This family consists of at least 10 genes, each of which has several splice variants. Most members of the family are expressed in the luminal membrane of epithelial cells. Characterization of anion transport by three members has revealed that all function as Cl-/HCO3- exchangers, suggesting that SLC26 transporters are responsible for the luminal Cl-/HCO3- exchange activity. The SLC26 transporters are activated by the CF transmembrane conductance regulator and activate it in turn, leading to a model in which these molecules act together to mediate epithelial Cl- absorption and HCO3- secretion.
The book includes chapters on the transport of other molecules by the SLC26 family, including oxalate in the kidney and sugars in cochlear hair cells amongst others. It also describes recent discoveries that most SLC26 transporters bind to scaffold proteins and that they all contain a conserved domain predicted to participate in protein-protein interactions. These suggest the SLC26 transporters exist in complexes with other Cl- and HCO3- transporters, and possibly other regulatory proteins. This book explores the functional role of these interactions, leading to better understanding of transepithelial fluid and electrolyte secretion and the diseases associated with it.