• KCa1.1

    Single channel currents of BK channels as recorded from CHO cells in the cell attached mode on the Port-a-Patch

KCa1.1 | BK | Maxi-K | Calcium-activated Potassium Channel Subunit Alpha-1

Calcium-activated Potassium channels

Today, eight  human calcium-activated channels are known: KCa1.1 (also known as BK or Maxi-K), KCa2.1 (also known as SK1), KCa2.2 (also known as SK2), KCa2.3 (also known as SK3) , KCa3.1 (also known as IK or SK4), KCa4.1, KCa4.2, KCa5.1

KCa channels are made up of two different subunits, alpha and beta. The alpha subunit contains six or seven trans-membrane regions and forms homo- or heter-tetramers. The beta subunit has a regulative function and contains 2 trans-membrane regions.

This family of ion channels is, for the most part, activated by intracellular Ca2+. However, some of these channels (the KCa4 and KCa5 channels) are responsive instead to other intracellular ligands, such as Na+, Cl, and pH. Furthermore, multiple members of family are both ligand and voltage activated.

Data and Applications

Neurons (Primary Hippocampal Granule Cell) - Current Traces

icon pap   Port-a-Patch data and applications:

Recordings from acutely isolated hippocampal granule cells show BK- and CaV currents. Whole cell currents were obtained by depolarizing voltage pulses from a holding potential of −80 mV.

KCa1.1 (BK) - Single Channel Recordings

application kca11 1

icon pap   Port-a-Patch data and applications:

Single channel recordings of BK channels as recorded from CHO cells in the cell attached mode at +60 mV (top), +40 mV (middle) and 0 mV (lowest trace).


KCa1.1 (BK) - Intracellular Second Messengers

icon pap   Port-a-Patch data and applications:p24 2 InternalApp

Currents mediated by BK channels expressed in CHO cells were studied using the Internal Perfusion System. Currents were elicited by a voltage step from -80 mV to +80 mV before and after adding an internal solution containing a higher concentration of free Ca2+.

KCa1.1 (BK) - Activation by Internal Calcium

icon pl   Patchliner data and applications:

BK vertical

Top: BK (KCa1.1) current voltage relationships in a single cell showing effects of changing the intracellular free Ca2+ concentration (15 nM, n = 9; 108 nM, n = 11; 316 nM, n = 11).

Bottom: Comparison of BK (KCa1.1) current voltage relationships obtained on a conventional patch clamp setup (closed circles, n = 10) and on the Patchliner (open circles, n = 11).
Data are taken from Milligan C.J. et al., Nature Protocols, 2009, 4(2), 244-255.



2015 - "Organellar Transporters and Ion Channels - How to access their electrophysiology by using the SURFE2R technology and Planar Patch Clamp"

Icon N1   SURFE²R N1 and   icon sp96   SyncroPatch 96 (a predecessor model of the SyncroPatch 384PE) and   icon pap   Port-a-Patch poster, GRC - Organellar Channels and Transporters 2015   logo pdf   (1.6 MB)




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