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]
^Doyle DA, Morais Cabral J, Pfuetzner RA, Kuo A, Gulbis JM, Cohen SL, et al. (April 1998). "The structure of the potassium channel: molecular basis of K+ conduction and selectivity". Science. 280 (5360): 69–77. Bibcode:1998Sci...280...69D. doi:10.1126/science.280.5360.69. PMID9525859.
