The Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) is a phosphorylation regulated Cl- channel. In order for the channel to be active it needs to be phosphorylated. Then binding of ATP to intracellular nucleotide binding sites controls the opening and closing of the channel (Zhou et al., 2006).
The internal solutions contained F^-. Regulation of many ion channels does not seem to be affected by the presence of F^- in the intracellular solution, however, that is not true for every ion channel. F^-, for example, has been shown to activate the adenylate cyclase (Eckstein et al., 1979). Forskolin – a commonly used CFTR activator – is known to activate CFTR through activation of the adenylate cyclase. This leads to phosphorylation (and hence activation) of CFTR by protein kinase A (PKA). It would be interesting to see if F^- can be used as a substitute for forskolin in its role as a CFTR activator.
In this report we summarize some preliminary measurements of CFTR currents in the whole cell patch clamp configuration with the Patchliner to obtain insight into the effects of F^- on CFTR currents.