protein_function: Heme oxygenase cleaves the heme ring at the alphamethene bridge to form biliverdin. Biliverdin is subsequentlyconverted to bilirubin by biliverdin reductase. Underphysiological conditions, the activity of heme oxygenase ishighest in the spleen, where senescent erythrocytes aresequestrated and destroyed. Exhibits cytoprotective effects sinceexcess of free heme sensitizes cells to undergo apoptosis.
HMOX1 (heme oxygenase (decycling) 1) is a human gene that encodes for the enzyme heme oxygenase 1. It is localized to chromosome 22. Heme oxygenase, an essential enzyme in heme catabolism, cleaves heme to form biliverdin, which is subsequently converted to bilirubin by biliverdin reductase, and carbon monoxide, a putative neurotransmitter. Heme oxygenase activity is induced by its substrate heme and by various nonheme substances. Heme oxygenase occurs as 2 isozymes, an inducible heme oxygenase-1 and a constitutive heme oxygenase-2. HMOX1 and HMOX2 belong to the heme oxygenase family.