The human beta 2-adrenergic receptor expressed in Schizosaccharomyces pombe retains its pharmacological properties

We have developed a rapid and efficient expression system to study the human beta 2 adrenergic receptor (hu beta 2AR) in the fission yeast Schizosaccharomyces pombe. This was achieved by cloning the hu beta 2AR gene, modified by replacement of the 5' untranslated and a small part of the N-terminal coding sequence (first 14 amino acids) with the corresponding region of the yeast Saccharomyces cerevisiae STE2 (alpha-factor receptor) gene. The gene was then placed under the control of a S. pombe constitutive promoter for alcohol dehydrogenase (adh). Hu beta 2AR expression was assessed by immunoblot analysis of the chimeric protein with an anti-STE2 serum raised against a dodecapeptide homologous to the N-terminal amino acids of STE2 and ligand binding was assayed using [125I]cyanopindolol. We demonstrate here that the chimeric receptor expressed in S. pombe exhibits the same characteristic ligand specificity and affinity as that of the authentic hu beta 2AR. This system constitutes a convenient alternative to existing methods for studying seven transmembrane domain receptors due to its simplicity and high reproducibility.