The present invention provides novel polynucleotides encoding LTRPC3 polypeptides, fragments and homologues thereof. The present invention also provides polynucleotides encoding variants and splice variants of LTRPC3 polypeptides, LTRPC3b, LTRPC3c, LTRPC3d, LTRPC3e, and LTRPC3f, respectively. Also provided are vectors, host cells, antibodies, and recombinant and synthetic methods for producing the novel LTRPC3, LTRPC3b, LTRPC3c, LTRPC3d, LTRPC3e, and LTRPC3f polypeptides. The invention further relates to diagnostic and therapeutic methods for applying these novel LTRPC3, LTRPC3b, LTRPC3c, LTRPC3d, LTRPC3e, and LTRPC3f polypeptides to the diagnosis, treatment, and/or prevention of various diseases and/or disorders related to these polypeptides. The invention further relates to screening methods for identifying agonists and antagonists of the polynucleotides and polypeptides of the present invention.