sloβ4 is a member of a family of regulatory β subunits that control the activity of the large conductance Ca2+-activated K+ channel KCa1.1. The family includes four members with a shared topology: two trans-membrane domains, short intracellular N- and C-termini and a large extracellular region.The four members of the family have a distinct tissue distribution with sloβ4 expressed almost exclusively in the central nervous sytem (CNS).nFunctionally, sloβ4 increases the sensitivity of the pore-forming KCa1.1 subunit to Ca2+ and voltage and it also changes its pharmacology. It has been shown that co-expression of sloβ4 with KCa1.1 makes the latter resistant to nM concentrations of the well-known inhibitors Charybdotoxin (#STC-325) and Iberiotoxin (#STI-400).nThe physiological significance of sloβ4 expression in the CNS is not clear, but KCa1.1 channels are likely involved in the regulation of neurotransmitter release in presynaptic terminals
