Eukaryotic mechanosensory transduction channel

Abstract

The present invention provides, for the first time, nucleic acids encoding a eukaryotic mechanosensory transduction channel (MSC) protein. The proteins encoded by these nucleic acids form channels that can directly detect mechanical stimuli and convert them into electrical signals. These nucleic acids and the proteins they encode can be used as probes for sensory cells in animals, and can be used to diagnose and treat any of a number of human conditions involving inherited, casual, or environmentally-induced loss of mechanosensory transduction activity.

What is claimed is:  
     
         1 . An isolated nucleic acid encoding a mechanosensory transduction protein, the protein having at least one of the following characteristics: 
 (i) comprising greater than about 70% amino acid sequence identity to SEQ ID NO:2 or SEQ ID NO:4;    (ii) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9; or    (iii) specifically binding to polyclonal antibodies generated against a polypeptide comprising an amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4;    wherein the protein does not comprise the amino acid sequence of SEQ ID NO:6.    
     
     
         2 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4.  
     
     
         3 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid comprises a nucleotide sequence of SEQ ID NO:1 or SEQ ID NO:3 but not SEQ ID NO:5.  
     
     
         4 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid selectively hybridizes under moderately stringent wash conditions to a nucleic acid comprising a nucleotide sequence of SEQ ID NO:1 or SEQ ID NO:3.  
     
     
         5 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid selectively hybridizes under stringent wash conditions to a nucleic acid comprising a nucleotide sequence of SEQ ID NO:1 or SEQ ID NO:3 but not SEQ ID NO:5.  
     
     
         6 . The isolated nucleic acid of  claim 1 , wherein the nucleic acid is amplified by primers that selectively hybridize under stringent wash conditions to a nucleic acid having the same sequence as degenerate primer sets encoding an amino acid sequence selected from the group consisting of: 
 LDVLIENEQKEV (SEQ ID NO:7);    HHLFGPWAIII (SEQ ID NO:8); and    VLINLLIAMMSDTYQRIQ (SEQ ID NO:9).    
     
     
         7 . An expression cassette comprising the nucleic acid of  claim 1 .  
     
     
         8 . An isolated eukaryotic cell comprising the expression cassette of  claim 7 .  
     
     
         9 . An isolated nucleic acid encoding an extracellular domain of a mechanosensory transduction protein, the extracellular domain comprising greater than about 70% amino acid sequence identity to an extracellular domain of SEQ ID NO:2 or SEQ ID NO:4, wherein the extracellular domain does not comprise an extracellular domain of SEQ ID NO:6.  
     
     
         10 . The nucleic acid of  claim 7 , wherein the extracellular domain is fused to a heterologous polypeptide, forming a chimeric polypeptide.  
     
     
         11 . The nucleic acid of  claim 8 , wherein the extracellular domain comprises the amino acid sequence of an extracellular domain of SEQ ID NO:2 or SEQ ID NO:4.  
     
     
         12 . An isolated mechanosensory transduction protein, the protein having at least one of the following characteristics: 
 (i) comprising greater than about 70% amino acid sequence identity to SEQ ID NO:2 or SEQ ID NO:4;    (ii) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9; or    (iii) specifically binding to polyclonal antibodies generated against a polypeptide comprising an amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4;    wherein the protein does not comprise the amino acid sequence of SEQ ID NO:6.    
     
     
         13 . The isolated mechanosensory transduction protein of  claim 12 , wherein the protein comprises the amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4.  
     
     
         14 . An isolated polypeptide comprising an extracellular domain of a mechanosensory transduction protein, the extracellular domain comprising greater than about 70% amino acid sequence identity to an extracellular domain of SEQ ID NO:2 or SEQ ID NO:4, wherein the extracellular domain does not comprise the amino acid sequence of an extracellular domain of SEQ ID NO:6.  
     
     
         15 . The isolated polypeptide of  claim 14 , wherein the extracellular domain is fused to a heterologous polypeptide, forming a chimeric polypeptide.  
     
     
         16 . The isolated polypeptide of  claim 14 , wherein the extracellular domain comprises the amino acid sequence of an extracellular domain of SEQ ID NO:2 or SEQ ID NO:4.  
     
     
         17 . An antibody that selectively binds to a mechanosensory transduction protein, the protein having at least one of the following characteristics: 
 (i) comprising greater than about 70% amino acid sequence identity to SEQ ID NO:2 or SEQ ID NO:4;    (ii) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9; or    (iii) specifically binding to polyclonal antibodies generated against a polypeptide comprising an amino acid sequence of SEQ ID NO:2 or SEQ ID NO:4;    wherein the protein does not comprise the amino acid sequence of SEQ ID NO:6.    
     
     
         18 . A method for identifying a compound that modulates mechanosensory receptor activity in eukaryotic cells, the method comprising the steps of: 
 (i) contacting the compound with a mechanosensory receptor protein, the protein having at least one of the following characteristics: 
 (a) comprising greater than about 70% amino acid sequence identity to a sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:4, and SEQ ID NO:6;  
 (b) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9; or  
 (c) specifically binding to polyclonal antibodies generated against a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:4, and SEQ ID NO:6; and  
   (ii) determining the functional effect of the compound on the mechanosensory receptor protein.    
     
     
         19 . The method of  claim 18 , wherein the mechanosensory receptor protein is expressed in a eukaryotic cell or cell membrane.  
     
     
         20 . The method of  claim 19 , wherein the functional effect is determined by detecting a change in the mechanoreceptor potential of the cell or cell membrane.  
     
     
         21 . The method of  claim 19 , wherein the functional effect is determined by detecting a change in an intracellular ion concentration.  
     
     
         22 . The method of  claim 21 , wherein the ion is selected from the group consisting of K +  and Ca 2+ .  
     
     
         23 . The method of  claim 18 , wherein the protein comprises an amino acid sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:4, and SEQ ID NO:6.  
     
     
         24 . The method of  claim 18 , wherein the protein is recombinant.  
     
     
         25 . The method of  claim 18 , wherein the functional effect is a physical interaction with the receptor protein.  
     
     
         26 . A method of genotyping a human for a mechanosensory transduction channel locus, the method comprising detecting a mutation in a nucleic acid encoding a mechanosensory transduction protein in the human, the protein having at least one of the following characteristics: 
 (a) comprising greater than about 70% amino acid sequence identity to a sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:4, and SEQ ID NO:6;    (b) comprising an amino acid sequence selected from the group consisting of SEQ ID NO:7, SEQ ID NO:8, and SEQ ID NO:9; or    (c) specifically binding to polyclonal antibodies generated against a polypeptide comprising an amino acid sequence selected from the group consisting of SEQ ID NO:2, SEQ ID NO:4, and SEQ ID NO:6;    wherein the mutation introduces a premature stop codon into the nucleic acid upstream of the region encoding the transmembrane domain region of the protein, or is a missense mutation removing a cysteine residue between transmembrane segments 4 and 5 of the protein.