KCNA1 / Kv1.1 is a voltage-gated delayed potassium channel that is phylogenetically related to the Drosophila Shaker channel. The encoded protein has six putative transmembrane segments (S1-S6), and the loop between S5 and S6 forms the pore and contains the conserved selectivity filter motif (GYGD). The functional channel is a homotetramer. The N-terminus of the channel is associated with beta subunits that can modify the inactivation properties of the channel as well as affect expression levels. The C-terminus of the channel is complexed to a PDZ domain protein that is responsible for channel targeting. Mutations in this gene have been associated with the rare neurological syndromes myokymia with periodic ataxia (AEMK), as well as autosomal dominant hypomagnesemia. References: Nephron 2018;139:359–366; J. Clin. Invest.119:936–942 (2009)