- Peptide AKLRVSYEYTEAEDKS(C), corresponding to amino acid residues 2-17 of rat KCNMB4 (Accession Q9ESK8). Intracellular, N-terminal part.
- Western blot analysis of rat brain membranes:1. Anti-sloβ4 (KCNMB4) Antibody (#APC-061), (1:200).
2. Anti- sloβ4 (KCNMB4) Antibody, preincubated with sloβ4/KCNMB4 Blocking Peptide (#BLP-PC061).
- Rat brain membranes (1:200). Human detrusor smooth muscle (DSM) cells (1:200) (Hristov, K.L. et al. (2011) Am. J. Physiol. 301, C903.).
- Rat brain sections (1:50) (Piwonska, M. et al. (2008) Neuroscience 153, 446.).
- Human detrusor smooth muscle (DSM) cells (1:100) (Hristov, K.L. et al. (2011) Am. J. Physiol. 301, C903.).
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 transmembrane 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 system (CNS).
Functionally, 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 nanomolar concentrations of the well-known inhibitors charybdotoxin and iberiotoxin.
The 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.