{{.infobox .infobox-gene}}
| Symbol | SLC34A2 |
| Full Name | Solute Carrier Family 34 Member 2 (Sodium-Phosphate Transporter 2) |
| Chromosome | 4p15 |
| NCBI Gene ID | 10568 |
| OMIM | 604236 |
| Ensembl ID | ENSG00000140557 |
| UniProt ID | O75478 |
| Associated Diseases | Pulmonary alveolar proteinosis, Hypophosphatemia, Sarcoidosis |
The SLC34A2 gene encodes Sodium-Phosphate Transporter 2 (NaPi-IIb), a membrane protein that mediates phosphate uptake across epithelial cells [1]. NaPi-IIb is expressed in multiple tissues, including the lung, intestine, kidney, and brain, where it plays essential roles in phosphate homeostasis [2].
Phosphate is critical for numerous biological processes, including bone mineralization, energy metabolism (ATP), signal transduction, and nucleic acid synthesis. Proper phosphate balance is maintained through the coordinated action of intestinal absorption, renal reabsorption, and cellular uptake transporters like NaPi-IIb [3].
NaPi-IIb (SLC34A2) operates as a secondary active transporter, coupling phosphate (Pi) uptake to the inward sodium gradient. The stoichiometry is typically 3 Na⁺: 1 HPO₄²⁻ (or 2 Na⁺: 1 H₂PO₄⁻), making the transport electrogenic [4].
Key characteristics:
NaPi-IIb activity is regulated by:
NaPi-IIb is expressed in several tissues:
Phosphate is essential for neuronal function:
While not directly causative, phosphate dysregulation may contribute to:
SLC34A2 mutations cause pulmonary alveolar proteinosis (PAP), a condition characterized by accumulation of surfactant in the alveoli. While primarily a lung disease, PAP can have neurological complications due to:
Homozygous or compound heterozygous mutations in SLC34A2 cause PAP, characterized by:
SLC34A2 expression is altered in sarcoidosis, a multisystem granulomatous disorder. The transporter may play a role in the inflammatory response and granuloma formation [12].
While SLC34A2 mutations are not a common cause of hypophosphatemia, the transporter's role in phosphate homeostasis means it may contribute to phosphate balance disorders [13].
NaPi-IIb is a therapeutic target: