COUPLING OF ATP HYDROLYSIS WITH CHANNEL GATING BY PURIFIED, RECONSTITUTED CFTR

The cystic fibrosis transmembrane conductance regulator (CFTR) is a ch loride channel situated on the apical membrane of epithelial cells. Ou r recent studies of purified, reconstituted CFTR revealed that it also functions as an ATPase and that there may be coupling between ATP hyd rolysis and channel gating. Both the ATP turnover rate and channel gat ing are slow, in the range of 0.2 to 1 s(-1), and both activities are suppressed in a disease-causing mutation situated in a putative nucleo tide binding motif. Our future studies using purified protein will be directed toward understanding the structural basis and mechanism for c oupling between hydrolysis and channel function.