Center for Bioinformatics
Oxidoreductases | Transferases | Hydrolases | Lyases | Isomerases | Ligases

Basic Information

Enzyme Number

Official Name

heme oxygenase

Name from literature

Heme oxygenase

Pathway from literature

CO generation,degrades heme/ production of bilirubin/ heme degradation pathway

Pathway from KEGG

Metabolism of Cofactors and Vitamins; Porphyrin and chlorophyll metabolism; map00860


Rat (10116)

Genome localization

10q12[79239 ], 19p11[24451 ],


Requires NAD(P)H and EC, NADPH---hemoprotein reductase. The terminal oxygen atoms that are incorporated into the carbonyl groups of pyrrole rings A and B of biliverdin are derived from two separate oxygen molecules [4]. The third oxygen molecule provides the oxygen atom that converts the alpha-carbon to CO. The central iron is kept in the reduced state by NAD(P)H.

Rate-limiting Description

"Heme oxygenase (HO) catalyzes the rate-limiting enzymatic step of heme degradation and regulates the cellular heme content." (10692503)

"Heme oxygenase (HO) is the rate-limiting enzyme in the catabolism of heme to biliverdin, carbon monoxide (CO), and free iron." (10727990)

Regulatory Information

Regulatory type







"briefly removing glucose from cultured cardiac fibroblasts induces COX-2 and HO-1 expression via generation of ROS and p38 MAPK phosphorylation" (15158123)


"up-regulation of HO-1 by non-steroidal anti-inflammatory drugs (NSAIDs) is mediated through NSAID-dependent activation (phosphorylation) of p38 mitogen-activated protein kinase" (16945925)

Gene ontology

Gene ontology

GO:0043619 (P) regulation of transcription from RNA polyme... [P06762 ];
GO:0005783 (C) endoplasmic reticulum [O70453, P06762, P23711 ];
GO:0004392 (F) heme oxygenase (decyclizing) activity [O70453, P06762, P23711 ];
GO:0008219 (P) cell death [P06762 ];
GO:0042542 (P) response to hydrogen peroxide [P06762 ];
GO:0005506 (F) iron ion binding [O70453, P06762, P23711 ];
GO:0019899 (F) enzyme binding [P06762 ];
GO:0006788 (P) heme oxidation [O70453, P06762, P23711 ];
GO:0051090 (P) regulation of transcription factor activity [P06762 ];
GO:0005792 (C) microsome [O70453, P06762, P23711 ];
GO:0005634 (C) nucleus [P06762 ];
GO:0055114 (P) oxidation reduction [O70453, P06762, P23711 ];

Subcellular localization


endoplasmic reticulum [O70453, P06762, P23711 ];

microsome [O70453, P06762, P23711 ];



O70453; P06762; P23711

Entrez Gene

24451; 79239

  Copyright 2009, Center for Bioinformatics 
  Last Modified: 2009-03-24  
  Design by Zhao Min