Abstract: Compositions for nematode growth and methods for using the same for nematode viability are described. The compositions contain a solid matrix material that is dispersed in a liquid medium. The solid matrix can be immersed, bathed, and/or interspersed in a liquid medium to form a composite culture that is capable of maintaining or growing nematodes at unexpectedly high densities and/or with nominal stress pathway activity. Other embodiments are described.

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: The invention provides recombinant cells that have been engineered such that ligand stimulation of a receptor expressed by the cells leads to amplified signal transduction responses. In one embodiment, the receptor-expressing cells have been engineered to carry a heterologous DNA construct comprising a gene encoding a protein that activates the signal transduction pathway, which gene is operatively linked to a promoter that is responsive to activation of the signal transduction pathway. Stimulation of the receptor by a ligand leads to expression of the heterologous DNA construct encoding the protein that activates the signal transduction pathway such that signals generated by ligand binding to the receptor are amplified. Preferred cells are yeast cells expressing heterologous G protein coupled receptors functionally coupled to the yeast pheromone response pathway and overexpressing Ste5p, Ste4p, Ste12p, Ste11p or a dominant truncation allele of Ste20 via a pheromone-responsive promoter.

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: 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.