Reaction: UGT1A4 transfers GlcA from UDP-GlcA to BIL to form BMG
- in pathway: Heme degradation
Bilirubin (BIL) is a breakdown product of heme. Its accumulation in the blood can be fatal. It is highly lipophilic and thus requires conjugation to become more water soluble to aid excretion. Both UGT1A1 tetramer and UGT1A4 can transfer glucuronic acid (GlcA) to bilirubin to form either its monoglucuronide (BMG) or diglucuronide (BDG) conjugates (Bosma et al. 1994, Ritter et al. 1992, Peters & Jansen 1986, Gorden et al. 1983, Choudhury et al. 1981, Fevery et al. 1971).
Reaction - small molecule participants:
BMG [endoplasmic reticulum lumen]
UDP [endoplasmic reticulum lumen]
BIL [endoplasmic reticulum lumen]
UDP-GlcA [endoplasmic reticulum lumen]
BMG [endoplasmic reticulum lumen]
UDP [endoplasmic reticulum lumen]
BIL [endoplasmic reticulum lumen]
UDP-GlcA [endoplasmic reticulum lumen]
Reactome.org reaction link: R-HSA-159194
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Reaction input - small molecules:
bilirubin(2-)
UDP-alpha-D-glucuronate(3-)
bilirubin(2-)
UDP-alpha-D-glucuronate(3-)
Reaction output - small molecules:
mono(glucosyluronic acid)bilirubin
UDP
mono(glucosyluronic acid)bilirubin
UDP
Reactome.org link: R-HSA-159194