Anti-GIRK2 (Kir3.2) Antibody

K_ir3.2 (or G-protein regulated Inward-Rectifier K⁺ channel, GIRK2) is a member of the family of inward rectifying K⁺ channels. 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 heterotetramers.
 
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_ir3.2 is a member of the K_ir3.x subfamily that includes four members (K_ir3.1- K_ir3.4). The K_ir3 family is characterized by the fact that the channels can be activated by neurotransmitters and other factors acting via the activation of G-protein coupled receptors. Binding of the corresponding ligand to the G-protein receptor induces the dissociation of Gα-GTP from the Gbg dimer. The latter directly binds to K_ir3 and activates the channel.^2,3
 
K_ir3.2 is mainly expressed in the brain, were it co-assembles with K_ir3.1 or K_ir3.3 and mediates the inhibitory effects of many neurotransmitters including opioid, adrenergic, muscarinic, dopaminergic and γ-aminobutyric acid (GABA).^2,3
 
Point mutations in the mouse K_ir3.2 channel cause the weaver (wv) phenotype, a neurological abnormality characterized by the abnormal ‘weaving’ of the mice when they walk, hence the name weaver which is due to a substantial loss of cerebellar granule neurons. These mice also display mild local motor hyperactivity, presumably caused by the degeneration of dopaminergic neurons in the substantia nigra, spontaneous seizures and male sterility.¹
 
A peptide toxin originating from the Apis mellifera bee venom, Tertiapin (#STT-250) was shown to be a potent blocker of K_ir3.2 containing channels (7 nM for K_ir3.2 alone and 5.4 nM for the K_ir3.1/3.2 combination).⁴