Patent ID: 7732133

Claim:
A method of screening for a ligand that can bind to at least one of two or more kinds of receptors, wherein said method comprises the steps of: (i)providing a composition comprising cells transformed with expression vectors encoding two or more kinds of receptors and expressing said two or more kinds of receptors, each of said receptors comprising (a) a common signal-transducing domain derived from a receptor selected from the group consisting of hematopoietic factor receptor family, cytokine receptor family, tyrosine kinase-type receptor family, serine/threonine kinase-type receptor family, TNF receptor family, G protein-coupled receptor family, GPI-anchored receptor family, tyrosine phosphatase-type receptor family, cell adhesion receptor family, and hormone receptor family, and (b) a ligand-binding domain derived from a receptor selected from the group consisting of hematopoietic factor receptor family, cytokine receptor family, tyrosine kinase-type receptor family, serine/threonine kinase-type receptor family, TNF receptor family, G protein-coupled receptor family, GPI-anchored receptor family, tyrosine phosphatase-type receptor family, cell adhesion receptor family, and hormone receptor family, wherein in each of said kinds of receptors, said ligand-binding domain derives from a different receptor, and binding of a ligand to the ligand-binding domain induces signal transduction through the signal-transducing domain; (ii) contacting a test sample with said composition comprising cells expressing two or more kinds of receptors; and (iii) detecting binding of said test sample to at least one of said two or more kinds of receptors by detecting a change in a detection marker selected from the group consisting of proliferation activity of the cells, phosphorylation of the receptor or downstream substrate proteins, dephosphorylation of the receptor or downstream substrate proteins, change in cAMP level, change in Ca 2+ level, and induction of downstream gene expression, wherein said change is induced by signal transduction through said common signal-transducing domain.