View source for Kir2.1

{{DISPLAYTITLE:K<sub>ir</sub>2.1}}
{{Infobox_gene}}
The '''K<sub>ir</sub>2.1''' [[inward-rectifier potassium ion channel]] is encoded by the {{gene|KCNJ2}} gene.<ref name="pmid7696590">{{cite journal |vauthors=Raab-Graham KF, Radeke CM, Vandenberg CA | title = Molecular cloning and expression of a human heart inward rectifier potassium channel | journal = NeuroReport | volume = 5 | issue = 18 | pages = 2501–5 | year = 1994 | pmid = 7696590 | doi = 10.1097/00001756-199412000-00024 }}</ref><ref name="pmid11240146">{{cite journal |vauthors=Derst C, Karschin C, Wischmeyer E, Hirsch JR, Preisig-Müller R, Rajan S, Engel H, Grzeschik K, Daut J, Karschin A | title = Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits | journal = FEBS Lett. | volume = 491 | issue = 3 | pages = 305–11 | year = 2001 | pmid = 11240146 | doi = 10.1016/S0014-5793(01)02202-5 }}</ref><ref name="pmid16382105">{{cite journal |vauthors=Kubo Y, Adelman JP, Clapham DE, Jan LY, Karschin A, Kurachi Y, Lazdunski M, Nichols CG, Seino S, Vandenberg CA | title = International Union of Pharmacology. LIV. Nomenclature and molecular relationships of inwardly rectifying potassium channels | journal = Pharmacol. Rev. | volume = 57 | issue = 4 | pages = 509–26 | year = 2005 | pmid = 16382105 | doi = 10.1124/pr.57.4.11 }}</ref>

== Clinical significance ==

A defect in this gene is associated with [[Andersen-Tawil syndrome]].<ref name="pmid15176430">{{cite journal |vauthors=Donaldson MR, Yoon G, Fu YH, Ptacek LJ | title = Andersen-Tawil syndrome: a model of clinical variability, pleiotropy, and genetic heterogeneity | journal = Ann. Med. | volume = 36 Suppl 1 | issue = | pages = 92–7 | year = 2004 | pmid = 15176430 | doi = 10.1080/17431380410032490 }}</ref>

A mutation in the KCNJ2 gene  has also been shown to cause [[short QT syndrome]].<ref name="pmid15761194">{{cite journal |vauthors=Priori SG, Pandit SV, Rivolta I, Berenfeld O, Ronchetti E, Dhamoon A, Napolitano C, Anumonwo J, di Barletta MR, Gudapakkam S, Bosi G, Stramba-Badiale M, Jalife J | title = A novel form of short QT syndrome (SQT3) is caused by a mutation in the KCNJ2 gene | journal = Circ. Res. | volume = 96 | issue = 7 | pages = 800–7 |date=April 2005 | pmid = 15761194 | doi = 10.1161/01.RES.0000162101.76263.8c }}</ref>

== 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 [[optogenetics|optogenetic research]] to inhibit neurons with light.<ref name="pmid20303157">{{cite journal |vauthors=Gradinaru V, Zhang F, Ramakrishnan C, Mattis J, Prakash R, Diester I, Goshen I, Thompson KR, Deisseroth K | title = Molecular and cellular approaches for diversifying and extending optogenetics | journal = Cell | volume = 141 | issue = 1 | pages = 154–65 |date=April 2010 | pmid = 20303157 | doi = 10.1016/j.cell.2010.02.037 }}</ref>

Expression of Kir2.1 gene in human [[HEK 293 cells|HEK293 cells]] induce a transient outward current, creating a steady [[membrane potential]] of around -70 mV.<ref>{{Cite journal|last=Zhang|first=De-Yong|last2=Lau|first2=Chu-Pak|last3=Li|first3=Gui-Rong|date=2009-04-01|title=Human Kir2.1 channel carries a transient outward potassium current with inward rectification|url=https://www.ncbi.nlm.nih.gov/pubmed/19002489|journal=Pflugers Archiv: European Journal of Physiology|volume=457|issue=6|pages=1275–1285|doi=10.1007/s00424-008-0608-0|issn=1432-2013|pmid=19002489}}</ref>

== Interactions ==

Kir2.1 has been shown to [[Protein-protein interaction|interact]] with:
* [[DLG4]],<ref name = pmid10627592>{{cite journal |vauthors=Nehring RB, Wischmeyer E, Döring F, Veh RW, Sheng M, Karschin A | title = Neuronal inwardly rectifying K(+) channels differentially couple to PDZ proteins of the PSD-95/SAP90 family | journal = J. Neurosci. | volume = 20 | issue = 1 | pages = 156–62 | year = 2000 | pmid = 10627592 | doi = }}</ref> 
* [[Interleukin 16]],<ref name = pmid10479680>{{cite journal |vauthors=Kurschner C, Yuzaki M | title = Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein | journal = J. Neurosci. | volume = 19 | issue = 18 | pages = 7770–80 | year = 1999 | pmid = 10479680 | doi = }}</ref> and
* [[TRAK2]] <ref name = pmid16895905>{{cite journal |vauthors=Grishin A, Li H, Levitan ES, Zaks-Makhina E | title = Identification of gamma-aminobutyric acid receptor-interacting factor 1 (TRAK2) as a trafficking factor for the K+ channel Kir2.1 | journal = J. Biol. Chem. | volume = 281 | issue = 40 | pages = 30104–11 | year = 2006 | pmid = 16895905 | doi = 10.1074/jbc.M602439200 }}</ref>

== References ==
{{reflist|30em}}

== Further reading ==
{{refbegin | 2}}
* {{cite journal   |vauthors=Kubo Y, Adelman JP, Clapham DE, etal |title=International Union of Pharmacology. LIV. Nomenclature and molecular relationships of inwardly rectifying potassium channels. |journal=Pharmacol. Rev. |volume=57 |issue= 4 |pages= 509–26 |year= 2006 |pmid= 16382105 |doi= 10.1124/pr.57.4.11 }}
* {{cite journal  |vauthors=Wood LS, Tsai TD, Lee KS, Vogeli G |title=Cloning and functional expression of a human gene, hIRK1, encoding the heart inward rectifier K+-channel. |journal=Gene |volume=163 |issue= 2 |pages= 313–7 |year= 1995 |pmid= 7590287 |doi=10.1016/0378-1119(95)00244-Z  }}
* {{cite journal  |vauthors=Kubo Y, Baldwin TJ, Jan YN, Jan LY |title=Primary structure and functional expression of a mouse inward rectifier potassium channel. |journal=Nature |volume=362 |issue= 6416 |pages= 127–33 |year= 1993 |pmid= 7680768 |doi= 10.1038/362127a0 }}
* {{cite journal  |vauthors=Raab-Graham KF, Radeke CM, Vandenberg CA |title=Molecular cloning and expression of a human heart inward rectifier potassium channel. |journal=NeuroReport |volume=5 |issue= 18 |pages= 2501–5 |year= 1995 |pmid= 7696590 |doi=10.1097/00001756-199412000-00024  }}
* {{cite journal   |vauthors=Ashen MD, O'Rourke B, Kluge KA, etal |title=Inward rectifier K+ channel from human heart and brain: cloning and stable expression in a human cell line. |journal=Am. J. Physiol. |volume=268 |issue= 1 Pt 2 |pages= H506–11 |year= 1995 |pmid= 7840300 |doi=  }}
* {{cite journal  |vauthors=Tang W, Qin CL, Yang XC |title=Cloning, localization, and functional expression of a human brain inward rectifier potassium channel (hIRK1). |journal=Recept. Channels |volume=3 |issue= 3 |pages= 175–83 |year= 1996 |pmid= 8821791 |doi=  }}
* {{cite journal   |vauthors=Tare M, Prestwich SA, Gordienko DV, etal |title=Inwardly rectifying whole cell potassium current in human blood eosinophils |journal=J. Physiol. |volume=506 |issue=  2|pages= 303–18 |year= 1998 |pmid= 9490857 |doi=10.1111/j.1469-7793.1998.303bw.x  | pmc=2230727  }}
* {{cite journal  |vauthors=Rae JL, Shepard AR |title=Inwardly rectifying potassium channels in lens epithelium are from the IRK1 (Kir 2.1) family |journal=Exp. Eye Res. |volume=66 |issue= 3 |pages= 347–59 |year= 1998 |pmid= 9533862 |doi= 10.1006/exer.1997.0432 }}
* {{cite journal  |vauthors=Kurschner C, Yuzaki M |title=Neuronal interleukin-16 (NIL-16): a dual function PDZ domain protein |journal=J. Neurosci. |volume=19 |issue= 18 |pages= 7770–80 |year= 1999 |pmid= 10479680 |doi=  }}
* {{cite journal  |vauthors=Tucker SJ, Ashcroft FM |title=Mapping of the physical interaction between the intracellular domains of an inwardly rectifying potassium channel, Kir6.2 |journal=J. Biol. Chem. |volume=274 |issue= 47 |pages= 33393–7 |year= 1999 |pmid= 10559219 |doi=10.1074/jbc.274.47.33393  }}
* {{cite journal   |vauthors=Nehring RB, Wischmeyer E, Döring F, etal |title=Neuronal inwardly rectifying K(+) channels differentially couple to PDZ proteins of the PSD-95/SAP90 family |journal=J. Neurosci. |volume=20 |issue= 1 |pages= 156–62 |year= 2000 |pmid= 10627592 |doi=  }}
* {{cite journal   |vauthors=Leonoudakis D, Mailliard W, Wingerd K, etal |title=Inward rectifier potassium channel Kir2.2 is associated with synapse-associated protein SAP97 |journal=J. Cell Sci. |volume=114 |issue= Pt 5 |pages= 987–98 |year= 2001 |pmid= 11181181 |doi=  }}
* {{cite journal   |vauthors=Derst C, Karschin C, Wischmeyer E, etal |title=Genetic and functional linkage of Kir5.1 and Kir2.1 channel subunits |journal=FEBS Lett. |volume=491 |issue= 3 |pages= 305–11 |year= 2001 |pmid= 11240146 |doi=10.1016/S0014-5793(01)02202-5  }}
* {{cite journal  |vauthors=Stockklausner C, Ludwig J, Ruppersberg JP, Klöcker N |title=A sequence motif responsible for ER export and surface expression of Kir2.0 inward rectifier K(+) channels |journal=FEBS Lett. |volume=493 |issue= 2–3 |pages= 129–33 |year= 2001 |pmid= 11287009 |doi=10.1016/S0014-5793(01)02286-4  }}
* {{cite journal  |vauthors=Dart C, Leyland ML |title=Targeting of an A kinase-anchoring protein, AKAP79, to an inwardly rectifying potassium channel, Kir2.1 |journal=J. Biol. Chem. |volume=276 |issue= 23 |pages= 20499–505 |year= 2001 |pmid= 11287423 |doi= 10.1074/jbc.M101425200 }}
* {{cite journal   |vauthors=Plaster NM, Tawil R, Tristani-Firouzi M, etal |title=Mutations in Kir2.1 cause the developmental and episodic electrical phenotypes of Andersen's syndrome |journal=Cell |volume=105 |issue= 4 |pages= 511–9 |year= 2001 |pmid= 11371347 |doi=10.1016/S0092-8674(01)00342-7  }}
* {{cite journal   |vauthors=Jeong JS, Lee HJ, Jung JS, etal |title=Characterization of inwardly rectifying K(+) conductance across the basolateral membrane of rat tracheal epithelia |journal=Biochem. Biophys. Res. Commun. |volume=288 |issue= 4 |pages= 914–20 |year= 2001 |pmid= 11688996 |doi= 10.1006/bbrc.2001.5831 }}
* {{cite journal   |vauthors=Giovannardi S, Forlani G, Balestrini M, etal |title=Modulation of the inward rectifier potassium channel IRK1 by the Ras signaling pathway |journal=J. Biol. Chem. |volume=277 |issue= 14 |pages= 12158–63 |year= 2002 |pmid= 11809752 |doi= 10.1074/jbc.M110466200 }}
* {{cite journal   |vauthors=Preisig-Müller R, Schlichthörl G, Goerge T, etal |title=Heteromerization of Kir2.x potassium channels contributes to the phenotype of Andersen's syndrome |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=99 |issue= 11 |pages= 7774–9 |year= 2002 |pmid= 12032359 |doi= 10.1073/pnas.102609499  | pmc=124349 }}
* {{cite journal   |vauthors=Ai T, Fujiwara Y, Tsuji K, etal |title=Novel KCNJ2 mutation in familial periodic paralysis with ventricular dysrhythmia |journal=Circulation |volume=105 |issue= 22 |pages= 2592–4 |year= 2002 |pmid= 12045162 |doi=10.1161/01.CIR.0000019906.35135.A3  }}
{{refend}}

== External links ==
* [https://www.ncbi.nlm.nih.gov/books/NBK1264/  GeneReviews/NCBI/NIH/UW entry on Andersen-Tawil syndrome]
* [https://www.ncbi.nlm.nih.gov/omim/170390,600681,170390,600681  OMIM entries on Anderson-Tawil syndrome]
* {{MeshName|KCNJ2+protein,+human}}
* {{MeshName|Kir2.1+channel}}

{{PDB Gallery|geneid=3759}}
{{Ion channels|g3}}

[[Category:Ion channels]]


{{membrane-protein-stub}}