While most large-conductance, calcium-, and voltage-activated potassium channels (BK or Maxi-K type) are blocked by the scorpion venom iberiotoxin, the so-called "type II" subtype has the property of toxin resistance. This property is uniquely mediated by channel assembly with one member of the BK accessory β subunit family, the neuron-enriched β4 subunit. This review will focus on current unde...

1. Postnatal development of a large conductance Ca(2+)-activated K+ channel (BK channel) was investigated in neocortical infragranular pyramidal neurons with inside-out and outside-out patchclamp configurations. Neurons were acutely isolated from slices of 1- to 28-day-old rats (P1-P28) by using a vibrating glass probe after preincubation with low concentrations of enzymes. Patch membrane area ...

The molecular components of the large-conductance Ca(2+)-activated K(+) channels that are functionally expressed in mitochondria (mitoK(Ca)) in cardiac myocytes have not been identified. Our experimental results show that the transcript corresponding to the large-conductance Ca(2+)-activated K(+) channel beta1-subunit (BK-beta1) is substantially expressed in mammalian heart. A yeast two-hybrid ...

Both bovine and rat adrenal chromaffin cells have served as pioneering model systems in cellular neurophysiology, including in the study of large conductance calcium- and voltage-dependent K(+) (BK) channels. We now report that while BK channels dominate the outward current profile of both species, specific gating properties vary widely across cell populations, and the distributions of these pr...

At first glance, many aspects of physiology appear to function like a Rube Goldberg machine, using convo-luted, over-engineered components to perform simple tasks. Then, we remember that any given physiological system must operate within strict bounds despite exposure to a broad range of environments and behavioral scenarios. This perspective allows elegance and power to emerge from the inheren...

A signature feature of large conductance, calcium-and voltage-activated K + channels (now usually termed " BK " channels) is their dual regulation by two physiological signals, cytosolic Ca 2+ and membrane voltage. This dual-sensing capacity of BK channels distinguishes them from other voltage-dependent K + channels in terms of the physiological roles they can play, allowing their voltage-sensi...

Ethanol alters BK (slo1) channel function leading to perturbation of physiology and behavior. Site(s) and mechanism(s) of ethanol-BK channel interaction are unknown. We demonstrate that ethanol docks onto a water-accessible site that is strategically positioned between the slo1 calcium-sensors and gate. Ethanol only accesses this site in presence of calcium, the BK channel's physiological agoni...

This investigation was conducted to study the relationship between intracellular Ca(2+) and activation of large conductance Ca(2+)-activated K(+) (BK) currents by unoprostone, the first synthetic docosanoid. We used HEK293 cells stably transfected with two BK channel splice variants, one sensitive to unoprostone and the other insensitive. We examined the effects of unoprostone on channel activi...

Large-conductance Ca(2+)-activated potassium (BK) channels are composed of pore-forming alpha-subunits and auxiliary beta-subunits. The alpha-subunits are widely expressed in many cell types, whereas the beta-subunits are more tissue specific and influence diverse aspects of channel function. In the current study, we identified the presence of the smooth muscle-specific beta1-subunit in murine ...