Kir2.1

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

External links

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