Abstract: Mammalian adenylyl cyclases are functionally expressed in yeast cells. The yeast cells may be used to screen for inhibitors or activators of the adenylyl cyclase, or of a regulator of adenylyl cyclase which is functionally co-expressed in the yeast cell. Methods of identifying such inhibitors, activators and regulators are also disclosed.

Abstract: Yeast cells are engineered to express both a surrogate of a pheromone system protein (e.g., enzymes involved in maturation of .alpha.-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: Yeast cells are engineered to express both a surrogate of a pheromone system protein (e.g., enzymes involved in maturation of .alpha.-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: A yeast promoter inducible by the appropriate pheromone and a method of expressing a gene of interest in substantial quantities by placing it under the control of the inducible promoter. DNA encoding a protein of interest is fused or linked to a pheromone - inducible yeast promoter, such as the FUSI or the FUS2 promoter, and the fusion is inserted onto a high copy vector; the resulting product is introduced into wild type yeast cells. Stimulation of these yeast cells by the appropriate pheromone results in induction of transcription of the yeast promoter and expression of the protein of interest in substantial quantities.