Mediates the Na(+)-independent uptake of organic anions . Transports the conjugated steroids 17-beta-glucuronosyl estradiol (17beta-estradiol 17-O-(beta-D-glucuronate) or E2G) and dehydroepiandrosterone 3-sulfate (DHEAS) at the smooth endoplasmic reticulum membrane (SER), granting access to metabolizing enzymes ( ). Contributes to the metabolism of bile acids such as taurocholate (cholyltaurine) and lithocholate, by functioning as a doorway between SER and cytosol, thereby decreasing their circulating levels and protecting the organism from their detergent properties . Regulates access or exit of drugs to the SER lumen .
Subcellular locations: Smooth endoplasmic reticulum membrane, Cell membrane, Endoplasmic reticulum membrane
Expressed in the perivenular areas (centrilobular) of the liver (at protein level).