Novel potassium channel molecules and uses therefor

Abstract

The invention provides isolated nucleic acids molecules, designated TWIK nucleic acid molecules, which encode proteins involved in potassium channel mediated activities. The invention also provides antisense nucleic acid molecules, recombinant expression vectors containing TWIK nucleic acid molecules, host cells into which the expression vectors have been introduced, and nonhuman transgenic animals in which a TWIK gene has been introduced or disrupted. The invention still further provides isolated TWIK proteins, fusion proteins, antigenic peptides and anti-TWIK antibodies. Diagnostic methods utilizing compositions of the invention are also provided.

What is claimed is:  
     
         1 . An isolated nucleic acid molecule selected from the group consisting of: 
 a) a nucleic acid molecule comprising a nucleotide sequence which is at least 60% homologous to the nucleotide sequence of SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:9 the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, or a complement thereof;    b) a nucleic acid molecule comprising a fragment of at least 537 nucleotides of a nucleic acid comprising the nucleotide sequence of SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:9 the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, or a complement thereof;    c) a nucleic acid molecule which encodes a polypeptide comprising an amino acid sequence at least about 60% homologous to the amino acid sequence of SEQ ID NO:5, or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______;    d) a nucleic acid molecule which encodes a fragment of a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or the polypeptide encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, wherein the fragment comprises at least 15 contiguous amino acid residues of the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or the polypeptide encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______; and    e) a nucleic acid molecule which encodes a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, wherein the nucleic acid molecule hybridizes to a nucleic acid molecule comprising SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, or SEQ ID NO:9, under stringent conditions.    
     
     
         2 . The isolated nucleic acid molecule of  claim 1  which is selected from the group consisting of: 
 a) a nucleic acid molecule comprising the nucleotide sequence of SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:9 or the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, or a complement thereof; and  
 b) a nucleic acid molecule which encodes a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______.  
 
     
     
         3 . The nucleic acid molecule of  claim 1  further comprising vector nucleic acid sequences.  
     
     
         4 . The nucleic acid molecule of  claim 1  further comprising nucleic acid sequences encoding a heterologous polypeptide.  
     
     
         5 . A host cell which contains the nucleic acid molecule of  claim 1 .  
     
     
         6 . The host cell of  claim 5  which is a mammalian host cell.  
     
     
         7 . A non-human mammalian host cell containing the nucleic acid molecule of  claim 1 .  
     
     
         8 . An isolated polypeptide selected from the group consisting of: 
 a) a fragment of a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or the polypeptide encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, wherein the fragment comprises at least 15 contiguous amino acids of SEQ ID NO:5 or SEQ ID NO:8 or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______;    b) a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, wherein the polypeptide is encoded by a nucleic acid molecule which hybridizes to a nucleic acid molecule comprising SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:9 under stringent conditions; and    c) a polypeptide which is encoded by a nucleic acid molecule comprising a nucleotide sequence which is at least 60% homologous to a nucleic acid comprising the nucleotide sequence of SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:9 or the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or _______.    d) a polypeptide comprising an amino acid sequence which is at least 60% homologous to the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8, or the polypeptide encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______.    
     
     
         9 . The isolated polypeptide of  claim 8  comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______.  
     
     
         10 . The polypeptide of  claim 8  further comprising heterologous amino acid sequences.  
     
     
         11 . An antibody which selectively binds to a polypeptide of  claim 8 .  
     
     
         12 . A method for producing a polypeptide selected from the group consisting of: 
 a) a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______;    b) a fragment of a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______ wherein the fragment comprises at least 15 contiguous amino acids of SEQ ID NO:5 or SEQ ID NO:8 or the amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______; and    c) a naturally occurring allelic variant of a polypeptide comprising the amino acid sequence of SEQ ID NO:5 or SEQ ID NO:8 or an amino acid sequence encoded by the DNA insert of the plasmid deposited with ATCC as Accession Number ______ or ______, wherein the polypeptide is encoded by a nucleic acid molecule which hybridizes to a nucleic acid molecule comprising SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:7, SEQ ID NO:9 under stringent conditions;    comprising culturing the host cell of  claim 5  under conditions in which the nucleic acid molecule is expressed.    
     
     
         13 . A method for detecting the presence of a polypeptide of  claim 8  in a sample comprising: 
 a) contacting the sample with a compound which selectively binds to the polypeptide; and  
 b) determining whether the compound binds to the polypeptide in the sample to thereby detect the presence of a polypeptide of  claim 8  in the sample.  
 
     
     
         14 . The method of  claim 13 , wherein the compound which binds to the polypeptide is an antibody.  
     
     
         15 . A kit comprising a compound which selectively binds to a polypeptide of  claim 8  and instructions for use.  
     
     
         16 . A method for detecting the presence of a nucleic acid molecule in claim I in a sample comprising: 
 a) contacting the sample with a nucleic acid probe or primer which selectively hybridizes to the nucleic acid molecule; and    b) determining whether the nucleic acid probe or primer binds to a nucleic acid molecule in the sample to thereby detect the presence of a nucleic acid molecule of  claim 1  in the sample.    
     
     
         17 . The method of  claim 16 , wherein the sample comprises mRNA molecules and is contacted with a nucleic acid probe.  
     
     
         18 . A kit comprising a compound which selectively hybridizes to a nucleic acid molecule of  claim 1  and instructions for use.  
     
     
         19 . A method for identifying a compound which binds to a polypeptide of  claim 8  comprising: 
 a) contacting the polypeptide, or a cell expressing the polypeptide with a test compound; and  
 b) determining whether the polypeptide binds to the test compound.  
 
     
     
         20 . The method of  claim 19 , wherein the binding of the test compound to the polypeptide is detected by a method selected from the group consisting of: 
 a) detection of binding by direct detection of test compound/polypeptide binding;    b) detection of binding using a competition binding assay; and    c) detection of binding using an assay for TWIK activity.    
     
     
         21 . A method for modulating the activity of a polypeptide of  claim 8  comprising contacting the polypeptide or a cell expressing the polypeptide with a compound which binds to the polypeptide in a sufficient concentration to modulate the activity of the polypeptide.  
     
     
         22 . A method for identifying a compound which modulates the activity of a polypeptide of  claim 8  comprising: 
 a) contacting a polypeptide of  claim 8  with a test compound; and  
 b) determining the effect of the test compound on the activity of the polypeptide to thereby identify a compound which modulates the activity of the polypeptide.