HMOX1 (heme oxygenase (decycling) 1) is a human gene that encodes for the enzyme heme oxygenase 1 (EC Heme oxygenase mediates the first step of heme catabolism, it cleaves heme to form biliverdin.

Available structures
PDBOrtholog search: PDBe RCSB
AliasesHMOX1, HMOX1D, HO-1, HSP32, bK286B10, heme oxygenase 1
External IDsOMIM: 141250 MGI: 96163 HomoloGene: 31075 GeneCards: HMOX1
Gene location (Human)
Chromosome 22 (human)
Chr.Chromosome 22 (human)[1]
Chromosome 22 (human)
Genomic location for HMOX1
Genomic location for HMOX1
Band22q12.3Start35,380,361 bp[1]
End35,394,207 bp[1]
RNA expression pattern
PBB GE HMOX1 203665 at fs.png
More reference expression data
RefSeq (mRNA)



RefSeq (protein)



Location (UCSC)Chr 22: 35.38 – 35.39 MbChr 8: 75.09 – 75.1 Mb
PubMed search[3][4]
View/Edit HumanView/Edit Mouse

Heme oxygenase, an essential enzyme in heme catabolism, cleaves heme to form biliverdin, carbon monoxide, and ferrous iron.[5] The biliverdin is subsequently converted to bilirubin by biliverdin reductase. 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.[6]

The HMOX gene is located on the long (q) arm of chromosome 22 at position 12.3, from base pair 34,101,636 to base pair 34,114,748.

Related conditionsEdit

Anti-inflammatory effectEdit

The ability of oxygenase 1 to catabolize free heme and produce carbon monoxide (CO) gives its anti-inflammatory properties by up-regulation of interleukin 10 (IL-10) and interleukin 1 receptor antagonist (IL-1RA) expression.[7]

See alsoEdit


  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000100292 - Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000005413 - Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ Lehninger's Principles of Biochemistry, 5th Edition. New York: W.H. Freeman and Company. 2008. pp. 876. ISBN 978-0-7167-7108-1.
  6. ^ "Entrez Gene: HMOX1 heme oxygenase (decycling) 1".
  7. ^ Piantadosi CA, Withers CM, Bartz RR, MacGarvey NC, Fu P, Sweeney TE, Welty-Wolf KE, Suliman HB (May 2011). "Heme oxygenase-1 couples activation of mitochondrial biogenesis to anti-inflammatory cytokine expression". J. Biol. Chem. 286 (18): 16374–85. doi:10.1074/jbc.M110.207738. PMC 3091243. PMID 21454555.

Further readingEdit

External linksEdit

  • Overview of all the structural information available in the PDB for UniProt: P09601 (Heme oxygenase 1) at the PDBe-KB.