Potassium intermediate-conductance calcium-activated channel subfamily N member 4 (KCNN4)

Potassium intermediate-conductance calcium-activated channel subfamily N member 4, commonly known as KCa3.1 or the Gardos channel, is a transmembrane protein that mediates the efflux of potassium ions in response to increased intracellular calcium levels. It plays a critical role in regulating cell volume and membrane potential in various cell types, including erythrocytes, lymphocytes, and epithelial cells. In sickle cell anemia, the channel is a key driver of erythrocyte dehydration, leading to the sickling of red blood cells. Beyond hematology, KCa3.1 is involved in the activation and proliferation of T-cells and fibroblasts, making it a therapeutic target for inflammatory and fibrotic diseases. Pharmacological modulation of KCa3.1, primarily through small-molecule inhibitors like Senicapoc, has been explored to treat sickle cell disease and various cancers where the channel is overexpressed. Its unique gating mechanism, which is independent of voltage and strictly dependent on calcium-calmodulin binding, provides a specific pathway for therapeutic intervention.

Other names

Intermediate conductance calcium-activated potassium channel protein 1IKCa1KCa3.1SK4IK1hIK1hSK4Gardos channel

Inhibition of the channel pore to prevent potassium efflux and subsequent cell dehydration or hyperpolarization; or positive allosteric modulation to increase channel open probability.