The F-box protein gene <i>exo</i> - <i>1</i> is a target for reverse engineering enzyme hypersecretion in filamentous fungi
Raphael Gabriel, Nils Thieme, Qian Liu, Fangya Li, L. Meyer, Simon Harth, Marina Jecmenica, Maya Ramamurthy, Jennifer L. Gorman, Blake A. Simmons, Kevin McCluskey, Scott Baker, Chaoguang Tian, Timo Schuerg, Steven W. Singer, André Fleißner, J. Philipp Benz
Abstract
Significance Lignocellulose-based biorefinery relies on plant cell wall degrading enzymes. Current genome editing methods can create fungal enzyme hypersecreter strains by design. However, the identification of candidate genes for targeted engineering of this trait remains a bottleneck, and the necessity of specific inducer molecules further complicates production. By the resequencing of a classical hypersecreting Neurospora crassa mutant, we uncovered that mutation of a gene encoding an F-box protein ( exo - 1 ) causes inducer-independent hypersecretion of amylases, invertase, and pectinases. Systems biology and genetic studies of Δ exo - 1 shed light on the regulation of enzyme secretion in filamentous fungi, allowing targeted reverse engineering of industrially employed fungi, such as Myceliophthora thermophila , demonstrating the power of classical mutants in combination with modern sequencing and omics technologies.