Screening for High-Yielding Saccharomyces cerevisiae Clones: Using a Green Fluorescent Protein Fusion Strategy in the Production of Membrane Proteins

The overproduction of eukaryotic membrane proteins in milligram quantities is a major bottleneck for their further biochemical and structural investigation. Production trials exploring a range of input factors can be rationalized to improve the likelihood of success. Here we discuss some of these factors in combination with the use of a GFP-based Saccharomyces cerevisiae system that enables a quick turnaround time from clone construction to production trials. Since membrane-integrated levels do not necessarily correlate with the amount of functional recombinant protein, we also include the use of fluorescence-detection size exclusion chromatography (FSEC). Using FSEC, the quality of the recombinant material can also be rapidly evaluated as demonstrated for the functional production of the rat vesicular glutamate transporter (VGLUT2) and the human glucose transporter (GLUT1) (5).