Calcium-Activated Potassium (KCa) Channels

Calcium (Ca2+) -activated potassium channels (KCa) are a group of 6/7-TM ion channels that selectively transport K+ ions across biological membranes. They are broadly classified into three subtypes: SK, IK and BK channels (small, intermediate and big conductance).

Gene Data


Cat No Product Name / Activity
4949 MaxiPost
Potassium channel modulator; exerts subtype-specific effects
4597 NS 8593 hydrochloride
Selective KCa2 (SK) channel negative modulator; inhibits SK currents


Cat No Product Name / Activity
2665 BMS 191011
Potent BKCa (KCa1.1) channel opener
2953 CyPPA
Activator of KCa2.2 and KCa2.3 channels
More potent analog of 1-EBIO (Cat. No. 1041). Activates hKCa3.1/Cl- conductance
1041 1-EBIO
Activator of epithelial KCa channels
4311 GW 542573X
Selective activator of KCa2.1 channels
4788 NS 11021
Activator of BKCa (KCa1.1) channels
3804 NS 1619
Activator of BKCa (KCa1.1) channels
5276 NS 19504
Activator of BKCa (KCa1.1) channels
3895 NS 309
Positive modulator of KCa2 and KCa3.1 channels
3670 SKA 31
Activator of KCa3.1 and KCa2 channels


Cat No Product Name / Activity
1652 Apamin
KCa2 channel blocker (small conductance)
1087 Charybdotoxin
KCa channel blocker (big conductance)
1086 Iberiotoxin
KCa channel blocker (big conductance)
3564 Kaliotoxin
KCa and KV blocker
5571 Lei-Dab 7
High affinity, selective KCa2.2 blocker
4864 NS 6180
Potent KCa3.1 channel blocker
2006 Paxilline
Potent blocker of BKCa (KCa1.1) channels
4617 Penitrem A
Potent and selective BKCa (KCa1.1) channel blocker
2946 TRAM 34
Potent and highly selective KCa3.1 channel blocker
4952 TRAM 39
Potent KCa3.1 blocker
1310 UCL 1684
Highly potent blocker of KCa2
2661 UCL 2077
Slow afterhyperpolarization (sAHP) channel blocker; sub-type selective Kv channel effects

Ca2+-activated potassium channels (KCa) are a group of 6/7-TM ion channels that selectively transport K+ ions across biological membranes. They are broadly classified into three subtypes: SK, IK and BK channels, based on their conductance (small, intermediate and big conductance respectively).

The small conductance KCa channels (KCa2.1, 2.2 and 2.3, also known as SK1, SK2 and SK3 respectively) and the intermediate conductance KCa channel (KCa3.1, also known as SK4) are voltage-insensitive and are activated by Ca2+-calmodulin. Both play important roles in many processes involving Ca2+-dependent signaling in both electrically excitable and non-excitable cells. KCa3.1 regulates the activation, proliferation and migration of cells such as mast cells, T cells and airway smooth muscle cells; consequently, it may be a useful therapeutic target for the treatment of asthma.

The BK family of KCa channels (also known as Slo or Maxi-K channels) are also voltage-sensitive and include KCa1.1 (Slo1), KCa4.1 (Slo2.2), KCa4.2 (Slo2.1) and KCa5.1 (Slo3). These channels do not require calmodulin for activation as they contain three direct bivalent cation binding sites.

External sources of pharmacological information for Calcium-Activated Potassium (KCa) Channels :

Literature for Calcium-Activated Potassium (KCa) Channels

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Ca2+-Activated Potassium Channel Gene Data

Gene Species Gene Symbol Gene Accession No. Protein Accession No.
KCa1.1 Human KCNMA1 NM_002247 Q9UBB0
Mouse Kcnma1 NM_010610 Q08460
Rat Kcnma1 NM_031828 Q9QWW4
KCa2.1 Human KCNN1 NM_002248 Q92952
Mouse Kcnn1 NM_032397 Q9EQR3
Rat Kcnn1 NM_019313 Q3S915
KCa2.2 Human KCNN2 NM_021614 Q9H2S1
Mouse Kcnn2 NM_080465 P58390
Rat Kcnn2 NM_019314 Q3S914
KCa2.3 Human KCNN3 NM_002249 Q9UGI6
Mouse Kcnn3 NM_080466 P58391
Rat Kcnn3 NM_019315 Q3S913
KCa3.1 Human KCNN4 NM_002250 O15554
Mouse Kcnn4 NM_008433 O89109
Rat Kcnn4 NM_023021 Q3S912
KCa4.1 Human KCNT1 NM_020822 Q5JUK3
Mouse Kcnt1 NM_175462 Q6ZPR4
Rat Kcnt1 NM_021853 Q9Z258
KCa4.2 Human KCNT2 NM_198503 Q6UVM3
Mouse Kcnt2 NM_001081027 NP_001074496
Rat Kcnt2 NM_198762 Q6UVM4
KCa5.1 Human KCNU1 NM_001031836 A8MYU2
Mouse Kcnu1 NM_008432 O54982