Novartis Found Symp 2006 Jan 01;273:177-86; discussion 186-92, 261-4.

Regulatory interaction between CFTR and the SLC26 transporters.

Abstract
Most epithelia that express CFTR secrete fluid rich in HCO3- and poor in Cl- that is generated by a CFTR-dependent Cl- absorption and HCO3- secretion process that when aberrant leads to human diseases such as cystic fibrosis and congenital chloride diarrhoea. Epithelial Cl- absorption and HCO3- secretion require expression of CFTR and other Cl- and HCO3- transporters in the luminal membrane of the secreting cells. Recent advances in understanding this critical epithelial function revealed that the luminal Cl- and HCO3- transporters are members of the SLC26 family. Characterization of several members of the family reveals that all characterized thus far are electrogenic with an isoform specific Cl-/HCO3- transport stoichiometry. In vivo these transporters exist in a transporting complex with CFTR. The SLC26 transporters and CFTR are recruited to the complex by binding to scaffolds containing PDZ domains. Upon stimulation and PKA-dependent phosphorylation of CFTR R domain, the R domain binds to the SLC26 transporter STAS domain. Interaction of the R and STAS domains results in a marked and mutual activation of CFTR and the SLC26 transporters. The significance of this mode of regulation to epithelial Cl- absorption and HCO3- secretion is obvious.

PubMed ID: 17120768



Species referenced: Xenopus
Genes referenced: cftr slc26a3.1
GO keywords: chloride transmembrane transporter activity [+]

Disease Ontology terms: cystic fibrosis
OMIMs: DIARRHEA 1, SECRETORY CHLORIDE, CONGENITAL; DIAR1 [+]