Module 5: Figure sodium/calcium exchangers
Structure and function of sodium/calcium exchangers.
The organization and operation of the Na+/Ca2+ exchanger (NCX) is shown on the left and the Na+/Ca2+–K+ exchanger (NCKX) is shown on the right. There is a large central cytoplasmic loop, part of which has a site where alternative splicing occurs. NCX also has a Ca2+ regulatory site and a binding site for the exchanger inhibitory peptide (XIP). Both exchangers have two regions (α1 and α2, shown in yellow) containing α repeats that are highly homologous and are thought to be the sites where the cations bind to the exchangers. See the text for further details.