Inward rectifier potassium channel 2.6 (Kir2.6) (Kir2.6)

Inward rectifier potassium channel 2.6 (Kir2.6), encoded by the KCNJ18 gene, is a member of the Kir2 family of potassium channels primarily expressed in skeletal muscle (UniProt P0DPI2; NCBI Gene 100134444). It plays a critical role in maintaining the resting membrane potential and regulating muscle excitability by allowing potassium ions to flow into the cell more readily than out (Ryan et al., 2010, Cell). Mutations in KCNJ18 are a major genetic cause of thyrotoxic periodic paralysis (TPP), a condition characterized by episodes of muscle weakness and hypokalemia triggered by high thyroid hormone levels (StatPearls, Thyrotoxic Periodic Paralysis). The channel's expression and activity are transcriptionally regulated by thyroid hormones and acutely modulated by insulin, which can lead to an intracellular shift of potassium (PubMed 20056887). While there are currently no FDA-approved drugs that specifically target Kir2.6, it remains a significant focus for understanding the pathophysiology of periodic paralyses. Management of Kir2.6-related disorders typically involves addressing the underlying hyperthyroidism and using non-specific treatments like beta-blockers or potassium supplementation. Experimental blockers like barium and cesium are used in research to study the channel's pore properties and its contribution to membrane conductance. Understanding Kir2.6 is essential for developing targeted therapies that could stabilize muscle membranes without affecting other vital potassium channels in the heart or brain.

Other names

KCNJ18Potassium inwardly-rectifying channel subfamily J member 18Inwardly rectifying potassium channel 18Kir2.6

Modulation of inward potassium rectification to stabilize the resting membrane potential of skeletal muscle cells, preventing hyperpolarization-induced muscle paralysis.