The K
ir2.1
inward-rectifier potassium channel
Inward-rectifier potassium channels (Kir, IRK) are a specific Lipid-gated_ion_channels, lipid-gated subset of potassium channels. To date, seven subfamilies have been identified in various mammalian cell types, plants, and bacteria. They are acti ...
is a
lipid-gated ion channel
Lipid-gated ion channels are a class of ion channels whose conductance of ions through the membrane depends directly on lipids. Classically the lipids are membrane resident anionic signaling lipids that bind to the transmembrane domain on the inn ...
encoded by the 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
Short QT syndrome (SQT) is a very rare genetics, genetic disease of the electrical system of the heart, and is associated with an increased risk of Heart arrhythmia, abnormal heart rhythms and sudden cardiac death. The syndrome gets its name from ...
.
In research
In neurogenetics, Kir2.1 is used in ''
Drosophila
''Drosophila'' (), from Ancient Greek δρόσος (''drósos''), meaning "dew", and φίλος (''phílos''), meaning "loving", is a genus of fly, belonging to the family Drosophilidae, whose members are often called "small fruit flies" or p ...
'' 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
Halorhodopsin is a seven-transmembrane retinylidene protein from microbial rhodopsin family. It is a chloride-specific light-activated ion pump found in archaea known as halobacteria. It is activated by green light wavelengths of approximatel ...
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
Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. It equals the interior potential minus the exterior potential. This is th ...
close to the
reversal potential of potassium.
Interactions
Kir2.1 has been shown to
interact
Advocates for Informed Choice, dba interACT or interACT Advocates for Intersex Youth, is a 501(c)(3) nonprofit organization advocating for the legal and human rights of children with intersex traits. The organization was founded in 2006 and fo ...
with:
*
DLG4
PSD-95 (postsynaptic density protein 95) also known as SAP-90 (synapse-associated protein 90) is a protein that in humans is encoded by the ''DLG4'' (discs large homolog 4) gene.
PSD-95 is a member of the membrane-associated guanylate kinase (MA ...
,
*
Interleukin 16,
and
*
TRAK2
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Andersen-Tawil syndrome OMIM entries on Anderson-Tawil syndrome*
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Ion channels
Long stubs with short prose
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