Abstract: The present invention pertains to novel yeast cells which are useful for the expression of heterologous G protein coupled receptors. The yeast cells of the present invention can be used in screening assays which can be used to screen for modulators of G protein coupled receptors. Specifically, the invention provides novel yeast cells which express a heterologous G protein coupled receptor and mutant and/or chimeric G protein subunit molecules which serve to functionally integrate the heterologous into the pheromone signaling pathway of the yeast cell. The invention also provides for the expression of heterologous G protein coupled receptors which are functionally integrated into the yeast cell membrane using a yeast ? factor leader sequence. Drug discovery assays using the subject yeast cells are also provided.

Abstract: The present invention pertains to novel yeast cells which are useful for the expression of heterologous G protein coupled receptors. The yeast cells of the present invention can be used in screening assays which can be used to screen for modulators of G protein coupled receptors. Specifically, the invention provides novel yeast cells which express a heterologous G protein coupled receptor and mutant and/or chimeric G protein subunit molecules which serve to functionally integrate the heterologous into the pheromone signaling pathway of the yeast cell. The invention also provides for the expression of heterologous G protein coupled receptors which are functionally integrated into the yeast cell membrane using a yeast ? factor leader sequence. Drug discovery assays using the subject yeast cells are also provided.

Abstract: Yeast cells are engineered to express both a surrogate of a pheromone system protein (e.g., enzymes involved in maturation of ?-factor, transporters of a-factor, pheromone receptors, etc.) and a potential peptide modulator of the surrogate, in such a manner that the inhibition or activation of the surrogate affects a screenable or selectable trait of the yeast cells. Various additional features improve the signal-to-noise ratio of the screening/selection system.

Abstract: The present invention pertains to novel yeast cells which are useful for the expression of heterologous G protein coupled receptors. The yeast cells of the present invention can be used in screening assays which can be used to screen for modulators of G protein coupled receptors. Specifically, the invention provides novel yeast cells which express a heterologous G protein coupled receptor and mutant and/or chimeric G protein subunit molecules which serve to functionally integrate the heterologous into the pheromone signaling pathway of the yeast cell. The invention also provides for the expression of heterologous G protein coupled receptors which are functionally integrated into the yeast cell membrane using a yeast ? factor leader sequence. Drug discovery assays using the subject yeast cells are also provided.

Abstract: Yeast cells are engineered to express both a surrogate of a pheromone system protein (e.g., enzymes involved in maturation of &agr;-factor, transporters of a-factor, pheromone receptors, etc.) and a potential peptide modulator of the surrogate, in such a manner that the inhibition or activation of the surrogate affects a screenable or selectable trait of the yeast cells. Various additional features improve the signal-to-noise ratio of the screening/selection system.

Abstract: The present invention makes available a rapid, effective assay for screening and identifying pharmaceutically effective compounds that specifically interact with and modulate the activity of a cellular protein, e.g., a receptor or ion channel. The subject assay enables rapid screening of large numbers of compounds to identify those which act as an agonist or antagonist to the bioactivity of the cellular protein. The subject assay is particularly amenable for identifying surrogate ligands for receptors especially from small molecule or peptide libraries or from peptides produced by an autocrine system.