Heterologous expression of metabotropic glutamate receptor subtype 1 in Saccharomyces cerevisiae

The upstream region of the isocitrate lyase gene (UPR-ICL) from the n-alkane-utilizing yeast Candida tropicalis serves as a useful promoter of gene expression in the yeast Saccharomyces cerevisiae. The production of rat metabotropic glutamate receptor 1α (mGluR1α), which belongs to the G-protein-coupled receptor (GPCR) family, was tested under the control of UPR-ICL. Expression of mGluR1α was found in recombinant clones and enhanced by replacing the signal sequence of mGluR1α with the corresponding region of the α-factor receptor (Ste2), which is a GPCR found in S. cerevisiae. Moreover, the membrane fraction from a recombinant clone associated with Vesl-1S/Homer-1a protein binds the mGluR1a in rat cerebellum. These results suggest that the UPR-ICL-controlled gene expression system is useful for heterologous GPCRs in S. cerevisiae.