Abstract
The xylanase III gene (xyn3) from the filamentous fungus Trichoderma reesei PC-3-7 is only induced by cellulose, its derivatives and L-sorbose, but not by xylan. In this study, we defined three cis-acting elements within the xyn3 upstream region by using detailed deletion and mutation analysis. In addition to the Xyr1/ACEII-binding motif (5'-GGCTAA-3'), the analogous motifs 5'-GGCTAT-3' and 5'-GGCAAA-3' presented as an inverted repeat spaced by 16-bp internal sequences were identified as essential elements for xyn3 expression. Electrophoretic mobility shift assay using heterologously expressed Xyr1 demonstrates that all the identified cis-acting elements are able to interact with Xyr1. Furthermore, no xyn3 transcripts were formed in the xyr1-knockout strain upon induction by sophorose and L-sorbose. These results indicate that xyn3 expression is transcriptionally regulated by Xyr1, and suggest that the 5'-GGCTAT-3' and 5'-GGCAAA-3' motifs play roles in Xyr1-mediated cellulase and xylanase gene expression in T. reesei.
Original language | English |
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Pages (from-to) | 1094-102 |
Number of pages | 9 |
Journal | Fungal genetics and biology : FG & B |
Volume | 45 |
Issue number | 7 |
DOIs | |
Publication status | Published - Jul 2008 |
Keywords
- Base Sequence
- DNA-Binding Proteins
- Electrophoretic Mobility Shift Assay
- Fungal Proteins
- Gene Expression Regulation, Fungal
- Genes, Reporter
- Response Elements
- Sequence Deletion
- Transcription, Genetic
- Trichoderma
- Xylosidases
- Journal Article
- Research Support, Non-U.S. Gov't