Large conductance voltage-and calcium-activated K (BK) channel in health and disease.

Large Conductance Voltage- and Calcium-activated K (BK) channels are transmembrane pore-forming proteins that regulate cell excitability and are also expressed in non-excitable cells. They play a role in regulating vascular tone, neuronal excitability, neurotransmitter release, and muscle contraction. Dysfunction of the BK channel can lead to arterial hypertension, hearing disorders, epilepsy, and ataxia.

Mechanism of voltage sensing in Ca- and voltage-activated K (BK) channels.

In neurosecretion, allosteric communication between voltage sensors and Ca binding in BK channels is crucially involved in damping excitatory stimuli. Nevertheless, the voltage-sensing mechanism of BK channels is still under debate. Here, based on gating current measurements, we demonstrate that two arginines in the transmembrane segment S4 (R210 and R213) function as the BK gating charges.

BK in Double-Membrane Organelles: A Biophysical, Pharmacological, and Functional Survey.

In the 1970s, calcium-activated potassium currents were recorded for the first time. In 10years, this Ca-activated potassium channel was identified in rat skeletal muscle, chromaffin cells and characterized in skeletal muscle membranes reconstituted in lipid bilayers. This calcium- and voltage-activated potassium channel, dubbed BK for "Big K" due to its large ionic conductance between 130 and 300 pS in symmetric K.