UGT1A1 tetramer transfers GlcA from UDP-GlcA to BMG to form BDG

Stable Identifier
R-HSA-9632038
Type
Reaction [transition]
Species
Homo sapiens
Compartment
Synonyms
bilirubin monoglucuronide + UDP-glucuronic acid => bilirubin diglucuronide + UDP
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The principal conjugate of bilirubin in bile is bilirubin diglucuronide (BDG). The monomeric forms of UGT1A1 (Bilirubin UDP-glucuronyltransferase 1) only conjugates the first step of bilirubin conjugation to form the monoglucuronide. A tetrameric form of UGT1A1 can transfer glucuronic acid (GlcA) to bilirubin (BIL) and bilirubin monoglucuronide (BMG) to form both the monoglucuronide and the diglucuronide (BDG) conjugates respectively (Peters & Jansen 1986, Gorden et al. 1983, Choudhury et al. 1981, Fevery et al. 1971). UGT1A4 is also able to catalyse the formation of BDG (Ritter et al. 1992).

Literature References
PubMed ID Title Journal Year
6654901 The hepatic microsomal formation of bilirubin diglucuronide

Gordon, ER, Sommerer, U, Goresky, CA

J Biol Chem 1983
4639028 Bilirubin conjugates in bile of man and rat in the normal state and in liver disease

Fevery, J, Van, Damme B, Michiels, R, De Groote, J, Heirwegh, KP

J Clin Invest 1972
6796486 Bilirubin mono- and diglucuronide formation by human liver in vitro: assay by high-pressure liquid chromatography

Chowdhury, JR, Chowdhury, NR, Wu, G, Shouval, R, Arias, IM

Hepatology 1981
1339448 A novel complex locus UGT1 encodes human bilirubin, phenol, and other UDP-glucuronosyltransferase isozymes with identical carboxyl termini

Ritter, JK, Chen, F, Sheen, YY, Tran, HM, Kimura, S, Yeatman, MT, Owens, IS

J. Biol. Chem. 1992
3082969 Microsomal UDP-glucuronyltransferase-catalyzed bilirubin diglucuronide formation in human liver

Peters, WH, Jansen, PL

J Hepatol 1986
Participants
Participant Of
hasEvent
Catalyst Activity
Catalyst Activity
Title
glucuronosyltransferase activity of UGT1A1 tetramer [endoplasmic reticulum membrane]
Physical Entity
Activity
Orthologous Events
Authored
Reviewed
Created
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