New avenues towards awakening silent fungal gene clusters

Secondary metabolites (SMs) play central roles as fitness factors of fungi. However, the vast majority of fungal-encoded chemical space is uncharted due to difficulties culturing and genetically manipulating many fungi. Previous strategies on activating fungal SMs have focused mainly on 1) activating endogenous gene clusters by either over-expressing the pathway-specific transcription factor or manipulating global regulators and 2) expressing the entire gene cluster in a heterologous host with native promotors. In a concerted effort, our labs have developed technologies to overcome these hurdles in order to characterize the vastly uncharacterized fungal-encoded chemical space.

The first untargeted approach uses our Fungal Artificial Chromosome (FAC) technology that is based on capturing secondary metabolite gene clusters from genomic DNA in a plasmid that can be transformed and expressed extra-chromosomally in an A. nidulans host strain. The second approach targets specific gene clusters of interest by using our Co-Inducible Nitrate (CoIN) promotor system that is based one-step yeast recombinational cloning thereby fusing targeted cluster genes to co-regulated promoters. The presentation will highlight recent advances from our labs towards SM discoveries from both of our technologies.