Solute carrier family 12 member 2 (NKCC1) (NKCC1)

Solute carrier family 12 member 2 (NKCC1) is a transmembrane protein that facilitates the electroneutral transport of one sodium, one potassium, and two chloride ions into the cell [2, 14]. It is ubiquitously expressed and serves as a master regulator of intracellular chloride homeostasis and cell volume, which is essential for transepithelial fluid secretion in the lungs, gastrointestinal tract, and exocrine glands [4, 12]. In the nervous system, NKCC1 is the primary chloride importer; its high expression in immature or pathological neurons results in elevated intracellular chloride levels, causing GABA to act as an excitatory neurotransmitter [10, 16]. This 'GABA switch' is a key factor in the pathophysiology of epilepsy, autism spectrum disorders, and schizophrenia [10, 13]. NKCC1 is also critical for inner ear function, where it maintains the ionic composition of the endolymph required for hearing [1, 8]. Pharmacologically, NKCC1 is inhibited by loop diuretics such as bumetanide and furosemide, which are traditionally used for hypertension and edema but are increasingly explored for treating neurological disorders by restoring inhibitory GABAergic signaling [5, 10]. Mutations in the SLC12A2 gene lead to severe neurodevelopmental conditions, including Kilquist syndrome and Delpire-McNeill syndrome, characterized by sensorineural deafness and intellectual disability [1, 12].

Other names

SLC12A2Bumetanide-sensitive sodium-(potassium)-chloride cotransporter 2BSC2Na-K-2Cl cotransporter 1Basolateral Na-K-Cl symporterBumetanide-sensitive sodium-(potassium)-chloride cotransporter 1BSC-2CCC1KILQSProtein phosphatase 1 regulatory subunit 141

Inhibition of the Na-K-2Cl cotransporter, blocking the electroneutral influx of sodium, potassium, and chloride ions into the cell.