Method for screening agents for the treatment of diabetes

A process for manufacturing a pharmaceutical composition for treating diabetes, comprising:

• bringing a cell which is transformed with an expression vector comprising at least one polynucleotide encoding at least one polypeptide and is expressing the at least one polypeptide, a cell membrane thereof, or the at least one polypeptide, into contact with an agent to be tested, in the presence of a labeled agonist of the at least one polypeptide, the at least one polypeptide being
• (1) a polypeptide having the amino acid sequence of SEQ ID NO.:
• 2 or 16, or
• (2) a polypeptide having an amino acid sequence in which 1 to 10 amino acids are deleted, substituted, and/or added in the amino acid sequence of SEQ ID NO.:
• 2 or 16, or having an amino acid sequence having a 90% or more homology with the amino acid sequence of SEQ ID NO.:
• 2 or 16, and exhibiting
• (a) an activity of promoting insulin secretion from pancreatic β cells by activation under a high glucose concentration and/or
• (b) an activity of increasing an amount of intracellular cAMP in the cells by activation;
• analyzing a change of an amount of the labeled agonist which binds to the cell, the cell membrane thereof, or the at least one polypeptide;
• and preparing a pharmaceutical composition containing the analyzed agent.

A method for treating diabetes, comprising administering to a subject in need thereof an agent that activates

• (1) a polypeptide having the amino acid sequence of SEQ ID NO.:
• 2 or 16, or
• (2) a polypeptide having an amino acid sequence in which 1 to 10 amino acids are deleted, substituted, and/or added in the amino acid sequence of SEQ ID NO.:
• 2 or 16, or having an amino acid sequence having a 90% or more homology with the amino acid sequence of SEQ ID NO.:
• 2 or 16, and exhibiting
• (a) an activity of promoting insulin secretion from pancreatic β cells by activation under a high glucose concentration and/or
• (b) an activity of increasing an amount of intracellular cAMP in the cells by activation;
• in an effective amount thereof.

A method for promoting insulin secretion, comprising administering to a subject in need thereof an agent that activates

• a polypeptide having the amino acid sequence of SEQ ID NO.:
• 2 or 16, or
• a polypeptide having an amino acid sequence in which 1 to 10 amino acids are deleted, substituted, and/or added in the amino acid sequence of SEQ ID NO.:
• 2 or 16, or having an amino acid sequence having a 90% or more homology with the amino acid sequence of SEQ ID NO.:
• 2 or 16, and exhibiting
• an activity of promoting insulin secretion from pancreatic β cells
• by activation under a high glucose concentration and/or
• an activity of increasing an amount of intracellular cAMP in the cells by activation;
• in an effective amount thereof.