OATP1A2

OATP1A2, or organic anion transporting polypeptide 1A2, is a membrane transporter protein that belongs to the OATP/SLCO family. It mediates the sodium-independent uptake of a broad range of endogenous and exogenous organic anions, as well as some neutral compounds. The protein is encoded by the SLCO1A2 gene in humans.

In humans, SLCO1A2 is expressed in multiple tissues, including the intestinal epithelium, liver, kidney, and at the blood–brain barrier. Its presence at these sites supports roles in intestinal absorption, hepatic uptake, renal clearance, and the disposition of substrates within the central nervous system.

OATP1A2 transports amphipathic organic anions such as bile acid conjugates, steroid conjugates, thyroid hormones, and various drugs and xenobiotics. As part of the intestinal and hepatic uptake systems, it contributes to first-pass absorption and organ-specific uptake, and it can influence brain exposure to certain substrates.

Genetic variation in SLCO1A2 can alter transporter activity, with several identified polymorphisms showing reduced function in some individuals. The clinical significance of these variants is substrate- and context-dependent. Expression and activity may also be modulated by physiological conditions and concomitant drug exposure, leading to potential drug–drug interactions.

Clinically, variation in OATP1A2 activity can contribute to interindividual differences in pharmacokinetics and tissue distribution of substrates, as well as to the overall pharmacological response. Research continues to clarify its precise role in drug disposition and disease states.