Galanin receptor protein, production and use thereof

Abstract

Galanin receptor proteins, production and use thereof including screening of galanin receptor agonists and antagonists are provided. Galanin receptor proteins, etc. or salts thereof, partial peptides thereof, DNAs coding for the above galanin receptor protein, processes for producing the above receptor protein, methods of screening for a galanin receptor agonist and/or antagonist or screening kits therefor, agonist and/or antagonist compounds or salts thereof obtained by the above screening method or the screening kit, pharmaceutical compositions containing the above compound or its salt, and antibodies against the above receptor protein are provided. It is allowable to efficiently screen a galanin receptor agonist or antagonist by using the galanin receptor protein, the partial peptide thereof, the galanin receptor protein-encoding DNA, the receptor protein-containing cell or its membrane fraction. The pharmaceuticals thus screened or characterized permits various applications including prophylactic and/or therapeutic treatments against a variety of diseases, e.g., stomach ulcer, diabetes, Alzheimer's disease, dementia, etc. and a sedative.

What is claimed is:  
     
         1 . A galanin receptor protein comprising an amino acid sequence selected from the group consisting of an amino acid sequence represented by SEQ ID NO: 1, SEQ ID NO: 2 and SEQ ID NO: 5 or its substantial equivalent thereto, or a salt thereof.  
     
     
         2 . The receptor protein according to  claim 1 , which is produced by a transformant CHO cell.  
     
     
         3 . An isolated DNA which comprises a nucleotide sequence coding for a galanin receptor protein of  claim 1 .  
     
     
         4 . A vector comprising the DNA according to  claim 3 .  
     
     
         5 . A transformant carrying the vector according to  claim 4 .  
     
     
         6 . The transformant according to  claim 5 , wherein the host cell is a CHO cell.  
     
     
         7 . A process for producing a galanin receptor protein according to  claim 1 , which comprises culturing a transformant of  claim 5  under conditions suitable to express said galanin receptor protein.  
     
     
         8 . A screening method for an agonist or antagonist of a galanin receptor protein according to  claim 1 , which comprises carrying out a comparison between: 
 (i) at least one case where galanin is contacted with at least one component selected from the group consisting of a galanin receptor protein according to  claim 1 , a partial peptide thereof and a mixture thereof, and    (ii) at least one case where galanin together with a compound to be tested is contacted with at least one component selected from the group consisting of a galanin receptor protein according to  claim 1 , a partial peptide thereof and a mixture thereof.    
     
     
         9 . A kit for the screening of one or more agonists or antagonists to a galanin receptor protein according to  claim 1 , which comprises at least one component selected from the group consisting of a galanin receptor protein according to  claim 1 , a partial peptide thereof and a mixture thereof.  
     
     
         10 . An agonist or antagonist of a galanin receptor, which is obtained by the screening method according to  claim 8  or the kit according to claim  9 .