In mammals, the extracellular calcium concentration is maintained within a narrow range
despite large variations in daily dietary input and body demand. The small intestine and
kidney constitute the influx pathways into the extracellular Ca 2+ pool and, therefore, play a
primary role in Ca 2+ homeostasis. We identified an apical Ca 2+ influx channel, which is
expressed in proximal small intestine, the distal part of the nephron and placenta. This novel
epithelial Ca 2+ channel (ECaC) of 730 amino acids contains six putative membrane …