The present invention relates to a novel 1,957 amino acid tetrodotoxin-insensitive voltage-gated sodium channel specifically located in mammalian sensory neurons. Nucleic acid sequences coding for the novel sodium channel, vectors, host cells and methods of identifying modulators of the novel sodium channel for use in treatment of pain are also provided.
1. An isolated nucleic acid that specifically hybridises under moderate stringency conditions of 50-60° C., 5×SSC, 30 minutes to the complement of the coding sequence set forth in SEQ ID NO: 1;
wherein said isolated nucleic acid encodes the voltage-gated tetrodotoxin insensitive sodium channel of SEQ ID NO: 4.
2. An isolated nucleic acid that specifically hybridises under moderate stringency conditions of 50-60° C., 5×SSC, 30 minutes to the complement of the coding sequence set forth in SEQ ID NO: 1;
wherein said isolated nucleic acid encodes the voltage-gated tetrodotoxin insensitive sodium channel of SEQ ID NO: 6.
3. An isolated nucleic acid that specifically hybridises under moderate stringency conditions of 50-60° C., 5×SSC, 30 minutes to the complement of the coding sequence set forth in SEQ ID NO: 1;
wherein said isolated nucleic acid encodes the voltape-gated tetrodotoxin insensitive sodium channel of SEQ ID NO: 8.
4. An isolated nucleic acid that snecifically hybridises under moderate stringency conditions of 5-60° C., 5×SSC, 30 minutes to the complement of the coding sequence set forth in SEQ ID NO: 1;
wherein said isolated nucleic acid encodes the voltage-gated tetrodotoxin insensitive sodium channel of SEQ ID NO: 2.
5. A vector comprising a nucleic acid sequence of claim 4 .
6. An isolated host cell comprising a vector of claim 5 .
7. An isolated host cell transformed or transfected with a nucleic acid sequence of claim 4 .
8. A method of making a sodium channel polypeptide comprising culturing a host cell according to claim 6 or claim 7 under conditions suitable for expression of a sodium channel polypeptide and purifying the expressed polypeptide.