Biology:ETHE1

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Short description: Protein-coding gene in the species Homo sapiens

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A representation of the 3D structure of the protein myoglobin showing turquoise α-helices.
Generic protein structure example

Protein ETHE1, mitochondrial, also known as "ethylmalonic encephalopathy 1 protein" and "per sulfide dioxygenase", is a protein that in humans is encoded by the ETHE1 gene located on chromosome 19.[1]

Structure

The human ETHE1 gene consists of 7 exons and encodes for a protein that is approximately 27 kDa in size.

Function

This gene encodes a protein that is expressed mainly in the gastrointestinal tract, but also in several other tissues such as the liver and the thyroid.[1]

The ETHE1 protein is thought to localize primarily to the mitochondrial matrix[2][3] and functions as a sulfur dioxygenase. Sulfur deoxygenates are proteins that function in sulfur metabolism. The ETHE1 protein is thought to catalyze the following reaction:

sulfur + O2 + H2O [math]\displaystyle{ \rightleftharpoons }[/math] sulfite + 2 H+ (overall reaction)
(1a) glutathione + sulfur [math]\displaystyle{ \rightleftharpoons }[/math] S-sulfanylglutathione (glutathione persulfide, spontaneous reaction)
(1b) S-sulfanylglutathione + O2 + H2O [math]\displaystyle{ \rightleftharpoons }[/math] glutathione + sulfite + 2 H+[2]

and requires iron[4] and possibly glutathione[4] as cofactors. The physiological substrate of ETHE1 is thought to be glutathione persulfide,[4] an intermediate metabolite involved in hydrogen sulfide degradation.


Clinical significance

Mutations in ETHE1 gene are thought to cause ethylmalonic encephalopathy,[3][5] a rare inborn error of metabolism. Patients carrying ETHE1 mutations have been found to exhibit lower activity of ETHE1 and affinity for the ETHE1 substrate.[4] Mouse models of Ethe1 genetic ablation likewise exhibited reduced sulfide dioxygenase catabolism and cranial features of ethylmalonic encephalopathy.[2] Decrease in sulfide dioxygenase activity results in abnormal catabolism of hydrogen sulfide, a gas-phase signaling molecule in the central nervous system,[4] whose accumulation is thought to inhibit cytochrome c oxidase activity in the respiratory chain of the mitochondrion.[2] However, other metabolic pathways may also be involved that could exert a modulatory effect on hydrogen sulfide toxicity.[6]

Interactions

ETHE1 has been shown to interact with RELA.[7]

References

  1. 1.0 1.1 "Entrez Gene: ETHE1 ethylmalonic encephalopathy 1". https://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=23474. 
  2. 2.0 2.1 2.2 2.3 "Loss of ETHE1, a mitochondrial dioxygenase, causes fatal sulfide toxicity in ethylmalonic encephalopathy". Nat. Med. 15 (2): 200–5. 2009. doi:10.1038/nm.1907. PMID 19136963. 
  3. 3.0 3.1 "Ethylmalonic encephalopathy is caused by mutations in ETHE1, a gene encoding a mitochondrial matrix protein". Am. J. Hum. Genet. 74 (2): 239–52. 2004. doi:10.1086/381653. PMID 14732903. 
  4. 4.0 4.1 4.2 4.3 4.4 "Characterization of patient mutations in human persulfide dioxygenase (ETHE1) involved in H2S catabolism". J. Biol. Chem. 287 (53): 44561–7. 2012. doi:10.1074/jbc.M112.407411. PMID 23144459. 
  5. "Encephalopathy, Ethylmalonic". Johns Hopkins University. http://www.omim.org/entry/602473. 
  6. "Multiple sources of metabolic disturbance in ETHE1-related ethylmalonic encephalopathy". J. Inherit. Metab. Dis. 33 (Suppl 3): S443–53. 2010. doi:10.1007/s10545-010-9227-y. PMID 20978941. 
  7. "A novel protein overexpressed in hepatoma accelerates export of NF-kappa B from the nucleus and inhibits p53-dependent apoptosis". Cancer Cell 2 (4): 335–46. Oct 2002. doi:10.1016/S1535-6108(02)00152-6. PMID 12398897. 

Further reading