G-Protein Coupled Receptor from Yeast Saccharomyces cerevisiae

Abstract

The Saccharomyces cerevisiae GPR1( G-protein coupled receptor) gene was isolated using two-hybrid system with a heterotrimeric GTP binding protein α subunit Gpa2p as a bait. The GPR1gene 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 GPR1gene 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.