ECaC: the gatekeeper of transepithelial Ca2+ transport.

The epithelial Ca(2+) channels (ECaCs) are primarily expressed in Ca(2+) transporting epithelia and represent a new family of Ca(2+) channels that belong to the superfamily of transient receptor potential (TRP) channels. Two members, namely ECaC1 and ECaC2, have been identified from kidney and intestine, respectively. These channels are the prime target for hormonal control of active Ca(2+) flux from the urine space or intestinal lumen to the blood compartment. This review covers the distinctive properties of these highly Ca(2+)-selective channels and highlights the implications for our understanding of the process of transepithelial Ca(2+) transport.