Sodium-dependent phosphate cotransporter 2B (SLC34A2) (SLC34A2)

Sodium-dependent phosphate cotransporter 2B (SLC34A2), commonly referred to as NPT2b, is a multi-pass membrane protein that serves as the primary mediator of active inorganic phosphate absorption in the human small intestine (UniProt: O95436). It functions by utilizing the sodium gradient across the apical membrane of enterocytes to transport phosphate into the cell, a process that is tightly regulated by dietary phosphate levels and hormonal signals such as 1,25-dihydroxyvitamin D3 (PubMed: 21831919). In patients with chronic kidney disease (CKD), the loss of renal phosphate excretion leads to hyperphosphatemia, which triggers secondary hyperparathyroidism and promotes extraosseous calcification, significantly increasing cardiovascular risk (NIH: PMC6070131). Consequently, SLC34A2 is a major therapeutic target for managing mineral metabolism; inhibiting this transporter reduces the total systemic burden of phosphate. While traditional therapies rely on phosphate binders to sequester ions in the gut lumen, newer pharmacological approaches include direct SLC34A2 inhibitors and indirect modulators like NHE3 inhibitors, which reduce paracellular phosphate permeability (PubMed: 31530577). These interventions are critical for maintaining phosphate balance and improving clinical outcomes in renal and metabolic disorders.

Other names

NPT2bNaPi-IIbSodium/phosphate cotransporter 2BSolute carrier family 34 member 2

Inhibition of active sodium-dependent phosphate transport via SLC34A2 or reduction of paracellular phosphate permeability via NHE3 inhibition.