P-glycoprotein family

P-Glycoprotein (P-gp), a member of the adenosine triphosphate (ATP)-binding cassette family of membrane transporters, is encoded by the human multidrug-resistance (MDRl, ABCBl) gene (15). This integral membrane protein serves as an... 

Other mechanisms of interaction have also been reported, such as altered activity of other enzymes within the CYP450 family (14—17). Moreover, GFJ may also inhibit the intestinal P-glycoprotein (P-gp)-mediated efflux transport of drugs such as cyclosporine to increase its oral bioavailability (18-21). GFJ and other fruit juices have recently been shown to be potent in vitro inhibitors of a number of organic anion-transporting polypeptides (OATPs) (22,23). 

BSEP also known as sister-P-glycoprotein (SPGP) was originally cloned from pig liver (185). BSEP is localized on the canalicular membrane of hepa-tocytes and is responsible for the secretion of bile salts across the canalicular membrane into bile. BSEP appears to be the predominant bile salt efflux system for hepatocytes, and is a critical component in the enterohepatic circulation of bile acids. A number of mutations in the transporter were found to the basis for progressive familial intrahepatic cholestasis type 2 (PFIC2) (186-188). Mutations found in PFIC2 patients include frameshifts, missense mutations, and premature termination codons. Most PFIC2 patients lack immunohistochemically detectable BSEP in their liver. Recently, seven... 

Endicott JA, Sarangi F, Ling V. Complete cDNA sequences encoding the Chinese hamster P-glycoprotein gene family. DNA Seq 1991 2(2) 89-101. 

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