Site-directed mutagenesis identified a region near the amino terminus of the Shaker potassium channel that forms a cytoplasmic domain interacting with the open channel to cause inactivation.
The potassium channels encoded by the Drosophila Shaker gene activate and inactivate rapidly when the membrane potential becomes more positive. Site-directed mutagenesis and single-channel patch-clamp recording were used to explore the molecular transitions that underlie inactivation in Shaker potassium channels expressed in Xenopus oocytes. A region near the amino terminus with an important role in inactivation has now been identified. The results suggest a model where this region forms a cytoplasmic domain that interacts with the open channel to cause inactivation.
Hoshi et al. (Fri,) conducted a other in Shaker potassium channel inactivation. Site-directed mutagenesis was evaluated on Molecular transitions underlying inactivation. Site-directed mutagenesis identified a region near the amino terminus of the Shaker potassium channel that forms a cytoplasmic domain interacting with the open channel to cause inactivation.