Discovery of Putative Phosphorylation Sites in Cre1 and Ace1 as Engineering Targets for Enhanced Cellulase Production in Trichoderma reesei
- 1State Key Lab of Bioreactor Engineering, East China University of Science and Technology, Shanghai 200237, China
Abstract
In the filamentous fungus Trichoderma reesei, cellulase production is subject to carbon catabolite repression (CCR) mediated by the key repressors Cre1 and Ace1. In this study, we identified two previously unreported phosphorylation sites—S204 in Cre1 and S145 in Ace1—through phosphoproteomic profiling. Site-directed mutagenesis revealed that dephosphorylation-mimicking mutations (Cre1S204A and Ace1S145A) significantly relieved CCR and promoted cellulase biosynthesis, while phosphomimetic mutations exerted opposite effects. Notably, the Cre1S204A/Ace1S145A double mutant exhibited a combined enhancement in cellulase activity, achieving a 0.7-fold increase in pNPCase activity compared to the parental strain, along with substantially upregulated cellulase gene transcription and increased extracellular CBH1 accumulation. These results demonstrate that S204 and S145 are functionally relevant phosphorylation sites that negatively modulate cellulase production. Our findings provide novel engineering targets for strain improvement and, more broadly, open new avenues for investigating the phosphorylation-based regulatory mechanisms of Cre1 and Ace1 in future studies. From an applied perspective, the work offers a straightforward and effective genetic strategy for the rational design of high-performance fungal strains for lignocellulose bioconversion.
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BibTeX
@article{liu2026discovery,
title = {{Discovery of Putative Phosphorylation Sites in Cre1 and Ace1 as Engineering Targets for Enhanced Cellulase Production in Trichoderma reesei}},
author = {Jiahui Liu and Sunxing Wang and Xin Gao and Yumeng Chen and Wei Wang},
journal = {International Journal of Molecular Sciences},
year = {2026},
month = oct,
doi = {10.3390/ijms27209145},
url = {https://www.mdpi.com/1422-0067/27/20/9145},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Discovery of Putative Phosphorylation Sites in Cre1 and Ace1 as Engineering Targets for Enhanced Cellulase Production in Trichoderma reesei
AU - Jiahui Liu
AU - Sunxing Wang
AU - Xin Gao
AU - Yumeng Chen
AU - Wei Wang
PY - 2026
DA - 2026/10/15
JO - International Journal of Molecular Sciences
DO - 10.3390/ijms27209145
UR - https://www.mdpi.com/1422-0067/27/20/9145
AB - In the filamentous fungus Trichoderma reesei, cellulase production is subject to carbon catabolite repression (CCR) mediated by the key repressors Cre1 and Ace1. In this study, we identified two previously unreported phosphorylation sites—S204 in Cre1 and S145 in Ace1—through phosphoproteomic profiling. Site-directed mutagenesis revealed that dephosphorylation-mimicking mutations (Cre1S204A and Ace1S145A) significantly relieved CCR and promoted cellulase biosynthesis, while phosphomimetic mutations exerted opposite effects. Notably, the Cre1S204A/Ace1S145A double mutant exhibited a combined enhancement in cellulase activity, achieving a 0.7-fold increase in pNPCase activity compared to the parental strain, along with substantially upregulated cellulase gene transcription and increased extracellular CBH1 accumulation. These results demonstrate that S204 and S145 are functionally relevant phosphorylation sites that negatively modulate cellulase production. Our findings provide novel engineering targets for strain improvement and, more broadly, open new avenues for investigating the phosphorylation-based regulatory mechanisms of Cre1 and Ace1 in future studies. From an applied perspective, the work offers a straightforward and effective genetic strategy for the rational design of high-performance fungal strains for lignocellulose bioconversion.
SN - 1422-0067
ER -