Functional Interactions of HCO3- with Cystic Fibrosis Transmembrane Conductance Regulator

Disruption of normal cystic fibrosis transmembrane conductance regulator-(CFTR)-mediated Cl- transport is associated with cystic fibrosis (CF). CFTR is also required for HCO3- transport in many tissues such as the lungs, gastro-intestinal tract, and pancreas, although the exact role CFTR plays is uncertain. Given the importance of CFTR in HCO3- transport by so many CF-affected organ systems, it is perhaps surprising that relatively little is known about the interactions of HCO3-ions with CFTR. We have used patch clamp recordings from native pancreatic duct cells to study HCO3- permeation and interaction with CFTR. Ion selectivity studies shows that CFT