The renal outer medullary potassium channel (ROMK) is an ATP-dependent potassium channel (Kir1.1) that transports potassium out of cells. It plays an important role in potassium recycling in the thick ascending limb (TAL) and potassium secretion in the cortical collecting duct (CCD) of the nephron. In humans, ROMK is encoded by the KCNJ1 gene. Multiple transcript variants encoding different isoforms have been found for this gene.
Inward-rectifier potassium channels (Kir, IRK) are a specific lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are activated by phosphatidylinositol 4,5-bisphosphate (PIP2). The malfunction of the channels has been implicated in several diseases. IRK channels possess a pore domain, homologous to that of voltage-gated ion channels, and flanking transmembrane segments (TMSs). They may exist in the membrane as homo- or heterooligomers and each monomer possesses between 2 and 4 TMSs. In terms of function, these proteins transport potassium (K+), with a greater tendency for K+ uptake than K+ export. The process of inward-rectification was discovered by Denis Noble in cardiac muscle cells in 1960s and by Richard Adrian and Alan Hodgkin in 1970 in skeletal muscle cells.
The Kir2.1 inward-rectifier potassium channel is a lipid-gated ion channel encoded by the KCNJ2 gene.
Kir6.2 is a major subunit of the ATP-sensitive K+ channel, a lipid-gated inward-rectifier potassium ion channel. The gene encoding the channel is called KCNJ11 and mutations in this gene are associated with congenital hyperinsulinism.
G protein-activated inward rectifier potassium channel 2 is a protein that in humans is encoded by the KCNJ6 gene. Mutation in KCNJ6 gene has been proposed to be the cause of Keppen-Lubinsky Syndrome (KPLBS).
Potassium inwardly-rectifying channel, subfamily J, member 4, also known as KCNJ4 or Kir2.3, is a human gene.
Potassium inwardly-rectifying channel, subfamily J, member 8, also known as KCNJ8, is a human gene encoding the Kir6.1 protein. A mutation in KCNJ8 has been associated with cardiac arrest in the early repolarization syndrome.
G protein-activated inward rectifier potassium channel 4(GIRK-4) is a protein that in humans is encoded by the KCNJ5 gene and is a type of G protein-gated ion channel.
ATP-sensitive inward rectifier potassium channel 12 is a lipid-gated ion channel that in humans is encoded by the KCNJ12 gene.
G protein-activated inward rectifier potassium channel 1(GIRK-1) is encoded in the human by the gene KCNJ3.
ATP-sensitive inward rectifier potassium channel 10 is a protein that in humans is encoded by the KCNJ10 gene.
Potassium inwardly-rectifying channel, subfamily J, member 15, also known as KCNJ15 is a human gene, which encodes the Kir4.2 protein.
Potassium channel subfamily K member 1 is a protein that in humans is encoded by the KCNK1 gene.
Lin-7 homolog A is a protein that in humans is encoded by the LIN7A gene.
Lin-7 homolog B is a protein that in humans is encoded by the LIN7B gene.
Potassium channel subfamily K member 6 is a protein that in humans is encoded by the KCNK6 gene.
Potassium inwardly-rectifying channel, subfamily J, member 16 (KCNJ16) is a human gene encoding the Kir5.1 protein.
G protein-activated inward rectifier potassium channel 3 is a protein that in humans is encoded by the KCNJ9 gene.
Potassium inwardly-rectifying channel, subfamily J, member 13 (KCNJ13) is a human gene encoding the Kir7.1 protein.
The Kir2.6 also known as inward rectifier potassium channel 18 is a protein that in humans is encoded by the KCNJ18 gene. Kir2.6 is an inward-rectifier potassium ion channel.
