SLC22A11

Antiporter that mediates the transport of conjugated steroids and other specific organic anions at the basal membrane of syncytiotrophoblast and at the apical membrane of proximal tubule epithelial cells, in exchange for anionic compounds. May be responsible for placental absorption of fetal-derived steroid sulfates such as estrone sulfate (E1S) and the steroid hormone precursor dehydroepiandrosterone sulfate (DHEA-S), as well as clearing waste products and xenobiotics from the fetus. Maybe also be involved in placental urate homeostasis. Facilitates the renal reabsorption of organic anions such as urate and derived steroid sulfates. Organic anion glutarate acts as conteranion for E1S renal uptake. Possible transport mode may also include DHEA-S/E1S exchange. Also interacts with inorganic anions such as chloride and hydroxyl ions, therefore possible transport modes may include E1S/Cl(-), E1S/OH(-), urate/Cl(-) and urate/OH(-). Also mediates the transport of prostaglandin E2 (PGE2) and prostaglandin F2-alpha (PGF2-alpha) and may be involved in their renal excretion. Also able to uptake anionic drugs, diuretics, bile salts and ochratoxin A. Mediates the unidirectional efflux of glutamate and aspartate. Glutamate efflux down its transmembrane gradient may drive SLC22A11/OAT4-mediated placental uptake of E1S..

Function from UniProtKB (Q9NSA0), read 2026-09-23. CC BY 4.0.