PhiReX: a programmable and red light-regulated protein expression switch for yeast.

Area of Science:

• Synthetic Biology
• Molecular Biology
• Biotechnology

Background:

• Highly regulated protein expression systems are crucial for engineering complex biological pathways.
• Controlling gene expression with precision, dose-dependency, and reversibility is essential for advanced biotechnological applications.

Purpose of the Study:

• To develop a novel red/far-red light-regulated protein expression system, named PhiReX, for use in Saccharomyces cerevisiae.
• To enable flexible and tunable control over protein expression for applications in synthetic biology and industrial fermentation.

Main Methods:

• PhiReX system combines a customizable synTALE DNA-binding domain with the VP64 activation domain.
• Utilizes light-sensitive dimerization of Arabidopsis thaliana photoreceptor PhyB and PIF3.
• Genome integration of red light-sensing components and episomal high-copy reporter constructs for robust expression.

Main Results:

• Achieved robust gene expression and high protein levels using the PhiReX system.
• Demonstrated the flexibility to exchange genes of interest and DNA-binding domains for regulating various targets.
• Engineered yeast for endogenous chromophore production, enabling low-cost induction for industrial fermentation.

Conclusions:

• PhiReX provides a powerful tool for precise, light-inducible, and reversible control of gene expression in yeast.
• The system's flexibility and cost-effectiveness make it suitable for industrial applications and complex synthetic biology endeavors.
• High-level induction was sustained for at least 48 hours, demonstrating system stability and efficacy.