Chloride potassium symporter 5

Potassium-chloride transporter member 5 (aka: KCC2 and SLC12A5) is a neuron-specific chloride potassium symporter responsible for establishing the chloride ion gradient in neurons through the maintenance of low intracellular chloride concentrations. It is a critical mediator of synaptic inhibition, cellular protection against excitotoxicity and may also act as a modulator of neuroplasticity. Potassium-chloride transporter member 5 is also known by the names: KCC2 (potassium chloride cotransporter 2) for its ionic substrates, and SLC12A5 for its genetic origin from the SLC12A5 gene in humans.

Animals with reduced expression of this transporter exhibit severe motor deficits, epileptiform activity, and spasticity. KCC2 knockout animals, in which KCC2 is completely absent, die postnatally due to respiratory failure.

Location

KCC2 is a neuron-specific membrane protein expressed throughout the central nervous system, including the hippocampus, hypothalamus, brainstem, and motoneurons of the ventral spinal cord.