Histamine N-methyltransferase

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HNMT
Histamine n-methyltransferase1.png
Available structures
PDB Ortholog search: PDBe RCSB
Identifiers
Aliases HNMT, HMT, HNMT-S1, HNMT-S2, MRT51, histamine N-methyltransferase, Histamine N-methyltransferase
External IDs MGI: 2153181 HomoloGene: 5032 GeneCards: 3176
Orthologs
Species Human Mouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_001024074
NM_001024075
NM_006895

NM_080462

RefSeq (protein)

NP_001019245.1
NP_001019246.1
NP_008826.1

NP_536710.1

Location (UCSC) Chr 2: 137.96 – 138.02 Mb Chr 2: 24 – 24.05 Mb
PubMed search [1] [2]
Wikidata
View/Edit Human View/Edit Mouse
histamine N-methyltransferase
Identifiers
EC number 2.1.1.8
CAS number 9029-80-5
Databases
IntEnz IntEnz view
BRENDA BRENDA entry
ExPASy NiceZyme view
KEGG KEGG entry
MetaCyc metabolic pathway
PRIAM profile
PDB structures RCSB PDB PDBe PDBsum
Gene Ontology AmiGO / EGO

Histamine N-methyltransferase (HMT, HNMT) is an enzyme that in humans is encoded by the HNMT gene.[1]

Histamine N-methyltransferase is one of two enzymes involved in the metabolism of histamine, the other being diamine oxidase. Histamine N-methyltransferase catalyzes the methylation of histamine in the presence of S-adenosylmethionine (SAM) forming N-methylhistamine. HMT is present in most body tissues but is not present in serum.[2] Histamine N-methyltransferase is encoded by a single gene which has been mapped to chromosome 2.

Function[edit]

In mammals, histamine is metabolized by two major pathways: N(tau)-methylation via histamine N-methyltransferase and oxidative deamination via diamine oxidase. This gene encodes the first enzyme which is found in the cytosol and uses S-adenosyl-L-methionine as the methyl donor. In the mammalian brain, the neurotransmitter activity of histamine is controlled by N(tau)-methylation as diamine oxidase is not found in the central nervous system. A common genetic polymorphism affects the activity levels of this gene product in red blood cells.[1]

References[edit]

  1. ^ a b "Entrez Gene: Histamine N-methyltransferase". 
  2. ^ Brown DD, Tomchick R, Axelrod J (November 1959). "The distribution and properties of a histamine-methylating enzyme" (pdf). J. Biol. Chem. 234 (11): 2948–50. PMID 13804910. 

Further reading[edit]

External links[edit]

This article incorporates text from the United States National Library of Medicine, which is in the public domain.