Patent ID: 8252521

Claim:
A screening method for determining whether a substance of interest is a substance which alters G protein-coupled receptor 40 (GPR40)-mediated cell stimulating activities, comprising the steps of: contacting cells containing a biomembrane containing GPR40 with secretory phospholipase A2 (sPLA2) or a salt thereof in the presence and absence of the substance of interest, wherein said GPR40 comprises (a) a polypeptide comprising the amino acid sequence of SEQ ID NO: 2; (b) a polypeptide consisting of an amino acid sequence having 95% or higher identity to the amino acid sequence of SEQ ID NO: 2; or (c) a polypeptide encoded by a polynucleotide consisting of a nucleotide sequence having 95% or higher identity to the nucleotide sequence of SEQ ID NO: 1, said GPR40 is activated in response to sPLA2; measuring cell stimulating activities by using a reporter-assay system that detects a change in an amount of translation/transcription of a reporter gene; and comparing a result measured in the presence of the substance of interest with a result measured in the absence of the substance of interest, wherein detection of a difference between results measured in the presence and absence of the substance of interest determines that the substance of interest is a candidate substance that alters GPR40-mediated cell stimulating activities.