calcium-activated potassium channel beta subunit

{{Infobox protein family

| Symbol = CaKB

| Name = CaKB

| image = PDB 1jo6 EBI.jpg

| width =

| caption = solution structure of the cytoplasmic n-terminus of the bk beta-subunit kcnmb2

| Pfam = PF03185

| Pfam_clan =

| InterPro = IPR003930

| SMART =

| PROSITE =

| MEROPS =

| SCOP = 1jo6

| TCDB = 8.A.14

| OPM family =

| OPM protein =

| CAZy =

| CDD =

}}

In molecular biology, the calcium-activated potassium channel beta subunit is a family of proteins comprising the beta subunits of calcium-activated potassium channels.

The functional diversity of potassium channels can arise through homo- or hetero-associations of alpha subunits or association with auxiliary cytoplasmic beta subunits. The beta subunit (which is thought to possess 2 transmembrane domains) increases the calcium sensitivity of the BK channel.{{cite journal |vauthors=McManus OB, Helms LM, Pallanck L, Ganetzky B, Swanson R, Leonard RJ | title = Functional role of the beta subunit of high conductance calcium-activated potassium channels | journal = Neuron | volume = 14 | issue = 3 | pages = 645–50 |date=March 1995 | pmid = 7695911 | doi = 10.1016/0896-6273(95)90321-6| s2cid = 6093600 | doi-access = free }} It does this by enhancing the time spent by the channel in burst-like open states. However, it has little effect on the durations of closed intervals between bursts, or on the numbers of open and closed states entered during gating.{{cite journal |vauthors=Nimigean CM, Magleby KL | title = The beta subunit increases the Ca2+ sensitivity of large conductance Ca2+-activated potassium channels by retaining the gating in the bursting states | journal = J. Gen. Physiol. | volume = 113 | issue = 3 | pages = 425–40 |date=March 1999 | pmid = 10051518 | pmc = 2222905 | doi = 10.1085/jgp.113.3.425}}