Biology:Kir2.1

Short description: Protein-coding gene in the species Homo sapiens

Generic protein structure example

The K_ir2.1 inward-rectifier potassium channel is a lipid-gated ion channel 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

In neurogenetics, Kir2.1 is used in Drosophila research to inhibit neurons, as overexpression of this channel will hyperpolarize cells.

In optogenetics, 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.

Expression of Kir2.1 gene in human HEK293 cells induce a transient outward current, creating a steady membrane potential close to the reversal potential of potassium.

Interactions

Kir2.1 has been shown to interact with:

• DLG4,
• Interleukin 16, and
• TRAK2

Further reading

• "International Union of Pharmacology. LIV. Nomenclature and molecular relationships of inwardly rectifying potassium channels.". Pharmacol. Rev. 57 (4): 509–26. 2006. doi:10.1124/pr.57.4.11. PMID 16382105. 
• "Cloning and functional expression of a human gene, hIRK1, encoding the heart inward rectifier K+-channel.". Gene 163 (2): 313–7. 1995. doi:10.1016/0378-1119(95)00244-Z. PMID 7590287. 
• "Primary structure and functional expression of a mouse inward rectifier potassium channel.". Nature 362 (6416): 127–33. 1993. doi:10.1038/362127a0. PMID 7680768. Bibcode: 1993Natur.362..127K. 
• "Molecular cloning and expression of a human heart inward rectifier potassium channel.". NeuroReport 5 (18): 2501–5. 1995. doi:10.1097/00001756-199412000-00024. PMID 7696590. 
• "Inward rectifier K+ channel from human heart and brain: cloning and stable expression in a human cell line.". Am. J. Physiol. 268 (1 Pt 2): H506–11. 1995. doi:10.1152/ajpheart.1995.268.1.H506. PMID 7840300. 
• "Cloning, localization, and functional expression of a human brain inward rectifier potassium channel (hIRK1).". Recept. Channels 3 (3): 175–83. 1996. PMID 8821791. 
• "Inwardly rectifying whole cell potassium current in human blood eosinophils". J. Physiol. 506 (2): 303–18. 1998. doi:10.1111/j.1469-7793.1998.303bw.x. PMID 9490857. 
• "Inwardly rectifying potassium channels in lens epithelium are from the IRK1 (Kir 2.1) family". Exp. Eye Res. 66 (3): 347–59. 1998. doi:10.1006/exer.1997.0432. PMID 9533862. 
• "Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein". J. Neurosci. 19 (18): 7770–80. 1999. doi:10.1523/JNEUROSCI.19-18-07770.1999. PMID 10479680. 
• "Mapping of the physical interaction between the intracellular domains of an inwardly rectifying potassium channel, Kir6.2". J. Biol. Chem. 274 (47): 33393–7. 1999. doi:10.1074/jbc.274.47.33393. PMID 10559219. 
• "Neuronal inwardly rectifying K(+) channels differentially couple to PDZ proteins of the PSD-95/SAP90 family". J. Neurosci. 20 (1): 156–62. 2000. doi:10.1523/JNEUROSCI.20-01-00156.2000. PMID 10627592. 
• "Inward rectifier potassium channel Kir2.2 is associated with synapse-associated protein SAP97". J. Cell Sci. 114 (Pt 5): 987–98. 2001. doi:10.1242/jcs.114.5.987. PMID 11181181. 
• "Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits". FEBS Lett. 491 (3): 305–11. 2001. doi:10.1016/S0014-5793(01)02202-5. PMID 11240146. 
• "A sequence motif responsible for ER export and surface expression of Kir2.0 inward rectifier K(+) channels". FEBS Lett. 493 (2–3): 129–33. 2001. doi:10.1016/S0014-5793(01)02286-4. PMID 11287009. 
• "Targeting of an A kinase-anchoring protein, AKAP79, to an inwardly rectifying potassium channel, Kir2.1". J. Biol. Chem. 276 (23): 20499–505. 2001. doi:10.1074/jbc.M101425200. PMID 11287423. 
• "Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome". Cell 105 (4): 511–9. 2001. doi:10.1016/S0092-8674(01)00342-7. PMID 11371347. 
• "Characterization of inwardly rectifying K(+) conductance across the basolateral membrane of rat tracheal epithelia". Biochem. Biophys. Res. Commun. 288 (4): 914–20. 2001. doi:10.1006/bbrc.2001.5831. PMID 11688996. 
• "Modulation of the inward rectifier potassium channel IRK1 by the Ras signaling pathway". J. Biol. Chem. 277 (14): 12158–63. 2002. doi:10.1074/jbc.M110466200. PMID 11809752. 
• "Heteromerization of Kir2.x potassium channels contributes to the phenotype of Andersen's syndrome". Proc. Natl. Acad. Sci. U.S.A. 99 (11): 7774–9. 2002. doi:10.1073/pnas.102609499. PMID 12032359. Bibcode: 2002PNAS...99.7774P. 
• "Novel KCNJ2 mutation in familial periodic paralysis with ventricular dysrhythmia". Circulation 105 (22): 2592–4. 2002. doi:10.1161/01.CIR.0000019906.35135.A3. PMID 12045162. 

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)