Calcium-activated potassium channel subunit alpha-1 (KCNMA1) (BK channel)

The Calcium-activated potassium channel subunit alpha-1, frequently referred to as SLO-1 or the BK channel, is a large-conductance ion channel that plays a pivotal role in regulating membrane excitability across various tissues (UniProt: Q12791). It is distinctively activated by both membrane depolarization and increases in intracellular calcium levels, acting as a feedback mechanism to limit cell activation (NCBI Gene: 3778). In the central nervous system, SLO-1 regulates neurotransmitter release and the frequency of action potential firing, while in peripheral tissues, it mediates the relaxation of vascular, airway, and bladder smooth muscle (PubMed: 24719331). The channel is a validated therapeutic target in veterinary medicine, where the drug emodepside acts on nematode SLO-1 to cause paralysis (PubMed: 15530334). In human medicine, dysregulation of this channel is associated with conditions such as epilepsy, paroxysmal dyskinesia, and hypertension (PubMed: 15475978). Pharmacological modulation of SLO-1 holds potential for treating asthma and overactive bladder, though achieving tissue specificity remains a significant challenge for drug development (PubMed: 21841152). Current research focuses on developing selective activators for cardiovascular diseases and inhibitors for specific neurological disorders. The widespread expression of the channel across the body necessitates careful consideration of off-target effects during therapeutic intervention.

Other names

SLO1Maxi-KBKCaKCa1.1Slo-1hSloKCNMA1Large conductance calcium-activated potassium channel

The SLO-1 channel acts as a high-conductance potassium pore that opens in response to membrane depolarization and increased intracellular calcium, leading to potassium efflux and membrane hyperpolarization. Drugs targeting this channel function as either openers (activators) that promote hyperpolarization to reduce cellular excitability or blockers (inhibitors) that prevent potassium efflux to increase excitability (PubMed: 21841152).