AHCY

S-adenosylhomocysteine hydrolase belongs to the adenosylhomocysteinase family. It catalyzes the reversible hydrolysis of S-adenosylhomocysteine (AdoHcy) to adenosine (Ado) and L-homocysteine (Hcy). Thus, it regulates the intracellular S-adenosylhomocysteine (SAH) concentration thought to be important for transmethylation reactions. Deficiency in this protein is one of the different causes of hypermethioninemia. Alternatively spliced transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jun 2009]

Adenosylhomocysteinase

Adenosylhomocysteine is a competitive inhibitor of S-adenosyl-L-methionine-dependent methyl transferase reactions; therefore adenosylhomocysteinase may play a key role in the control of methylations via regulation of the intracellular concentration of adenosylhomocysteine.

Chronic inflammatory response to antigenic stimulus
Circadian sleep/wake cycle
Methylation
One-carbon metabolic process
Response to hypoxia
Response to nutrient
S-adenosylhomocysteine catabolic process
S-adenosylmethionine cycle
Sulfur amino acid metabolic process

Cytoplasm; Melanosome. Identified by mass spectrometry in melanosome fractions from stage I to stage IV.

Hypermethioninemia with S-adenosylhomocysteine hydrolase deficiency (HMAHCHD): A metabolic disorder characterized by hypermethioninemia associated with failure to thrive, mental and motor retardation, facial dysmorphism with abnormal hair and teeth, and myocardiopathy.