Antibody Recognizing G Protein, and Agent and Kit Using the Same

Abstract

A novel protein (Gm1) includes an amino acid sequence part having a high homology with a domain having a high homology with a GTP binding site and a GTPase site conserved among G protein α subunits and a trimer forming domain conserved among G protein α subunits. The Gm1 protein is involved in signal transduction via a G protein-coupled receptor (GPCR) stimulation. The Gm1 protein is expressed intensively in human brain, thymus, testes, spleen, small intestine, uterus and heart. A method for screening for a substance capable of regulating a cellular signal transduction employs a polynucleotide encoding the Gm1 protein

1 . An antibody which recognizes specifically a protein comprising any amino acid sequence selected from the group consisting of:
 (a) the amino acid sequence represented by SEQ ID NO:1;   (b) an amino acid sequence of a protein involved in a G protein-coupled receptor mediated signal transduction, the protein consisting of an amino acid sequence having a homology of 85% or more with the amino acid sequence represented by SEQ ID NO:1;   (c) the amino acid sequence of SEQ ID NO:25;   (d) the amino acid sequence of SEQ ID NO:26;   (e) an amino acid sequence of a protein involved in a G protein-coupled receptor mediated signal transduction, the protein comprising an amino acid sequence of amino acid Nos. 96 to 126 of SEQ ID NO:1;   (f) an amino acid sequence of a protein involved in a G protein-coupled receptor mediated signal transduction, the protein comprising an amino acid sequence having a homology of 95% or more with an amino acid sequence of amino acid Nos. 96 to 126 of SEQ ID NO:1;   (g) an amino acid sequence of a protein involved in a G protein-coupled receptor mediated signal transduction, the protein comprising at its N-terminal an amino acid sequence of amino acid Nos. 1 to 126 of SEQ ID NO:1; and   (h) an amino acid sequence of a protein involved in a G protein-coupled receptor mediated signal transduction, the protein comprising at its N-terminal an amino acid sequence having a homology of 65% or more with an amino acid sequence of amino acid Nos. 1 to 126 of SEQ ID NO:1.   
     
     
         2 . An agent for regulating a G protein-coupled receptor mediated signal transduction containing as an active ingredient an antibody according to  claim 1 . 
     
     
         3 . A therapeutic or prophylactic agent against a disease caused by a G protein-coupled receptor mediated signal transduction abnormality, wherein an active ingredient of the agent is an antibody according to  claim 1 . 
     
     
         4 . A kit for screening for a substance capable of regulating a signal transduction mediated by a G protein-coupled receptor and a protein that comprises:
 a cell capable of expressing a protein comprising an amino acid sequence selected from SEQ ID NOs: 1, 25 and  26; and      an antibody that specifically binds to the protein.