Solute carrier organic anion transporter family member 1B1, 1B3, and 2B1 (OATP1B1/1B3/2B1)

The organic anion-transporting polypeptides OATP1B1, OATP1B3, and OATP2B1 are key uptake transporters located on the basolateral (sinusoidal) membrane of human hepatocytes. They belong to the solute carrier (SLC) superfamily and are responsible for the sodium-independent transport of a broad range of endogenous and exogenous organic anions from the blood into the liver. Endogenous substrates include bile acids, bilirubin, and various hormones, while exogenous substrates encompass many widely used drugs such as statins, antihypertensives, and chemotherapeutic agents. Genetic polymorphisms, particularly in the SLCO1B1 gene, or pharmacological inhibition of these transporters can lead to significantly increased systemic drug concentrations, increasing the risk of adverse effects like statin-induced myopathy. Consequently, they are critical targets for evaluating drug-drug interactions during pharmaceutical development and are subject to specific regulatory guidelines from agencies like the FDA and EMA.

Other names

Organic anion-transporting polypeptide 1B1Organic anion-transporting polypeptide 1B3Organic anion-transporting polypeptide 2B1SLCO1B1SLCO1B3SLCO2B1OATP-COATP-2OATP-8OATP-BLST-1LST-2LST-3

These proteins function as uptake transporters that facilitate the entry of organic anions into hepatocytes; drugs can act as substrates for transport or as inhibitors that block the uptake of other compounds.