XB-FEAT-1012187

kcnj2

This is the community wiki page for the gene kcnj2 please feel free to add any information that is relevant to this gene that is not already captured elsewhere in Xenbase

nomenclature changes

01/15/2015 Human name has changed for Entrez Gene: 3759. From potassium inwardly-rectifying channel, subfamily J, member 2 to potassium channel, inwardly rectifying subfamily J, member 2

summary from Adams et al 2016. J Physiol 594.12 (2016) pp 3245–3270

Kir2.1 (NP000882.1), encoded in KCNJ2(NM000891.2), is the potassium, inwardly rectifying channel, subfamily J member 2a. It is a 427 amino acid,two-pass, transmembrane protein, with both termini located in the cytoplasm. Kir2.1 homotetramers formaK+channel that contributes to the potassium effluxthat is critical for the repolarization of excitable cell membranes after an action potential, the so-calledIKcurrent. Kir2.1 is negatively regulated (at membrane potentials positive to its equilibrium potential) by binding of spermine, spermidine and Mg2+(Yang et al. 1995), and by phosphorylation of Tyr242. It is positively regulated(at potentials negative to its equilibrium potential) by binding of phosphoinositol bisphosphate (PIP2); threePIP2binding sites have b een identified in the longC terminus of the protein, at amino acids 175–206,207–246 and 324–365 (Soom et al. 2001). Kir2.1 is critical for controlling the membrane voltage of cardiac myocytes;it is the effect of mutations on the QT interval and theU-wave that are thought to cause the cardiac arrhythmia.This symptom is the source of the synonym LQT for longQ-T interval (Hedley et al. 2009). Importantly, however,Kir2.1 also contributes to the resting potential (Vmem)o f undifferentiated embryonic cells, including those found in Xenopus embryos. Its effect on cellular functions goway beyond propagation of action potentials (Jongsma &Wilders, 2001).