Sodium-dependent phosphate transport protein 2B (NPT2b) (NPT2b)

Sodium-dependent phosphate transport protein 2B (NPT2b), encoded by the SLC34A2 gene, is a multi-pass membrane protein that functions as a symporter, moving three sodium ions for every one divalent phosphate ion across the cell membrane [1, 2, 5]. It is primarily expressed in the brush border membrane of the small intestine, where it mediates the majority of active transcellular phosphate absorption, and in the type II pneumocytes of the lung, where it plays a role in surfactant metabolism [1, 4, 9]. In the context of chronic kidney disease (CKD), NPT2b is a key therapeutic target for managing hyperphosphatemia, as its inhibition can significantly reduce the systemic absorption of dietary phosphate [11, 12]. Additionally, NPT2b is highly overexpressed in several malignancies, most notably epithelial ovarian cancer and non-small cell lung adenocarcinoma, making it an attractive tumor-associated antigen for targeted therapies such as antibody-drug conjugates (ADCs) [3, 4, 8]. While several ADCs and small-molecule inhibitors have entered clinical trials, challenges remain regarding gastrointestinal tolerability and the potential for pulmonary toxicity due to the transporter's physiological role in the lungs [4, 7, 14].

Other names

SLC34A2NaPi2bNaPi-2bNaPi-IIbNPTIIbSodium/phosphate cotransporter 2BSolute carrier family 34 member 2NAPI-3BPULAM

Inhibition of intestinal sodium-dependent phosphate cotransport; Targeted delivery of cytotoxic agents via antibody-drug conjugates (ADCs)