Patent ID: 9181318
Filing Date: 2015-11-10
Classification: C07K,C12N,C12Q,C12Y,G01N

Abstract:
1. A method of screening a substance regulating insulin secretion from a cell, which comprises: contacting a cell transformed with a polynucleotide encoding a fusion protein of preproinsulin and a luciferase with a test substance, and detecting luminescence of the luciferase to measure a level of insulin secretion, wherein the luciferase is wherein (a) a protein comprising the amino acid sequence of SEQ ID NO: 8; (b) a protein consisting of an amino acid sequence comprising deletion, substitution, insertion and/or addition of 1 to 10 amino acid residues in the amino acid sequence of SEQ ID NO: 8, and having substantially the same activity as a protein consisting of the amino acid sequence of SEQ ID NO: 8; (c) a protein consisting of an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO: 8, and having substantially the same activity as the protein consisting of the amino acid sequence of SEQ ID NO: 8; and, wherein the preproinsulin consists of a signal peptide of preproinsulin and the polypeptide of any one of (i) through (k) below: (i) a polypeptide consisting of the amino acid sequence of SEQ ID NO: 4; (j) a polypeptide comprising a polypeptide consisting of an amino acid sequence comprising deletion, substitution, insertion and/or addition of 1 to 10 amino acid residues in the amino acid sequence of SEQ ID NO: 4, and having an insulin activity; (k) a polypeptide comprising a polypeptide consisting of an amino acid sequence having at least 90% identity to the amino acid sequence of SEQ ID NO: 4, and having an insulin activity; and, wherein the signal peptide of preproinsulin is a polypeptide consisting of the amino acid sequence of SEQ ID NO: 6.