ABCtransportøren

ABCtransportøren is a term used in Danish biology to denote the ATP-binding cassette (ABC) transporters, a large and evolutionarily conserved family of membrane proteins that use energy from ATP hydrolysis to move substrates across cellular membranes. The core feature, reflected in the name, is the presence of two nucleotide-binding domains (NBDs) that bind and hydrolyze ATP, and typically two transmembrane domains (TMDs) that form the substrate pathway.

ABCtransportøren proteins can function as importers or exporters, depending on the organism and substrate; in bacteria many act as uptake systems, while most eukaryotic family members export xenobiotics, lipids or metabolic products. Substrates range from lipids, peptides and bile acids to drugs and toxins. In humans, several subfamilies mediate essential physiological processes: ABCA and ABCG members participate in lipid transport; ABCC members include CFTR (ABCC7), a chloride channel; ABCA1 mutations cause Tangier disease; ABCD1 defects cause X-linked adrenoleukodystrophy. The family is classified into eight subfamilies (ABCA–ABC G).

The mechanism involves ATP binding to the NBDs, triggering conformational changes in the TMDs that translocate the substrate across the membrane. Discovery and naming: the term ABC transporter arose from early work in the 1970s–1980s, with the first clinically relevant transporter, P-glycoprotein (ABCB1), linked to multidrug resistance. Importance: ABCtransportøren proteins are central to physiology and pharmacology, influence drug disposition and resistance, and are targets for therapies aimed at modulating transporter activity.