HNMT

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. Multiple alternatively spliced transcript variants that encode different proteins have been found for this gene. [provided by RefSeq]

histamine N-methyltransferase

Inactivates histamine by N-methylation. Plays an important role in degrading histamine and in regulating the airway response to histamine.

Histamine catabolic process Source: UniProtKB
Histamine metabolic process Source: ARUK-UCL
Histidine catabolic process Source: Reactome
Methylation Source: UniProtKB
Respiratory gaseous exchange by respiratory system Source: ProtInc

Cytoplasm

Mental retardation, autosomal recessive 51 (MRT51):
A form of mental retardation, a disorder characterized by significantly below average general intellectual functioning associated with impairments in adaptive behavior and manifested during the developmental period.