Kir2.1

Potassium channel, inwardly rectifying subfamily J, member 2
250px PDB rendering based on 1u4f.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 1u4f, 2gix
Identifiers
Symbols	KCNJ2 ; ATFB9; HHBIRK1; HHIRK1; IRK1; KIR2.1; LQT7; SQT3
External IDs	OMIM: 600681 MGI: 104744 HomoloGene: 20249 IUPHAR: 430 GeneCards: KCNJ2 Gene
Gene ontology Molecular function • inward rectifier potassium channel activity • phosphatidylinositol-4,5-bisphosphate binding • identical protein binding • voltage-gated potassium channel activity involved in cardiac muscle cell action potential repolarization Cellular component • smooth endoplasmic reticulum • rough endoplasmic reticulum • Golgi apparatus • plasma membrane • integral component of plasma membrane • voltage-gated potassium channel complex • intercalated disc • T-tubule • intrinsic component of membrane • neuronal cell body • dendritic spine Biological process • potassium ion transport • synaptic transmission • potassium ion import • regulation of skeletal muscle contraction via regulation of action potential • magnesium ion transport • cellular potassium ion homeostasis • protein homotetramerization • relaxation of cardiac muscle • regulation of resting membrane potential • regulation of membrane repolarization • cellular response to mechanical stimulus • potassium ion transmembrane transport • cardiac muscle cell action potential involved in contraction • membrane repolarization during action potential • membrane depolarization during cardiac muscle cell action potential • membrane repolarization during cardiac muscle cell action potential • regulation of heart rate by cardiac conduction • relaxation of skeletal muscle • positive regulation of potassium ion transmembrane transport Sources: Amigo / QuickGO
RNA expression pattern
File:PBB GE KCNJ2 206765 at tn.png
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	3759	16518
Ensembl	ENSG00000123700	ENSMUSG00000041695
UniProt	P63252	P35561
RefSeq (mRNA)	NM_000891	NM_008425
RefSeq (protein)	NP_000882	NP_032451
Location (UCSC)	Chr 17: 70.17 – 70.18 Mb	Chr 11: 111.07 – 111.08 Mb
PubMed search	[1]	[2]

The K_ir2.1 inward-rectifier potassium ion channel is encoded by the KCNJ2 gene.

Clinical significance

A defect in this gene is associated with Andersen-Tawil syndrome.

A mutation in the KCNJ2 gene has also been shown to cause short QT syndrome.

In research

A trafficking sequence from Kir2.1 has been added to halorhodopsin to improve its membrane localization. The resulting protein eNpHR3.0 is used in optogenetic research to inhibit neurons with light.

Interactions

Kir2.1 has been shown to interact with:

• DLG4,
• Interleukin 16, and
• TRAK2

External links

• GeneReviews/NCBI/NIH/UW entry on Andersen-Tawil syndrome
• OMIM entries on Anderson-Tawil syndrome
• KCNJ2 protein, human at the US National Library of Medicine Medical Subject Headings (MeSH)
• Kir2.1 channel at the US National Library of Medicine Medical Subject Headings (MeSH)