Two-pore-domain potassium channel

"TASK" redirects here. For other uses, see Task.

Not to be confused with the small family of two-pore channels.

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]

A decrease in these leak channels activity is known as 'channel arrest', which reduces oxygen consumption^[7] and allows animals to survive anoxia.^[8]

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

Gene	Channel[9]	Family	Aliases
KCNK1	K2p1.1	TWIK[2][10]	TWIK-1
KCNK2	K2p2.1	TREK[2][10]	TREK-1
KCNK3	K2p3.1	TASK[2][10]	TASK-1
KCNK4	K2p4.1	TREK[2][10]	TRAAK[11]
KCNK5	K2p5.1	TASK[2][10]	TASK-2[12]
KCNK6	K2p6.1	TWIK[2][10]	TWIK-2
KCNK7	K2p7.1	TWIK[2][10]
KCNK9	K2p9.1	TASK[2][10]	TASK-3
KCNK10	K2p10.1	TREK[2][10]	TREK-2
KCNK12	K2p12.1	THIK	THIK-2
KCNK13	K2p13.1	THIK	THIK-1
KCNK15	K2p15.1	TASK[2][10]	TASK-5
KCNK16	K2p16.1	TALK[2][10]	TALK-1
KCNK17	K2p17.1	TALK[2][10]	TALK-2, TASK-4
KCNK18	K2p18.1		TRIK, TRESK[2][10][13][14]

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

See also

• Ion channel
• Potassium channel