BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNA/Kv1 subfamily of Shaker-type voltage-dependent potassium channels
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. The potassium voltage-gated channel subfamily Kv1, also known as subfamily A, contains eight alpha subunit members, Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.4 (KCNA4), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 (KCNA7), and Kv1.8 (KCNA10), which are orthologs of the Shaker gene in Drosophila. They are delayed rectifiers except for Kv1.4 (KCNA4), which is an A-type potassium channel. Delayed rectifiers are slow opening and closing voltage-gated potassium channels. Because of their delayed activation kinetics, they play an important role in controlling action potential duration. A-type channels are fast/rapidly inactivating potassium channels. Kv1/KCNA subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other Kv1/KCNA alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.
Jiyao W et al.(2023). "The conserved domain database in 2023.",