Abstract: The invention relates, in part, to methods useful in identifying molecules, that bind TRPM4b, which modulate TRPM4b ion channel activity, and/or which alter expression of TRPM4b within cells. The TRPM4b channels as described herein comprise TRPM4b polypeptides, which are in turn encoded by TRPM4b nucleic acids. The ion channels described herein are preferably formed in HEK-293 cells and comprise one or more novel TRPM4b polypeptides, which exhibit one or more of the unique TRPM4b properties described herein.

Abstract: The present invention relates to the identification and isolation of a novel family of ADP ribose (“ADPR) regulated calcium transmembrane channel polypeptides designated herein as “LTRPC2” (Long Transient Receptor Potential Channel). Channels comprising these polypeptides open in response to concentrations of cytoplasmic ADPR in the micromolar range, exhibit enhanced activity in the presence of high intracellular levels of calcium, and do not respond to depletion or reduction in intracellular calcium stores. The invention further relates to the methods of utilizing LTRPC2 for binding, and the methods for modulating LTRPC2 activity and for measuring LTRPC2 permeability. The invention further relates to the methods of modulating expression of LTRPC2.