Analysis of ion channel mutants is a widely used approach for dissecting ion channel function and for characterizing the mechanisms of action of channel-directed modulators. Expression of functional potassium channels in potassium-uptake-deficient yeast together with genetic selection approaches offers an unbiased, high-throughput, activity-based readout that can rapidly identify large numbers ...

In the present study, we describe the existence of a large-conductance Ca²⁺-activated potassium (BKCa) channel in the mitochondria of the human endothelial cell line EA.hy926. A single-channel current was recorded from endothelial mitoplasts (i.e., inner mitochondrial membrane) using the patch-clamp technique in the mitoplast-attached mode. A potassium-selective current was recorded with a mean...

T he sites in the central nervous system where inhaled anesthetics exert their clinical effects remain to be defined. During the past two decades, most investigators in the field have shifted away from a nonspecific plasma membrane lipid site of action towards direct interactions with membrane proteins or even globular proteins. Currently, favored targets include ligand-gated ion channels, such...

We studied the potassium channel in the basolateral membrane of the rat proximal convoluted tubule as affected by cyclosporine A. Proximal convoluted tubules were dissected from the rat kidney under a stereoscopic microscope, without a preliminary enzyme treatment. The standard configuration for single-channel tight seal patch-clamp technique was used to record channel currents. A small conduct...

Small conductance Ca(2+)-activated potassium channels (SK channels) distributing in the nervous system play an important role in learning, memory and synaptic plasticity. Most pharmacological properties of them are determined by short-chain scorpion toxins. Different from most voltage-gated potassium channels and large-conductance Ca(2+)-activated potassium channels, SK channels are only inhibi...

The discovery of the renal outer medullary K+ channel (ROMK, K(ir)1.1), the founding member of the inward-rectifying K+ channel (K(ir)) family, by Ho and Hebert in 1993 revolutionized our understanding of potassium channel biology and renal potassium handling. Because of the central role that ROMK plays in the regulation of salt and potassium homeostasis, considerable efforts have been invested...

The recently determined structure of a mammalian voltage-gated potassium channel has important implications for our understanding of voltage-sensing and gating mechanisms in channels. It is also the first crystal structure of an overexpressed eukaryotic membrane protein.