Solute carrier family 12 member 5 (KCC2) (KCC2)

Solute carrier family 12 member 5 (KCC2) is a neuron-specific potassium-chloride cotransporter that serves as the primary mechanism for chloride extrusion in the mature central nervous system (Wikipedia, 2024). By maintaining low intracellular chloride levels, KCC2 ensures that the activation of GABA_A and glycine receptors leads to a hyperpolarizing influx of chloride ions, which is essential for fast synaptic inhibition (NIH, 2023). Dysregulation or downregulation of KCC2 is a common pathological feature in several neurological conditions, including epilepsy, neuropathic pain, and amyotrophic lateral sclerosis (ALS), where the resulting increase in intracellular chloride can cause GABAergic signaling to become excitatory (MDPI, 2023). This shift, known as disinhibition, contributes to neuronal hyperexcitability and network dysfunction (Frontiers, 2024). Therapeutic development focuses on KCC2 activators and positive allosteric modulators, such as CLP290, which aim to restore physiological chloride gradients and inhibitory tone (ResearchGate, 2021). Additionally, KCC2 plays structural roles in dendritic spine morphogenesis and synaptic plasticity independent of its transport function (NIH, 2011).

Other names

SLC12A5Potassium-chloride cotransporter 2Chloride potassium symporter 5hKCC2Electroneutral potassium-chloride cotransporter 2

Positive allosteric modulation of KCC2 activity, enhancement of KCC2 membrane expression, and indirect activation via inhibition of WNK/SPAK signaling pathways to restore chloride extrusion and GABAergic inhibition.