Involved in actively transporting phosphate into cells via Na(+) cotransport.
Subcellular locations: Apical cell membrane
Localized at the brush border membranes of enterocytes.
Highly expressed in lung. Also detected in pancreas, kidney, small intestine, ovary, testis, prostate and mammary gland. In lung, it is found in alveolar type II cells but not in bronchiolar epithelium.