ClC-2 chloride channel (ClC-2)

ClC-2 is a voltage-gated chloride ion channel encoded by the CLCN2 gene. It is a member of the CLC family characterized by a homodimeric structure with each subunit forming an independent pore for selective passage of chloride ions across cell membranes. The protein contains transmembrane domains with conserved α-helices and two cytoplasmic CBS domains involved in regulation. ClC-2 is widely expressed throughout mammalian tissues—including brain (neurons and glia), heart, skeletal muscle, kidney, pancreas, liver, lung, gastrointestinal tract—and plays key roles in maintaining electrical excitability and ionic balance within cells. In neurons it helps regulate intracellular chloride concentration critical for inhibitory neurotransmission via GABA receptors; in glial cells it contributes to K+ uptake following intense neuronal activity. Mutations or dysfunctions in ClC-2 have been linked to neurological diseases such as certain epilepsies and leukodystrophies—especially when associated with accessory proteins like GlialCAM—or retinal degenerative disorders. The development of specific inhibitors like AK-42 has enabled more precise study but also highlights therapeutic challenges due to its broad physiological roles.[1][3][4][5]

Other names

Chloride channel protein 2CLCN2 (gene name)CLC-2Voltage-gated chloride channel 2

AK-42 and similar inhibitors block the selective passage of Cl– ions through the ClC-2 channel, thereby modulating neuronal excitability and ion homeostasis. This can affect processes such as GABAergic inhibition by altering intracellular chloride concentrations.[2]