Ion channel that contributes to passive transmembrane potassium transport (PubMed:23169818). 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 and isoform 2 and reduces cell surface expression of isoform 2. Homodimer; disulfide-linked (Ref.13). Heterodimer with KCNK1; disulfide-linked (By similarity). Interacts with BVES; the interaction enhances KCNK2 surface expression and is inhibited by cAMP (PubMed:26642364). Isoform 4 is detected in kidney, adrenal gland and brain where it is preferentially expressed in the amygdala but not found in thalamus, hypothalamus, hippocampus or substantia nigra. The C-terminal region of isoform 4 mediates its intracellular retention. Phosphorylation at Ser-348 controls the reversible conversion from a leak channel to a voltage-dependent channel. Activated by volatile general anesthetics such as chloroform, halothane and isoflurane. Belongs to the two pore domain potassium channel (TC 1.A.1.8) family.