Heme Oxygenase 2 is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Heme oxygenase 2 (HMOX2, HO-2) is a constitutively expressed enzyme that catalyzes the degradation of heme into biliverdin, carbon monoxide, and free iron. Unlike its inducible counterpart HMOX1, HMOX2 provides basal heme degradation capacity and serves important neuroprotective functions in the central nervous system.
Heme Oxygenase 2 is a protein. This page describes its structure, normal nervous system function, role in neurodegenerative disease, and potential as a therapeutic target.
Heme oxygenase 2 (HMOX2, HO-2) is a constitutively expressed enzyme that catalyzes the degradation of heme into biliverdin, carbon monoxide, and free iron. Unlike its inducible counterpart HMOX1, HMOX2 provides basal heme degradation capacity and serves important neuroprotective functions in the central nervous system.
Structure and Function
Molecular Architecture
HMOX2 is a 316-amino acid protein with several key domains[@maines1997]:
N-terminal membrane anchor: Anchors to endoplasmic reticulum
Heme-binding pocket: Contains the catalytic site
Histidine-rich region: Potential metal binding site
[Maines MD, The heme oxygenase system: a regulator of second messenger gases (1997)](https://pubmed.ncbi.nlm.nih.gov/9083067/)
[Ryter SW et al, Heme oxygenase-1 and -2: genetic analysis of their roles in cell stress defense (2002)](https://pubmed.ncbi.nlm.nih.gov/12087450/)
[Maines MD, Gibbs PE, 30 some years of heme oxygenase: from a "molecular wrecking ball" to a "mesmerizing" trigger of cellular events (2005)](https://pubmed.ncbi.nlm.nih.gov/15776369/)
[Schipper HM et al, Heme oxygenase-1 and neurodegeneration: expanding frontiers of a neuroprotective mechanism (2009)](https://pubmed.ncbi.nlm.nih.gov/19874220/)
[Dang TN et al, Role of HMOX2 in brain iron homeostasis and neurodegeneration (2011)](https://pubmed.ncbi.nlm.nih.gov/22137329/)
[Baranano DE, Snyder SH, Neural roles for heme oxygenase: contrasts to nitric oxide synthase (2001)](https://pubmed.ncbi.nlm.nih.gov/11529433/)
[Calabrese V et al, Heme oxygenase in Alzheimer's disease brain: implications for antioxidant strategies (2006)](https://pubmed.ncbi.nlm.nih.gov/17077708/)
[Wang J, Doré S, Heme oxygenase-2: a critical regulator of heme-mediated oxidative stress in the brain (2009)](https://pubmed.ncbi.nlm.nih.gov/19206520/)
[Maines MD, Carbon monoxide: an emerging regulator of cGMP in the brain (2023)](https://pubmed.ncbi.nlm.nih.gov/36635988/)
[Queiroga CS et al, Carbon monoxide and the brain: beyond neurotransmission (2019)](https://pubmed.ncbi.nlm.nih.gov/31018297/)
[Maines MD et al, Heme oxygenase-2: characterization of the gene and its role in cellular stress defense (1994)](https://pubmed.ncbi.nlm.nih.gov/8076765/)
[Chen YH et al, Heme oxygenase-2 gene polymorphisms and risk of Parkinson's disease (2012)](https://pubmed.ncbi.nlm.nih.gov/22487698/)
[Motterlini R, Foresti R, Heme oxygenase-1 as a target for drug discovery (2014)](https://pubmed.ncbi.nlm.nih.gov/24887091/)
[Duvigneau JC et al, Heme oxygenase-2: novel regulator of brain iron homeostasis (2018)](https://pubmed.ncbi.nlm.nih.gov/30172720/)
[Nandar W, Connor JR, Ferroportin and iron regulation in neurodegeneration (2019)](https://pubmed.ncbi.nlm.nih.gov/30987100/)