Solute carrier organic anion transporter family member 1B3

Ideogram human chromosome 12

Solute Carrier Organic Anion Transporter Family Member 1B3 (SLCO1B3), also known as the Organic Anion Transporting Polypeptide 1B3 (OATP1B3), is a protein that in humans is encoded by the SLCO1B3 gene. This protein is a member of the organic anion transporter (OATP) family, which is crucial for the transport of a wide variety of endogenous and exogenous organic anions, including bile acids, steroid conjugates, thyroid hormones, and various pharmaceuticals across the cell membrane.

Function

SLCO1B3 is predominantly expressed in the liver and is located on the basolateral (sinusoidal) membrane of hepatocytes. It plays a significant role in the hepatic uptake of organic anions, particularly bile salts, from the blood. This process is essential for the detoxification and excretion of these substances via the bile. Additionally, SLCO1B3 is involved in the pharmacokinetics of many drugs by mediating their uptake into the liver, where they can be metabolized or excreted.

Clinical Significance

Variations in the SLCO1B3 gene can affect the function of the OATP1B3 protein, potentially altering the pharmacokinetics of drugs and increasing the risk of drug-induced toxicity. For example, certain polymorphisms in the SLCO1B3 gene have been associated with altered statin plasma levels, which can affect the efficacy and safety of statin therapy used in the treatment of hypercholesterolemia.

Furthermore, the expression of SLCO1B3 has been studied in various cancers, including hepatocellular carcinoma and prostate cancer. Changes in the expression levels of this transporter can influence the uptake and efficacy of chemotherapeutic agents, making SLCO1B3 a potential target for cancer therapy.

Genetic and Molecular Biology

The SLCO1B3 gene is located on chromosome 12 in humans. It encodes a protein that is 702 amino acids long and belongs to the OATP family, which is characterized by 12 transmembrane domains. These domains form a pore through which substrates can be transported across the cell membrane.

See Also

• Organic anion transporting polypeptides
• Hepatocyte
• Bile acid
• Pharmacokinetics
• Polymorphism (biology)
• Hepatocellular carcinoma
• Prostate cancer