Reaction: HNMT transfers CH3 group from AdoMet to Hist
- in pathway: Histidine catabolism
Histamine (Hist) plays important biological roles in cell-to-cell communication via by binding to histamine receptors and its local action is terminated primarily by methylation. Histamine is inactivated principally by two enzymes: histamine N-methyltransferase (HNMT) and diamine oxidase. HNMT uses the methyl donor AdoMet, methylates Hist to form methylhistamine (MetHist) (Yamauchi et al. 1994). The common polymorphism T105I correlates with high (T) or low (I) activity phenotypes (Horton et al. 2001, Rutherford et al. 2008).
Reaction - small molecule participants:
MeHist [cytosol]
AdoHcy [cytosol]
Hist [cytosol]
AdoMet [cytosol]
Reactome.org reaction link: R-HSA-175993
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Reaction input - small molecules:
histaminium
S-adenosyl-L-methionine zwitterion
Reaction output - small molecules:
N(tele)-methylhistamine
S-adenosyl-L-homocysteine zwitterion
Reactome.org link: R-HSA-175993