Voltage-gated potassium channel

Voltage-gated potassium channels (VGKCs) are transmembrane channels specific for potassium and sensitive to voltage changes in the cell's membrane potential. During action potentials, they play a crucial role in returning the depolarized cell to a resting state. Alpha subunits form the actual conductance pore. Based on sequence homology of the hydrophobic transmembrane cores, the alpha subunits of voltage-gated potassium channels are grouped into 12 classes. These are labeled Kvα1-12. The following is a list of the 40 known human voltage-gated potassium channel alpha subunits grouped first according to function and then subgrouped according to the Kv sequence homology classification scheme: slowly inactivating or non-inactivating Kvα1.x - Shaker-related: Kv1.1 (KCNA1), Kv1.2 (KCNA2), Kv1.3 (KCNA3), Kv1.5 (KCNA5), Kv1.6 (KCNA6), Kv1.7 (KCNA7), Kv1.8 (KCNA10) Kvα2.x - Shab-related: Kv2.1 (KCNB1), Kv2.2 (KCNB2) Kvα3.x - Shaw-related: Kv3.1 (KCNC1), Kv3.2 (KCNC2) Kvα7.x: Kv7.1 (KCNQ1) - KvLQT1, Kv7.2 (KCNQ2), Kv7.3 (KCNQ3), Kv7.4 (KCNQ4), Kv7.5 (KCNQ5) Kvα10.x: Kv10.1 (KCNH1) rapidly inactivating Kvα1.x - Shaker-related: Kv1.4 (KCNA4) Kvα4.x - Shal-related: Kv4.1 (KCND1), Kv4.2 (KCND2), Kv4.3 (KCND3) Kvα10.x: Kv10.2 (KCNH5) Passes current more easily in the inward direction (into the cell, from outside). Kvα11.x - ether-a-go-go potassium channels: Kv11.1 (KCNH2) - hERG, Kv11.2 (KCNH6), Kv11.3 (KCNH7) Kvα12.x: Kv12.1 (KCNH8), Kv12.2 (KCNH3), Kv12.3 (KCNH4) Unable to form functional channels as homotetramers but instead heterotetramerize with Kvα2 family members to form conductive channels. Kvα5.x: Kv5.1 (KCNF1) Kvα6.x: Kv6.1 (KCNG1), Kv6.2 (KCNG2), Kv6.3 (KCNG3), Kv6.4 (KCNG4) Kvα8.x: Kv8.1 (KCNV1), Kv8.2 (KCNV2) Kvα9.x: Kv9.1 (KCNS1), Kv9.2 (KCNS2), Kv9.3 (KCNS3) Beta subunits are auxiliary proteins that associate with alpha subunits, sometimes in a α4β4 stoichiometry. These subunits do not conduct current on their own but rather modulate the activity of Kv channels.