Ion channel that contributes to passive transmembrane potassium transport. Reversibly converts between a voltage-insensitive potassium leak channel and a voltage-dependent outward rectifying potassium channel in a phosphorylation-dependent manner (PubMed:11319556). In astrocytes, forms mostly heterodimeric potassium channels with KCNK1, with only a minor proportion of functional channels containing homodimeric KCNK2. In astrocytes, the heterodimer formed by KCNK1 and KCNK2 is required for rapid glutamate release in response to activation of G-protein coupled receptors, such as F2R and CNR1 (By similarity). Does not display channel activity but reduces the channel activity of isoform 1, isoform 2 and isoform 4 and reduces cell surface expression of isoform 2. Homodimer; disulfide-linked (By similarity). Heterodimer with KCNK1; disulfide-linked (By similarity). Interacts with BVES; the interaction enhances KCNK2 surface expression and is inhibited by cAMP (By similarity). Expressed in cardiomyocytes (at protein level). Expressed in various brain regions including the lateral olfactory tract, piriform cortex of the forebrain, paraventricular and anteromedial thalamic nuclei, brainstem, caudate putamen, nucleus accumbens, neocortex and interpeduncular nucleus. Isoform 5 is expressed in brain and kidney. The C-terminal region of isoform 5 mediates its intracellular retention. Phosphorylation at Ser-348 controls the reversible conversion from a leak channel to a voltage-dependent channel. Activated by arachadonic acid, mechanical stretching and intracellular acidification. Belongs to the two pore domain potassium channel (TC 1.A.1.8) family.