{"id":3038,"date":"2026-08-22T21:14:16","date_gmt":"2026-08-22T20:14:16","guid":{"rendered":"https:\/\/seamlessbio.de\/?page_id=3038"},"modified":"2026-08-23T00:16:55","modified_gmt":"2026-08-22T23:16:55","slug":"what-is-abc-transporter","status":"publish","type":"page","link":"https:\/\/seamlessbio.de\/de\/what-is-abc-transporter\/","title":{"rendered":"What is an ABC Transporter?"},"content":{"rendered":"
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Quick Definition<\/p>\n

What is an ABC Transporter?:<\/strong> ATP-binding cassette (ABC) transporters are membrane proteins that use ATP hydrolysis to actively transport substrates across cell membranes against a concentration gradient. In pharmacokinetics, ABC efflux transporters \u2014 including P-gp, BCRP, BSEP, and the MRP family \u2014 control drug absorption, distribution, and elimination by pumping drugs out of cells at key biological barriers.<\/p>\n<\/div>\n

How do ABC transporters work?<\/h2>\n

ABC transporters have two transmembrane domains (TMDs) forming the substrate translocation pathway and two nucleotide-binding domains (NBDs) that bind and hydrolyse ATP. Transport cycle: (1) substrate binds to inward-facing TMD from cytoplasm; (2) ATP binds to both NBDs \u2192 dimerisation \u2192 TMDs shift to outward-facing conformation; (3) substrate released extracellularly; (4) ATP hydrolysis \u2192 transporter resets.<\/p>\n

Clinical significance of ABC transporter DDIs<\/h2>\n

Most important clinical examples: P-gp inhibition by ritonavir increases digoxin AUC by 86%; dual P-gp\/BCRP inhibition by eltrombopag doubles rosuvastatin exposure; BSEP inhibition by troglitazone caused fulminant hepatic failure and market withdrawal; P-gp induction by rifampicin reduces digoxin bioavailability 30\u201340%.<\/p>\n

Key Facts<\/h2>\n