SLC5A9 Gene – SGLT4 Sodium/Glucose Cotransporter | NCBI, UniProt, OMIM

SLC5A9 encodes the sodium/glucose cotransporter 4 (SGLT4), a member of the solute carrier family 5. SGLT4 mediates the electrogenic transport of glucose and galactose across the plasma membrane, driven by an inward sodium gradient. It is primarily expressed in the small intestine and kidney, where it contributes to dietary sugar absorption and renal glucose reabsorption. The gene is located on chromosome 1p33 and is distinct from other SGLT family members in its substrate specificity and tissue distribution.

Tissue Expression

Cell Line Expression

Hotspot Mutations

Mutation functional classification

• REACT:21273 – SLC-mediated transmembrane transport

• REACT:15518 – Transport of glucose and other sugars

• bile salts and organic acids

• metal ions and amine compounds

• KEGG:04964 – Proximal tubule bicarbonate reclamation (indirect via sodium gradient)

SGLT4 (UniProt Q2M3G0) is a 672-amino acid integral membrane protein with 14 transmembrane helices. It functions as a sodium/glucose cotransporter with a 2:1 Na+:glucose stoichiometry. The protein is localized to the apical membrane of enterocytes and renal proximal tubule cells. It exhibits lower affinity for glucose compared to SGLT1 but can also transport galactose and mannose. Post-translational modifications include N-glycosylation at Asn-248, which is essential for proper trafficking to the plasma membrane.