Renal sodium, potassium and chloride non-electrogenic ion symporter that mediates the transepithelial NaCl reabsorption in the thick ascending limb and plays an essential role in the urinary concentration and volume regulation (PubMed:21321328). It can substitute NH4(+) for K(+), enabling NH4(+) apical transmembrane transport in the medullary thick ascending limb (MTAL). This function is crucial for maintaining ammonium homeostasis by the kidney, particularly during metabolic acidosis (By similarity). . This is the function of ENSG00000074803 (SLC12A1, solute carrier family 12 member 1).