bile salt export pump; ATP-binding cassette sub-family B member 11 (ABCB11 BSEP)

Function

• role in the ATP-dependent secretion of bile salts into the canaliculus of hepatocytes

Kinetic parameters:

• KM=30.4 uM for taurocholate
• Vmax=232 pmol/min/mg enzyme for taurocholate transport

Structure

• multifunctional polypeptide with two homologous halves, each containing an hydrophobic membrane-anchoring domain & an ATP binding cassette domain (ABC domain)
• belongs to the ABC transporter family, multidrug resistance exporter (TC 3.A.1.201) subfamily
• contains 2 ABC transmembrane type-1 domains; residues 62-385 & 755-1043
• contains 2 ABC transporter domains; residues 420-656 & 1078-1316

Compartment

membrane

Expression

• expressed predominantly, if not exclusively in the liver, where it was further localized to the canalicular microvilli & to subcanalicular vesicles of the hepatocytes by in situ (putative)

Pathology

• defects in ABCB11 are the cause of:
  • progressive familial intrahepatic cholestasis type 2
  • chronic intrahepatic cholestasis without obvious familial history of chronic liver disease
  • benign recurrent intrahepatic cholestasis type 2
• genetic variations in ABCB11 may play a role in drug-induced cholestasis

More general terms

• transmembrane 12 protein
• ATP-binding cassette sub-family B (ABC transporter-B, ABCB)
• phosphoprotein
• glycoprotein

Additional terms

• bile acid

Database

• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:8647
• OMIM: https://mirror.omim.org/entry/601847
• OMIM: https://mirror.omim.org/entry/603201
• OMIM: https://mirror.omim.org/entry/605479
• UniProt: http://www.uniprot.org/uniprot/O95342.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=8647