K_ir4.1 is a member of the inward rectifying K⁺ channel family. The family includes 15 members that are structurally and functionally different from the voltage-dependent K⁺ channels.

The family’s topology consists of two transmembrane domains that flank a single and highly conserved pore region with intracellular N- and C-termini. As is the case for the voltage-dependent K⁺ channels the functional unit for the K_ir channels is composed of four subunit that can assembly as either homo or heteromers.

K_ir channels are characterized by a K⁺ efflux that is limited by depolarizing membrane potentials thus making them essential for controlling resting membrane potential and K⁺ homeostasis.

K_ir4.1 is a member of the K_ir4 subfamily that includes one other member: K_ir4.2. K_ir4.1 can co-assemble with K_ir4.2 but also with other K_ir channels such as K_ir2.1 and K_ir5.1.

The K_ir4 subfamily has been classified as weak rectifiers with intermediate conductance. 

K_ir4.1, encoded by KCNJ10, is mainly expressed in brain, specifically in glia cells, but also in retina, ear and kidney.^1,2

It has been proposed that K_ir4.1 has an essential role in glial K⁺ buffering, a process that re-uptakes the K⁺ released during neuronal activity into the intracellular interstitial space. Loss of K_ir4.1 causes retinal defects and loss of endochoclear potential.³