Lipid-gated ion channels

Lipid-gated ion-channel Kir2.2
Tetrameric Kir2.2 (grey trace) bound to four PIP2 molecules (carbon:yellow; oxygen:red). Potassium ions (purple) are shown in the open conduction pathway. Grey rectangles indicate the membrane border.
Identifiers
Symbol	Kir2.2
OPM protein	3SPG

Lipid-gated ion channels are a class of ion channels whose conductance of ions through the membrane depends directly on lipids. Classically the lipids are membrane resident anionic signaling lipids that bind to the transmembrane domain on the inner leaflet of the plasma membrane with properties of a classic ligand. Other classes of lipid-gated channels include the mechanosensitive ion channels that respond to lipid tension, thickness, and hydrophobic mismatch. A lipid ligand differs from a lipid cofactor in that a ligand derives its function by dissociating from the channel while a cofactor typically derives its function by remaining bound.^[1]