Two-pore-domain potassium channel
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 rectification. These channels are regulated by several mechanisms including signaling lipids, oxygen tension, pH, mechanical stretch, and G-proteins. Their name is derived from the fact that the α subunits consist of four transmembrane segments, each containing two pore loops. As such, they structurally correspond to two inward-rectifier α subunits and thus form dimers in the membrane.
Each single channel does not have two pores; the name of the channel comes from the fact that each subunit has two P domains in its primary sequence. To quote Rang and Dale, "The nomenclature is
misleading, especially when they are incorrectly referred to as two-pore channels".
Below is a list of the 15 known two-pore-domain human potassium channels:
