The protein encoded by KCNJ6 is known as GIRK2, GIRK 2a and KIR 3.2, and is part of a superfamily of inward rectifier channels. GIRK2 is widely distributed in the brain and is an important functional element in dopaminergic, cholinergic, GABAergic and glutamatergic synapses (Saenz del Burgo et al. 2008). Studies have suggested that three different splice variants of GIRK2 (GIRK2a, GIRK2b and GIRK2c) channels may exist in neurons (Isomoto et al. 1997). Of the four GIRK channels (GIRK 1-4) expressed in mammals, GIRK 1-3 are abundantly expressed in the brain (Wickman et al. 2000). Of these, only GIRK2 is capable of forming both heterotetrameric (with GIRK1/3) and homotetrameric functional channels (Liao et al. 1996). By virtue of its channel properties, GIRK2 contributes to the slow inhibitory postsynaptic potentials (IPSCs) as a result of GABAB action (Luscher et al. 1997; Nicoll 2004).
