[The mutational analysis of carbon catabolite repression in filamentous fungus Penicillium canescens].

ABSTRACT

Penicillium canescens strain F178 is a natural producer of beta-galactosidase and endo-1,4-beta-xylanase. The transcription of genes bgaS and xylA, coding for these proteins, is subject to carbon catabolite repression. The system for selective isolation of regulatory mutants in P. canescens is developed. Two strains from the mutant collection are studied in details. It is shown that both mutations can be complement by creA gene of P. canescens, encoding global regulator of carbon catabolite repression in filamentous fungi. creA(-) alleles contain frameshift mutations in C-domain of CreA. Gene xylA is derepressed in mutants at transcription level in the presence of D-glucose. A transcription of creA gene in mutants is also derepressed proving effect of autoregulation for this gene.