Electrophysiological Approach to Studying CFTR

Cystic fibrosis transmembrane conductance regulator (CFTR) is aphosphorylation and ATP-dependent Cl∼ channel. It is predominantly expressed in the apical membrane of epithelial cells. The presence and function of CFTR in a cell is sensitively measured using electrophysiological techniques. The patch clamp technique is the most frequently used method to measure CFTR in single cells or in isolated patches of cell membrane. A key step for the successful recording of CFTR is its identification and distinction from other Cl∼ channels. In patch clamp recordings this is done by probing for physiological, pharmacological, or biophysical characteristics of the channel. This chapter describes first, how to successfully record CFTR currents using the patch clamp technique. Second, it focuses on current noise analysis as a useful tool to investigate the regulation of CFTR activity.