Introduction: Intracellular pH (pHi) regulates essentially all aspects of cellular activities. However, it is unknown how endoplasmic reticulum (ER) potassium channels sense pHi. In this study, we investigate the direct effects of pHi on ER potassium channels. Methods: We used channel incorporation into the bilayer lipid membrane method. L-α-phosphatidylcholine, a membrane lipid, was extrac...

Phosphorylation of potassium channels affects their function and plays a major role in regulating cell physiology. Here, we review previous studies of potassium channel phosphorylation, focusing first on studies employing site-directed mutagenesis of recombinant channels expressed in heterologous cells. We then discuss recent mass spectrometric-based approaches to identify and quantify phosphor...

Ion channels lower the energetic barrier for ion passage across cell membranes and enable the generation of bioelectricity. Electrostatic interactions between permeant ions and channel pore helix dipoles have been proposed as a general mechanism for facilitating ion passage. Here, using genetic selections to probe interactions of an exemplar potassium channel blocker, barium, with the inward re...

BACKGROUND Resveratrol is a polyphenolic compound extracted from plants and is also a constituent of red wine. Resveratrol produces relaxation of vascular smooth muscle and may prevent cardiovascular diseases. Although resveratrol has been reported to cause relaxation of the guinea pig gallbladder, limited data are available about the effect of resveratrol on the gallbladder smooth muscle in hu...

ATP-sensitive potassium (KATP) channel openers have a relaxation effect due to the lower cellular membrane potential and inhibit calcium influx. There has been considerable interest in exploring KATP channel openers in the treatment of various diseases such as cardiovascular, cerebrovascular, and urinary system disease and premature labor. The purpose of this study was to synthesize 3,3,6,6-tet...

The selectivity filter of potassium channels, the narrowest segment of the pore, permits only potassium ions to diffuse through the pore. Clarke et al. (2010) now present 11 structures of an inwardly rectifying potassium channel, providing evidence that the selectivity filter functions in channel gating and conformational changes in the cytoplasmic domains correlate with pore opening.

Changes in cellular metabolism in response to pharmacological compounds can be detected using a biosensor known as a microphysiometer, which measures the rate at which cells release acidic metabolites. We have applied this technique to screen for effects of cation channel blockers on the metabolism of a variety of human and murine cell lines. At concentrations sufficient for cation channel bloc...

This study was performed to investigate the action of potassium channel openers on the mechanical activity of detrusor muscle isolated from rats. Detrusor muscle strips, 15 mm in length, were myographied isometrically in an isolated organ bath. P 1060, RP 49356 and BRL 38277, potassium channel activators, reduced the basal tone and diminished the phasic activity of detrusor concentration-depend...

We report a 4-generation Turkish family with 10 affected members presenting with myotonia and potassium- and exercise-induced paralytic attacks. The clinical presentation was neither typical for the chloride channel myotonias Thomsen and Becker nor for the separate sodium channel myotonia entities potassium-aggravated myotonia, paramyotonia congenita, and hyperkalemic periodic paralysis. It is ...

Potassium Channels allow potassium flux and are essential for the generation of electric current acrossexcitable membranes. Potassium Channels are also the targets of various intracellular controlmechanisms; such that the suboptimal regulation of channel function might be related to pathologicalconditions. Realistic studies of ion current in biologic channels present a major challenge for compu...