What are P-glycoproteins?
P-glycoproteins are part of a larger superfamily of efflux transporters found in the gut, gonads, kidneys, biliary system, brain and other organs named the ATP-binding cassette family (ABCs). The nomenclature for both superfamilies can be found at http://www.genenames.org/cgi-bin/hgnc_search.pl. Similar to P450 CYPs and UGTs, the nomenclature follows the family, subfamily and isoform convention in which an integer represents the family (e.g., 1, 2), a letter, the subfamily (e.g., A, B, C) and an integer, the isoform (e.g., 1,2). Members of the ABC family all have the same ABC designation since they are all in a single family and the first integer is skipped. This is followed by the subfamily letter and isoform integer (e.g., ABCB1). According to the nomenclature, P-gps are part of a subfamily B of the ABC superfamily, and it has been designated as ABCB1.
