Cloned glucagon-like peptide-2 receptors

Abstract

The invention relates to nucleotides and amino acid sequences encoding Glucagon-like peptide-2 receptors, recombinant host cells transformed with such nucleotides, and methods of using the same in drug screening and related applications.

1 .- 16 . (canceled) 
     
     
         17 . An isolated polynucleotide which encodes a chimeric GLP-2 receptor, comprising:
 an N-terminal extracellular domain of a GLP-2 receptor; and   at least one domain of a G-protein coupled receptor, wherein the G-protein coupled receptor is not the GLP-2 receptor, and wherein the domain is selected from at least one of a transmembrane domain or a C-terminal intracellular domain.   
     
     
         18 . The isolated polynucleotide of  claim 17 , wherein the GLP-2 receptor is selected from a human GLP-2 receptor comprising the amino acid sequence of amino acids 67-553 of SEQ ID NO: 12, and a GLP-2 receptor which is at least 95% identical to amino acids 26-553 of SEQ ID NO: 12 and which exhibits the functional characteristic of selectively binding GLP-2. 
     
     
         19 . The isolated polynucleotide of  claim 18 , wherein the GLP-2 receptor is the human GLP-2 receptor comprising the amino acid sequence of amino acids 67-553 of SEQ ID NO: 12, and wherein the N-terminal extracellular domain of the GLP-2 receptor comprises the amino acid sequence of amino acids 67-180 of SEQ ID NO: 12. 
     
     
         20 . The isolated polynucleotide of  claim 19 , wherein the at least one domain of the G-protein coupled receptor is the transmembrane domain. 
     
     
         21 . The isolated polynucleotide of  claim 20 , wherein the transmembrane domain of the G-protein coupled receptor is an analog of a transmembrane domain of the GLP-2 receptor. 
     
     
         22 . The isolated polynucleotide of  claim 21 , wherein the transmembrane domain of the GLP-2 receptor comprises an amino acid sequence, wherein the amino acid sequence is selected from at least one of amino acids 181-203 of SEQ ID NO: 12, amino acids 211-230 of SEQ ID NO: 12, amino acids 262-285 of SEQ ID NO: 12, amino acids 300-321 of SEQ ID NO: 12, amino acids 339-362 of SEQ ID NO: 12, amino acids 386-405 of SEQ ID NO: 12, or amino acids 422-441 of SEQ ID NO: 12. 
     
     
         23 . The isolated polynucleotide of  claim 19 , wherein the at least one domain of the G-protein coupled receptor is the C-terminal intracellular domain. 
     
     
         24 . The isolated polynucleotide of  claim 23 , wherein the C-terminal intracellular domain of the G-coupled receptor is an analog of a C-terminal intracellular domain of the GLP-2 receptor. 
     
     
         25 . The isolated polynucleotide of  claim 24 , wherein the C-terminal intracellular domain of the GLP-2 receptor comprises the amino acid sequence of amino acids 442-553 of SEQ ID NO: 12. 
     
     
         26 . The isolated polynucleotide of  claim 19 , wherein the N-terminal extracellular domain of the GLP-2 receptor comprises at least one amino acid substitution. 
     
     
         27 . The isolated polynucleotide of  claim 26 , wherein the at least one amino acid substitution comprises one or more of:
 at least one amino acid substitution at one of the following amino acid positions of SEQ ID NO: 12: 78, 82, 85, 88-91, 110, 127, 130, 146, 149, 171, or 176; or   at least one conservative amino acid substitution at one of the following amino acid positions of SEQ ID NO: 12: 70, 74, 81, 102, 126, 156, or 166.   
     
     
         28 . The isolated polynucleotide of  claim 21 , wherein the at least one domain of the G-protein coupled receptor comprises at least one amino acid substitution. 
     
     
         29 . The isolated polynucleotide of  claim 19 , further comprising an expression controlling element. 
     
     
         30 . A method for identifying GLP-2 receptor ligands comprising:
 incorporating the isolated polynucleotide of  claim 29  within a cell;   incubating a candidate ligand with the cell or with a membrane preparation obtained therefrom; and   determining whether binding between the N-terminal extracellular domain of the GLP-2 receptor and the candidate ligand has occurred.   
     
     
         31 . The method of  claim 30 , wherein the cell is a mammalian cell.