Truncation of the transcriptional repressor protein Cre1 in Trichoderma reesei Rut-C30 turns it into an activator

• DOI: 10.1186/s40694-018-0059-0
• Publication Date: 2018-08-07T06:15:32Z
• Authors: Alice Rassinger; Agnieszka Gacek-M...; Joseph Strauss; Robert L. Mach; Astrid R. Mach-Ai...
• Keywords: 0303 health sciences; 03 medical and health sciences; Trichoderma reesei; Research; Cre1; Cellulases; Carbon catabolite repression; Transcription factor; TP248.13-248.65; Gene regulation; Biotechnology

The filamentous fungus Trichoderma reesei (T. reesei) is a natural producer of cellulolytic and xylanolytic enzymes therefore industrially used. Many industries require high amounts enzymes, in particular cellulases. Strain improvement strategies by random mutagenesis yielded the industrial ancestor strain Rut-C30. A key property Rut-C30 partial release from carbon catabolite repression caused truncation repressor Cre1 (Cre1-96). In T. wild-type full cre1 deletion leads to pleiotropic effects strong growth impairment, while truncated cre1-96 enhances activity without effect deficiencies. However, it still unclear which function Cre1-96 has Rut-C30.In this study, we deleted constitutively expressed We found that presence crucial for its performance under inducing conditions. case Cre1-96, cellulase could further be improved approximately twofold. led deficiencies morphological abnormalities. An silico domain prediction revealed all necessary properties classic transactivator needs. Consequently, investigated cellular localization fluorescence microscopy using an eYFP-tag. localized fungal nuclei both, repressing Furthermore, chromatin immunoprecipitation enrichment upstream regulatory region main cellulases xylanases, Xyr1. Interestingly, transcript levels show same patterns as ones xyr1 conditions.The findings suggest turns into activating regulator, primarily exerts role approaching xyr1. conversion proteins potential activators other biotechnologically used fungi can applied increase their enzyme production capacities.