Molecular Cloning, Tissue Distribution, and Chromosomal Mapping of the Human Epithelial Ca2+ Channel (ECAC1)

Functional and morphological analyses indicated that the epithelial Ca2+ channel (ECaC), which was recently cloned from rabbit kidney, exhibits the defining properties for being the gatekeeper in transcellular Ca2+ (re)absorption. Its human homologue provides, therefore, a molecular basis for achieving a better understanding of Ca2+ mal(re)absorption. By applying the RACE technique, the full-length cDNA of human ECaC (HGMW-approved symbol ECAC1) was obtained. It consisted of 2772 bp with an open reading frame of 2187 bp encoding a protein of 729 amino acids with a predicted molecular mass of 83 kDa. Phylogenetic analysis indicated that this highly selective Ca2+ channel exhibits a low level of homology (