ABCC1

ABCC1, also known as MRP1, is an ATP-binding cassette transporter that mediates the efflux of a broad range of endogenous and xenobiotic substrates. In humans the ABCC1 gene encodes this transporter and is located on chromosome 16p13.11. ABCC1 is widely expressed in many tissues, with notable levels in the lungs, liver, kidney, intestines, and at the blood–brain barrier, contributing to cellular defense against toxicants.

Structurally, ABCC1 belongs to the ABCC subfamily and comprises two transmembrane domains and two cytoplasmic nucleotide-binding domains. It uses ATP hydrolysis to transport substrates from the cytoplasm to the extracellular space or into intracellular vesicles. Its transport activity is often linked to conjugated metabolites, including reduced glutathione (GSH), glucuronide and sulfate conjugates, biliary and bilirubin conjugates, and endogenous lipids such as leukotriene C4 and prostaglandins. It also transports several anticancer drugs, including certain anthracyclines and vinca alkaloids, contributing to multidrug resistance in tumor cells.

Clinical and biological relevance: Variation in ABCC1 expression or activity influences drug pharmacokinetics and toxicity, and polymorphisms have been studied in relation to cancer risk and treatment response. At physiological barriers such as the blood–brain barrier and placenta, ABCC1 limits drug penetration into protected compartments.

Research and therapeutic implications: ABCC1 is a focus of studies aimed at overcoming drug resistance, and selective inhibitors or modulators are explored to enhance chemotherapy efficacy, as well as to modulate transport of endogenous substrates in disease contexts.