Abstract
The ciel 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 hyperproducer 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.
Original language | English |
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Pages (from-to) | 451-460 |
Number of pages | 10 |
Journal | Molecular and General Genetics |
Volume | 251 |
Issue number | 4 |
DOIs | |
Publication status | Published - 20 Aug 1996 |
MoE publication type | A1 Journal article-refereed |
Keywords
- Filamentous fungus
- Transcriptional regulation
- Zinc fingers