The two-pore-domain or tandem pore domain potassium channels are a family of 15 members that form what is known as leak channels which possess Goldman-Hodgkin-Katz (open) rectification.^[1] These channels are regulated by several mechanisms including signaling lipids, oxygen tension, pH, mechanical stretch, and G-proteins.^[2] Two-pore-domain potassium channels correspond structurally to a inward-rectifier potassium channel α-subunits. Each inward-rectifier potassium channel α-subunit is composed of two transmembrane α-helices, a pore helix and a potassium ion selectivity filter sequence and assembles into a tetramer forming the complete channel.^[3] The two-pore domain potassium channels instead are dimers where each subunit is essentially two α-subunits joined together.^[4]

Each single channel does not have two pores; the name of the channel comes from the fact that each subunit has two P (pore) domains in its primary sequence.^[5] To quote Rang and Dale (2015), "The nomenclature is misleading, especially when they are incorrectly referred to as two-pore channels".^[6]

Below is a list of the 15 known two-pore-domain human potassium channels:^[1]

K2P1 Human K2P1 PDB: 3UKM​ Identifiers Symbol K2P1 HGNC 6272 RefSeq NP_002236.1 UniProt O00180 Search for Structures Swiss-model Domains InterPro

K2P2 Human K2P2 PDB: 4TWK​ Identifiers Symbol K2P2 HGNC 6277 RefSeq NP_055032.1 UniProt O95069 Search for Structures Swiss-model Domains InterPro

K2P3 Human K2P3 PDB: 6RV3​ Identifiers Symbol K2P3 HGNC 6278 RefSeq NP_002237.1 UniProt O14649 Search for Structures Swiss-model Domains InterPro