Facile assembly and fluorescence-based screening method for heterologous expression of biosynthetic pathways in fungi
Metabolic Engineering – May 26, 2018
Source: OpenAlex
Summary
Producing psychotropic psilocybin in high yields is now possible, a significant advance in **Fungal Biology and Applications**. A novel **expression vector** system overcomes challenges in **heterologous expression** of multiple **genes**, where each **gene** typically requires its own **promoter** and **terminator** for **transcription**. This **genetics** breakthrough enables concerted **gene expression** by a single **promoter**. Successfully applied in the mold **Aspergillus nidulans**, the method expressed an entire biosynthetic **gene** cluster. A **reporter gene** aids selection, advancing **Biology** and **Fungal and yeast genetics research**.
Abstract
Heterologous expression of multi-gene biosynthetic pathways in eukaryotic hosts is limited by highly regulated individual monocistrons. Dissimilar to prokaryotes, each eukaryotic gene is strictly controlled by its own regulatory elements, such as promoter and terminator. Consequently, parallel transcription can occur only when a group of genes is synchronously activated. A strategy to circumvent this limitation is the concerted expression of multiple genes as a polycistron. By exploiting the "stop-carry on" mechanism of picornaviruses, we have designed a sophisticated, yet easy-to-assemble vector system to heterologously express multiple genes under the control of a single promoter. For facile selection of correctly transformed colonies by basic fluorescence microscopy, our vector includes a split gene for a fluorescent reporter protein. This method was successfully applied to produce the psychotropic mushroom alkaloid psilocybin in high yields by heterologous expression of the entire biosynthetic gene cluster in the mould Aspergillus nidulans.