Patent ID: 7250263

Claim:
A mixture of recombinant yeast cells, each cell of which has a cell membrane and each cell of which comprises: (a) a heterologous receptor selected from the group consisting of: an FPRL-1 receptor, a C5a receptor and a thrombin receptor, which receptor is expressed in the cell membrane of said cell such that signal transduction activity via said receptor is modulated by interaction of an extracellular region of the receptor with an extracellular signal; and (b) a heterologous polypeptide, wherein the heterologous polypeptide is transported to a location allowing interaction with the extracellular region of the heterologous receptor expressed in the cell membrane; wherein collectively the mixture of cells expresses a library of said heterologous polypeptides, said library being expressible at a sufficient level such that modulation of the signal transduction activity of the heterologous receptor by a heterologous polypeptide within the library provides a detectable signal.