Separation of P/C- and U-type inactivation pathways in Kv1.5 potassium channels.

P/C-type inactivation of Kv channels is thought to involve conformational changes in the outer pore of the channel, culminating in a partial constriction of the selectivity filter. Recent studies have identified a number of phenotypic differences in the inactivation properties of different Kv channels, including different sensitivities to elevation of extracellular K+ concentration, and different state dependencies of inactivation. We have demonstrated that an alternatively spliced short form of Kv1.

N-terminal PDZ-binding domain in Kv1 potassium channels.

We have investigated the interactions of prototypical PDZ domains with both the C- and N-termini of Kv1.5 and other Kv channels. A combination of in vitro binding and yeast two-hybrid assays unexpectedly showed that PDZ domains derived from PSD95 bind both the C- and N-termini of the channels with comparable avidity.