Small conductance calcium-activated potassium channel protein 3 (KCa2.3) (KCa2.3)

The Small conductance calcium-activated potassium channel protein 3 (KCa2.3) is a voltage-independent potassium channel that is activated by submicromolar concentrations of intracellular calcium [1, 2]. It functions as a heterotetramer, often associated with calmodulin, which acts as the calcium sensor to trigger channel opening [1]. KCa2.3 is predominantly expressed in the nervous system, vascular endothelium, and the heart, where it regulates membrane potential and cellular excitability [3]. In neurons, it contributes to the afterhyperpolarization phase following an action potential, thereby controlling firing patterns [1, 5].\n\nIn the vasculature, KCa2.3 is a major driver of endothelium-dependent hyperpolarization, which promotes vasodilation and regulates blood pressure [2, 3]. Pathologically, KCa2.3 dysfunction is linked to atrial fibrillation, hypertension, and neuropsychiatric conditions, while its overexpression in certain tumors facilitates cell migration and metastasis [3, 4]. Therapeutic targeting of KCa2.3 involves small molecule modulators like SKA-31 (activator) or apamin (blocker) to manage cardiovascular and neurological disorders [2, 3].

Other names

SK3KCNN3SKCA3hSK3Small conductance calcium-activated potassium channel 3

KCa2.3 channels open in response to increased intracellular calcium levels, allowing potassium ions to flow out of the cell, which results in membrane hyperpolarization and a subsequent reduction in cellular excitability and calcium signaling.