ATP-binding cassette transporter family (ABC transporter) (ABC transporter)

The ATP-binding cassette (ABC) transporter family is one of the largest and most ancient protein superfamilies, found in all extant phyla from bacteria to humans (Wikipedia, 2024; NIH, 2002). These transmembrane proteins utilize the energy of ATP binding and hydrolysis to actively transport a diverse array of substrates—including ions, lipids, sterols, metabolic products, and drugs—across cellular and organelle membranes (UniProt, 2024; IUPHAR, 2025). In humans, the family consists of 48-49 members divided into seven subfamilies (ABCA through ABCG), playing vital roles in physiological processes such as cholesterol homeostasis and the maintenance of the blood-brain barrier (NIH, 2002; Frontiers in Pharmacology, 2019). Clinically, ABC transporters are critical as they mediate the absorption and excretion of many drugs, and their overexpression is a primary mechanism of multidrug resistance (MDR) in cancer (NIH, 2024). Furthermore, mutations in ABC genes are linked to numerous genetic disorders, such as cystic fibrosis (CFTR/ABCC7), Tangier disease (ABCA1), and Stargardt disease (ABCA4) (NIH, 2002; ResearchGate, 2001).

Other names

ABC superfamilyTraffic ATPasesABC proteinsATP-powered pumps

ATP-dependent primary active transport of substrates across membranes; inhibition of efflux to reverse drug resistance; potentiation or correction of protein folding/function (e.g., CFTR modulators); regulation of ion channel activity (e.g., ABCC8/9).