PNNL

Abstract

Since the first CRISPR (clustered regularly inter-spaced short palindromic repeats)-Cas (CRISPR-associated) system was developed for creating double-stranded DNA breaks, it has been adapted and improved for different biotechnological applications. In this issue of The FEBS Journal, Arentshorst et al. developed a novel approach to enhance transgene expression of a specific protein, patulin synthase (PatE) from Penicillium expansum, in the important industrial filamentous fungus Aspergillus niger. Their technique involved the disruption of selected genes with countereffects on targeted protein pro-duction and simultaneous integration of glucoamylase landing sites into the disrupted gene locus such as protease regulator (prtT) in an ATP-dependent DNA helicase II subunit 1 (kusA or ku70)-deletion strain. Multiple copies of the PatE transgene expression cassette were introduced by CRISPR-Cas9-mediated insertion. The purified PatE was further used for structural and functional studies, and the technique lay the foundation for elevating the overall production of various proteins or chemicals in those industrially important fungi.