EAGER: SusChEM: Developing Temporal Compartmentalization Tools in Yeast to Enhance the Bioproduction of Phytosterols

University Of California-Riverside, Riverside CA

Investigators

Abstract

Plant steroids are complex, naturally occurring molecules that have a wide variety of pharmaceutical and agricultural applications; however, they are usually found in quite small amounts in plants, and they are difficult to synthesize chemically. This research project investigates ways to engineer yeasts to produce these molecules. To accomplish this goal, it is necessary to introduce into the yeast the ability to perform the targeted degradation of specific proteins. The researchers on this project are employing advanced biochemical methods in order to realize this alteration in the yeast. This research project include specific activities for high school students and for undergraduate students from a local community college, which will help in developing a highly trained technical workforce for the biotechnology industry. This research project provides a foundation for the development of programmable temporal regulation machinery for complex heterologous plant pathways in yeast. Such machinery employs yeast endogenous temporal compartmentalization strategies and an inducible protein degradation system associated with the endoplasmic reticulum (ER). Introducing complex plant pathways into microbial hosts including yeast has been highly challenging, mainly due to 1) the high burden from the expression of large numbers of plant enzymes; and 2) the lack of efficient coordination among the many heterologous enzymatic steps. A plant biosynthetic platform is required to incorporate and validate the proposed temporal regulation strategy, as is a targeted protein degradation (TPD) approach. The biosynthetic pathway of the plant steroid hormone brassinosteroids (BRs) is being verified and established in yeast, which will enable the downstream establishment of the proposed temporal regulation strategies. In addition, the feasibility of introducing TPD in the proposed temporal regulation strategy is being evaluated.