BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 1 (KCNS1)
KCNS1, also called delayed-rectifier K(+) channel alpha subunit 1 or voltage-gated potassium channel subunit Kv9.1, is a modulatory alpha subunit of voltage-gated potassium channel that mediates neuropathic pain following nerve injury. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS1 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.
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