The Glucose Repressor Gene cre1 of Trichoderma: Isolation and Expression of a Full-Length and a Truncated Mutant Form

Mol Gen Genet. 1996 Jun 24;251(4):451-60. doi: 10.1007/BF02172374.

Abstract

The cre1 genes of the filamentous fungi Trichoderma reesei and T. harzianum were isolated and characterized. The deduced CREI proteins are 46% identical to the product of the glucose repressor gene creA of Aspergillus nidulans, encoding a DNA-binding protein with zinc fingers of the C2H2 type. The cre1 promoters contain several sequence elements that are identical to the previously identified binding sites for A. nidulans CREA. Steady-state mRNA levels for cre1 of the T. reesei strain QM9414 varied depending on the carbon source, being low on glucose-containing media. These observations suggest that cre1 expression may be autoregulated. The T. reesei strain Rut-C30, a hyper-producer of cellulolytic enzymes, was found to express a truncated form of the cre1 gene (cre1-1) with an ORF corresponding to a protein of 95 amino acids with only one zinc finger. Unlike QM9414 the strain Rut-C30 produced cellulase mRNAs on glucose-containing medium and transformation of the full-length cre1 gene into this strain caused glucose repression of cbh1 expression, demonstrating that cre1 regulates cellulase expression.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Carbon / metabolism
  • Cellulase / biosynthesis
  • Cellulase / genetics
  • DNA-Binding Proteins / biosynthesis*
  • DNA-Binding Proteins / chemistry
  • DNA-Binding Proteins / genetics*
  • Fungal Proteins*
  • Gene Expression Regulation, Fungal
  • Glucose / metabolism
  • Homeostasis
  • Molecular Sequence Data
  • Mutation
  • Promoter Regions, Genetic
  • Repressor Proteins / biosynthesis*
  • Repressor Proteins / chemistry
  • Repressor Proteins / genetics*
  • Sequence Alignment
  • Sequence Analysis, DNA
  • Sequence Homology, Amino Acid
  • Trichoderma / chemistry
  • Trichoderma / genetics*

Substances

  • DNA-Binding Proteins
  • Fungal Proteins
  • Repressor Proteins
  • Carbon
  • Cellulase
  • Glucose

Associated data

  • GENBANK/X95368
  • GENBANK/X95369