Characterization of cross-species transcription and splicing from Penicillium to S. cerevisiae.

Heterologous expression of eukaryotic gene clusters in yeast has been widely used for producing high-value chemicals and bioactive secondary metabolites. However, eukaryotic transcription cis-elements are still under-characterized, and the cross-species expression mechanism remains poorly understood. Here we used the whole expression unit (including original promoter, terminator and open reading frame with introns) of orotidine 5'-monophosphate decarboxylases from fourteen Penicillium species as a showcase, and analyzed their cross-species expression in Saccharomyces cerevisiae. We found that pyrG promoters from the Penicillium species could drive URA3 expression in yeast, and that inefficient cross-species splicing of Penicillium introns might result in weak cross-species expression. Thus, this study demonstrates cross-species expression from Penicillium to yeast, and sheds light on the opportunities and challenges of cross-species expression of fungi expression units and gene clusters in yeast without refactoring for novel natural product discovery.