HMOX2 explained

Heme oxygenase 2 is an enzyme that in humans is encoded by the HMOX2 gene.^[1]

Function

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 (this enzyme) belong to the heme oxygenase family.^[2]

Further reading

• Bianchetti CM, Yi L, Ragsdale SW, Phillips GN . Comparison of Apo- and Heme-bound Crystal Structures of a Truncated Human Heme Oxygenase-2 . J Biol Chem . 282 . 52 . 37624–31 . 2007 . 17965015 . 2896506 . 10.1074/jbc.M707396200 . free .
• Wang J, Zhuang H, Doré S . Heme oxygenase 2 is neuroprotective against intracerebral hemorrhage. . Neurobiol. Dis. . 22 . 3 . 473–6 . 2006 . 16459095 . 10.1016/j.nbd.2005.12.009 . 43195015 .
• Wang J, Doré S . Heme oxygenase 2 deficiency increases brain swelling and inflammation after intracerebral hemorrhage . Neuroscience . 155 . 4 . 1133–41 . 2008 . 18674596 . 4696610 . 10.1016/j.neuroscience.2008.07.004 .
• Barañano DE, Snyder SH . Neural roles for heme oxygenase: Contrasts to nitric oxide synthase . Proc. Natl. Acad. Sci. U.S.A. . 98 . 20 . 10996–1002 . 2001 . 11572959 . 58673 . 10.1073/pnas.191351298 . 2001PNAS...9810996B . free .
• Doré S . Decreased activity of the antioxidant heme oxygenase enzyme: implications in ischemia and in Alzheimer's disease . Free Radic. Biol. Med. . 32 . 12 . 1276–82 . 2002 . 12057765 . 10.1016/S0891-5849(02)00805-5 .
• Kemp PJ . Hemeoxygenase-2 as an O2 sensor in K+ channel-dependent chemotransduction . Biochem. Biophys. Res. Commun. . 338 . 1 . 648–52 . 2005 . 16137652 . 10.1016/j.bbrc.2005.08.110 .
• Ishikawa K, Takeuchi N, Takahashi S, Matera KM, Sato M, Shibahara S, Rousseau DL, Ikeda-Saito M, Yoshida T . Heme oxygenase-2. Properties of the heme complex of the purified tryptic fragment of recombinant human heme oxygenase-2 . J. Biol. Chem. . 270 . 11 . 6345–50 . 1995 . 7890772 . 10.1074/jbc.270.11.6345 . free .
• Kutty RK, Kutty G, Rodriguez IR, Chader GJ, Wiggert B . Chromosomal localization of the human heme oxygenase genes: heme oxygenase-1 (HMOX1) maps to chromosome 22q12 and heme oxygenase-2 (HMOX2) maps to chromosome 16p13.3 . Genomics . 20 . 3 . 513–6 . 1994 . 8034330 . 10.1006/geno.1994.1213 .
• Maruyama K, Sugano S . Oligo-capping: a simple method to replace the cap structure of eukaryotic mRNAs with oligoribonucleotides . Gene . 138 . 1–2 . 171–4 . 1994 . 8125298 . 10.1016/0378-1119(94)90802-8 .
• Takahashi K, Hara E, Suzuki H, Sasano H, Shibahara S . Expression of heme oxygenase isozyme mRNAs in the human brain and induction of heme oxygenase-1 by nitric oxide donors . J. Neurochem. . 67 . 2 . 482–9 . 1996 . 8764571 . 10.1046/j.1471-4159.1996.67020482.x . 12552519 .
• Saito-Ohara F, Ikeuchi T, Matsumoto M, Kurata S . Assignment of the mouse heme oxygenase genes: heme oxygenase-1 (Hmox1) to chromosome 10 band C1 and heme oxygenase-2 (Hmox2) to chromosome 16 band B1 . Cytogenet. Cell Genet. . 77 . 3–4 . 180–1 . 1997 . 9284910 . 10.1159/000134570 .
• Suzuki Y, Yoshitomo-Nakagawa K, Maruyama K, Suyama A, Sugano S . Construction and characterization of a full length-enriched and a 5'-end-enriched cDNA library . Gene . 200 . 1–2 . 149–56 . 1997 . 9373149 . 10.1016/S0378-1119(97)00411-3 .
• Yoshiki N, Kubota T, Aso T . Expression and localization of heme oxygenase in human placental villi . Biochem. Biophys. Res. Commun. . 276 . 3 . 1136–42 . 2000 . 11027601 . 10.1006/bbrc.2000.3551 .
• Hanselmann C, Mauch C, Werner S . Haem oxygenase-1: a novel player in cutaneous wound repair and psoriasis? . Biochem. J. . 353 . Pt 3 . 459–66 . 2001 . 11171041 . 1221590 . 10.1042/0264-6021:3530459 .
• Appleton SD, Marks GS, Nakatsu K, Brien JF, Smith GN, Graham CH, Lash GE . Effects of hypoxia on heme oxygenase expression in human chorionic villi explants and immortalized trophoblast cells . Am. J. Physiol. Heart Circ. Physiol. . 284 . 3 . H853–8 . 2003 . 12578814 . 10.1152/ajpheart.00655.2002 .
• Galey D, Becker K, Haughey N, Kalehua A, Taub D, Woodward J, Mattson MP, Nath A . Differential transcriptional regulation by human immunodeficiency virus type 1 and gp120 in human astrocytes . J. Neurovirol. . 9 . 3 . 358–71 . 2003 . 12775419 . 10.1080/13550280390201119 . 22016092 .
• Zenclussen AC, Lim E, Knoeller S, Knackstedt M, Hertwig K, Hagen E, Klapp BF, Arck PC . Heme oxygenases in pregnancy II: HO-2 is downregulated in human pathologic pregnancies . Am. J. Reprod. Immunol. . 50 . 1 . 66–76 . 2004 . 14506930 . 10.1034/j.1600-0897.2003.00047.x . 35763984 .
• Boehning D, Moon C, Sharma S, Hurt KJ, Hester LD, Ronnett GV, Shugar D, Snyder SH . Carbon monoxide neurotransmission activated by CK2 phosphorylation of heme oxygenase-2 . Neuron . 40 . 1 . 129–37 . 2003 . 14527438 . 10.1016/S0896-6273(03)00596-8 . 11562548 . free .
• Appleton SD, Lash GE, Marks GS, Nakatsu K, Brien JF, Smith GN, Graham CH . Effect of glucose and oxygen deprivation on heme oxygenase expression in human chorionic villi explants and immortalized trophoblast cells . Am. J. Physiol. Regul. Integr. Comp. Physiol. . 285 . 6 . R1453–60 . 2004 . 14615405 . 10.1152/ajpregu.00234.2003 .

Notes and References

1. McCoubrey WK, Ewing JF, Maines MD . Human heme oxygenase-2: characterization and expression of a full-length cDNA and evidence suggesting that the two HO-2 transcripts may differ by choice of polyadenylation signal . Arch Biochem Biophys . 295 . 1 . 13–20 . Jun 1992 . 1575508 . 10.1016/0003-9861(92)90481-B . free .
2. Web site: Entrez Gene: HMOX2 heme oxygenase (decycling) 2.