Potassium inwardly rectifying channel subfamily J member 10 (KCNJ10) (Kir4.1)

The Flicker potassium channel, molecularly identified as the Potassium inwardly rectifying channel subfamily J member 10 (KCNJ10 or Kir4.1), is a crucial ion channel primarily located in the basolateral membrane of the renal thick ascending limb and distal convoluted tubule, as well as in glial cells of the central nervous system (UniProt P78508; PubMed 25634686). In the kidney, it often functions as a heteromer with Kir5.1, providing the necessary potassium conductance for the Na+/K+-ATPase to maintain the electrochemical gradient required for sodium and magnesium reabsorption (PubMed 10449505). In the brain, Kir4.1 is responsible for potassium spatial buffering, a process where astrocytes remove excess extracellular potassium generated during neuronal activity to prevent over-excitability (PubMed 15165731). Mutations in the gene encoding this channel lead to EAST (Epilepsy, Ataxia, Sensorineural deafness, and Tubulopathy) syndrome, highlighting its multi-organ importance (NEJM 360:1960-70). Pharmacologically, the channel is sensitive to various compounds including barium, quinine, and certain antidepressants like fluoxetine, which inhibit its activity and are used as tools to study its role in epilepsy and hypertension (PubMed 17606554).

Other names

Flicker potassium channelFlicker-type K+ channelKCNJ10Inward rectifier K+ channel Kir4.1BIRK10ATP-sensitive inward rectifier potassium channel 10

Inhibition of Kir4.1 reduces basolateral potassium conductance in the kidney, impairing sodium reabsorption and magnesium transport. In the CNS, inhibition or loss of function disrupts glial potassium spatial buffering, leading to increased neuronal excitability.