The novel repressor Rce2 competes with Ace3 to regulate cellulase gene expression in the filamentous fungus Trichoderma reesei. Issue 5 (19th October 2021)

• Record Type: Journal Article
• Authors: Chen, Yumeng; Wang, Wei; Liu, Pei; Lin, Aibo; Fan, Xingjia; Wu, Chuan; Li, Ni; Wei, Liujing; Wei, Dongzhi
• Is Part Of: Molecular microbiology. Volume 116:Issue 5(2021)
• Page Start: 1298
• Page End: 1314
• Publication Date: 2021-10-19
• Subjects: cellulase -- gene regulation -- repressor -- transcription factor -- Trichoderma reesei; Molecular microbiology -- Periodicals; 572.829
• DOI: 10.1111/mmi.14825
• Languages: English
• ISSNs: 0950-382X

Abstract

Abstract: The filamentous fungus Trichoderma reesei is widely used for industrial cellulase production. In T. reesei, cellulase gene expression is tightly controlled by a regulatory network involving multiple transcription factors. Here, we isolated a novel protein, Rce2, using a pull‐down assay and mass spectrometry analysis, from a partial carbon catabolite de‐repression mutant, T. reesei Rut‐C30, cultured under glucose‐repressing conditions. Deletion and overexpression of Rce2 in T. reesei wild‐type QM6a and mutant Rut‐C30 revealed that Rce2 acts as a r epressor of c ellulase gene e xpression. DNase I footprinting assays, electrophoretic mobility shift assays, and chromatin immunoprecipitation assays revealed that Rce2 was located in the nucleus and bound to the consensus sequences 5′‐(T/A)NNNNCCG‐3′ and 5′‐CGGNNNN(T/A)‐3′ in the promoters of cellulase‐related genes to repress their transcription. Additionally, Rce2 antagonized Ace3 binding to the cbh1 promoter to repress its transcription. However, Rce2 was not involved in Cre1‐mediated carbon catabolite repression. These results demonstrate the mechanism through which Rce2 represses the expression of cellulase genes and provide novel insights into the regulatory system of cellulases and methods that can be used for the regulation of gene expression in T. reesei . Abstract : We isolated a novel r epressor of c ellulase gene e xpression, Rce2, using a pull‐down assay and mass spectrometry analysis, from the filamentous fungus Trichoderma reesei Rut‐C30, cultured under glucose‐repressing conditions. Our data revealed that Rce2 antagonized the activator Ace3 binding to thecellulase cbh1 promoter to repress its transcription. Our results demonstrate the mechanism through which Rce2 represses the expression of cellulase genes and provide novel insights into the regulatory system of cellulases and methods that can be used for regulation of gene expression in T. reesei .