The invention pertains to nucleic acids encoding a mutT domain-containing polypeptide, including fragments and biologically functional variants thereof. The invention also pertains to therapeutics and diagnostics involving the foregoing polypeptide and nucleic acids and agents that bind the foregoing polypeptide and nucleic acids. The invention also pertains to the identification of a novel mutT domain in human TrpC7, a polypeptide previously described as a putative calcium ion channel. Accordingly, the invention also pertains to methods and compositions for identifying agents useful in modulating mutT domain-mediated calcium or other ion transport in cells expressing a polypeptide comprising a mutT domain and a calcium or other ion channel.
