Extracellular acidification is known to decrease the conductance of many voltage-gated potassium channels. In the present study, we investigated the mechanism of H(+)(o)-induced current inhibition by taking advantage of Na(+) permeation through inactivated channels. In hKv1.5, H(+)(o) inhibited open-state Na(+) current with a similar potency to K(+) current, but had little effect on the amplitu...

The sulphonylurea receptor (SUR) is a member of the ATP-binding cassette (ABC) family of membrane proteins. It functions as the regulatory subunit of the ATP-sensitive potassium (KATP) channel, which comprises SUR and Kir6.x proteins. Here, we review data demonstrating functional differences between the two nucleotide binding domains (NBDs) of SUR1. In addition, to explain the structural basis ...

Microglia, the resident immune cells of the brain, are important determinants of CNS inflammation. They play defense in the healthy brain, but microglial activation can also lead to neuronal injury or death. The microglial potassium channel Kv1.3 is involved in microglial proliferation and in the respiratory burst that generates reactive oxygen species such as superoxide; thus Fordyce et al. ex...

What is the moving part that switches an ion channel's current on and off? In this issue of Neuron del Camino and Yellen (2001) exploit scanning cysteine mutagenesis and sulfhydryl reagents to show that the intracellular end of the S6 helices forms a mechanical gate for the Shaker potassium channel.

The molecular basis of K+ channel function is universally conserved. K+ channels allow K+ flux and are essential for the generation of electric current across excitable membranes. K+ channels are also the targets of various intracellular control mechanisms, such that the suboptimal regulation of channel function might be related to pathological conditions. Because of the fundamental role of K+ ...