Patent ID: 7338772

Claim:
A method for identifying an agonist or antagonist of an SP9155 receptor comprising: (a) contacting a cell expressing human SP9155 receptor or a ligand-binding fragment thereof which receptor or fragment thereof is capable of binding one or more polypeptide ligands comprising an amino acid sequence selected from the group consisting of SEQ ID NOs: 4-11 and 13-18, wherein the carboxy-terminus of each of said polypeptide ligands are amidated, in the presence of a known amount of polypeptide ligand for the human SP9155 receptor or ligand-binding fragment thereof, wherein said polypeptide ligand comprises an amino acid sequence selected from the group consisting of SEQ ID NOs: 4-11 and 13-18, wherein the carboxy-terminus of said polypeptide ligand is amidated, with a sample to be tested for the presence of said agonist or antagonist; and (b) measuring calcium mobilization by the cell; whereby the sample is identified as containing an antagonist by measuring substantially reduced calcium mobilization compared to what would be measured in the absence of the sample and whereby the sample is identified as containing an agonist by measuring substantially increased calcium mobilization compared to what would be measured in the absence of the sample.