Researchers have developed a new genome editing tool, fPE7max, that enables precise manipulation of fungal genomes and reveals previously inaccessible drug-producing pathways, according to findings published in Nature Biotechnology on July 2. The team from the School of Engineering and Applied Science aimed to address challenges associated with studying filamentous fungi such as Aspergillus and Penicillium.
Gao, who led the research team, said traditional tools were insufficient for activating silent gene pathways in fungi: "To turn those silent pathways back on, we needed a powerful way to precisely manipulate fungal genome, such as editing their master regulatory genes, but traditional tools weren't up to the task."
First author Chunxiao Sun described the results: "We isolated 18 distinct complex molecules, eight of which possessed chemical structures entirely new to science. Of these uncovered molecules, three exhibited promising anti-cancer properties. These molecules can serve as lead compounds for disease treatment, providing a vital new pipeline for drug discovery." Sun also said one novel molecule showed selective toxicity against human breast, hepatic, and leukemia cancer cells.
The article explains that previous gene-editing technologies like CRISPR-Cas9 often caused unintended mutations in filamentous fungi. The newer prime editing technology allows more precise control but required adaptation for use in fungi. The team addressed two main challenges: stabilizing long guide RNAs using a protein called fLa and suppressing the fungus’s natural DNA repair system long enough for edits to become permanent.
Using fPE7max to edit regulatory sequences of the laeA gene enabled activation of silent biosynthetic pathways across several fungal species. This led researchers to discover molecules with potential anti-cancer properties. Gao said, "It's a compelling proof-of-concept demonstrating that the next generation of life-saving therapeutics might already exist in nature."
The research group plans further deployment of fPE7max across additional fungal species with hopes of systematically discovering novel natural products rather than relying on random searches.
