G-protein coupled receptor from yeast Saccharomyces cerevisiae.

The Saccharomyces cerevisiae GPR1 (G-protein coupled receptor) gene was isolated using two-hybrid system with a heterotrimeric GTP binding protein alpha subunit Gpa2p as a bait. The GPR1 gene encodes 961 amino acids with predicted seven transmembrane segments and two large cytosolic regions as third cytosolic loop with 350 amino acids where asparagine-rich region was found and the C-terminal region with 283 amino acids. The Gpr1p interacted with Gpa2p at C-terminal region with 131 amino acid residues as well as third cytosolic loop. Disruption of the GPR1 gene was not lethal and did not affect to the cell growth. The Gpr1p-GFP fusion protein localized at the cell surface. These results suggest that Gpr1p is a G-protein coupled receptor which localized at plasma membrane. It is likely that a Gpr1p monitors the extracellular signal such as nutrition and transduce it via Gpa2p a possible positive regulator of cAMP level.