at high levels when no carbon source is available. No evidence for induction by exogenous protein in the presence of repressing or non-repressing carbon sources was observed in a wild type A. nidulans strain but protein does appear to affect production in some mutants. Though there was little difference in the levels of extracellular proteases in repressing and non-repressing carbon sources, mutations in cre genes affect production of extracellular proteases, suggesting that these genes may also be involved in the response to carbon starvation. Repression of extracellular proteases by glucose was not affected by deletion of the creA gene. The possibility that the xprF and xprG gene products play a direct role in the response of extracellular protease genes to carbon starvation is being explored by studying subcellular localisation of the xprF gene product in wild type and xprG mutant strains.

abstract No: 

Fungal Genet. Newsl. 50 (Supl):abstract

Full conference title: 

22nd Fungal Genetics Conference
    • Fungal Genetics Conference 22nd (2001)