TRAAK | Potassium Channel Subfamily K Member 4
Tandem-Pore Domain Potassium Channels
Tandem pore domain K+ channels have been classified into six subfamilies; tandem pore domains in weak rectifying K+ channel (TWIK), TWIK-related K+ channel (TREK), TWIK-related acid-sensitive K+ channel (TASK), TWIK-related alkaline pH-activated K+ channel (TALK), tandem pore domain halothane-inhibted K+ channel (THIK), TWIK-releated spinal cord K+ channel (TRESK)
15 members: K2P1.1 (TWIK-1); K2P2.1 (TREK-1); K2P3.1 (TASK-1); K2P4.1 (TRAAK); K2P5.1 (TASK-2); K2P6.1 (TWIK-2); K2P7.1; K2P9.1 (TASK-3); K2P10.1 (TREK-2); K2P12.1 (THIK-2); K2P13.1 (THIK-1); K2P15.1 (TASK-5); K2P16.1 (TALK-1); K2P17.1 (TASK-2, TASK-4); K2P18.1 (TRIK, TRESK);
The channel protein contains four transmembrane domains, which form two pore loops between domains 1–2 and 3–4. Two subunits associate to form a dimer with bilateral symmetry around the pore. Homodimers and heterodimers are possible.
Several mechanisms including oxygen tension, pH, mechanical stretch, and G-proteins