Aldehyde dehydrogenase 6 family, member A1

Last updated
ALDH6A1
Identifiers
Aliases ALDH6A1 , MMSADHA, MMSDH, Aldehyde dehydrogenase 6 family, member A1, aldehyde dehydrogenase 6 family member A1
External IDs OMIM: 603178 MGI: 1915077 HomoloGene: 4082 GeneCards: ALDH6A1
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_005589
NM_001278593
NM_001278594

NM_134042
NM_001313967

RefSeq (protein)

NP_001265522
NP_001265523
NP_005580

NP_001300896
NP_598803

Location (UCSC) Chr 14: 74.06 – 74.08 Mb Chr 12: 84.48 – 84.5 Mb
PubMed search [3] [4]
Wikidata
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Methylmalonate-semialdehyde dehydrogenase [acylating], mitochondrial (MMSDH) is an enzyme that in humans is encoded by the ALDH6A1 gene. [5] [6]

Contents

This protein belongs to the aldehyde dehydrogenases family of proteins. This enzyme plays a role in the valine and pyrimidine catabolic pathways. The product of this gene, a mitochondrial methylmalonate semialdehyde dehydrogenase, catalyzes the irreversible oxidative decarboxylation of malonate and methylmalonate semialdehydes to acetyl- and propionyl-CoA. Methylmalonate semialdehyde dehydrogenase deficiency is characterized by elevated beta-alanine, 3-hydroxypropionic acid, and both isomers of 3-amino and 3-hydroxyisobutyric acids in urine organic acids. [6] Methylmalonate semialdehyde dehydrogenase deficiency is caused by mutations in this gene and the resulting protein. [7]

Structure

The ALDH6A1 gene is mapped onto 14q24.3, between markers D14S71 and D14S986, and has an exon count of 12. [8] [6] The mRNA expression levels of this gene are highest in the kidney and liver, although mRNA levels have been found in many other tissues. The mature protein that this gene translates in humans is 503 amino acids long, which is similar to other enzymes of this family, which all comprise around 500 amino acids. This enzyme localizes to the mitochondria. Unlike other mitochondrial entry sequences, this does not contain as many arginine residues, and is in fact slightly longer. [7]

Function

MMSDH has esterase activity, which is characteristic of the enzymes in the Aldehyde Dehydrogenase family. It is more specifically involved in the valine and thymine catabolism pathways. When the enzyme acts on valine, (S)-3-hydroxyisobutyric acid is generated as an intermediate; this then undergoes oxidation by the enzyme 3-hydroxyisobutyrate dehydrogenase to form (S)-methylmalonic semialdehyde (MMSA). In thymine catabolism, the enzymatic reaction produces (R)-aminoisobutyric acid (AIBA), which is then deaminated to (R)-methylmalonic semialdehyde. These two enantiomers of MMSA are substrates for MMSDH, which catalyzes their oxidative decarboxylation to propionyl-CoA. [9] Both NAD+ and CoA act as cofactors with the enzyme, although they work in opposite directions; NAD+ works to protect the enzyme against proteolysis, but CoA esters diminish that effect. [10]

Clinical significance

Mutations in the ALDH6A1 gene are associated with methylmalonate semialdehyde dehydrogenase deficiency, a rare autosomal recessive inborn error of metabolism with a highly variable phenotype. The disease is passed through autosomal recessive genetics. There have been many individual and familial case studies of this deficiency and the mutations that cause it. Some patients with this disease may be asymptomatic, whereas others show global developmental delay, nonspecific dysmorphic features, and delayed myelination on brain imaging. Meanwhile, some cases have been only identified through elevated levels of various acidic metabolites in the urine, notably 3-hydroxyisobutyric acid. [7] [11] This can result from an identified a homozygous 1336G-A transition in the gene, resulting in a change in the 446th residue from glycine to arginine. [12] Another case study, a child from consanguineous patients, presented as significant hypotonia in infancy, poor feeding, and dysmorphic facial features, including narrowed, downslanting palpebral fissures, short convex nose with depressed nasal bridge, microphthalmia, cataracts, and adducted thumbs. Brain imaging showed delayed myelination and thinning of the corpus callosum. Laboratory studies showed 3-hydroxyisobutyric aciduria and mild lactic acidosis. [13] Many case studies since then have presented similar symptoms, although the symptoms may be milder. [14] The mutations identified are generally heterozygous missense mutations: S262Y, P62S, Y172H and R535C. [7]

Related Research Articles

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<span class="mw-page-title-main">2-Hydroxyglutaric aciduria</span> Medical condition

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<span class="mw-page-title-main">Succinic semialdehyde dehydrogenase deficiency</span> Rare disorder involving deficiency in GABA degradation

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<span class="mw-page-title-main">Methylmalonyl-CoA mutase</span>

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<span class="mw-page-title-main">ALDH2</span> Enzyme

Aldehyde dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ALDH2 gene located on chromosome 12. This protein belongs to the aldehyde dehydrogenase family of enzymes. Aldehyde dehydrogenase is the second enzyme of the major oxidative pathway of alcohol metabolism. Two major liver isoforms of aldehyde dehydrogenase, cytosolic and mitochondrial, can be distinguished by their electrophoretic mobilities, kinetic properties, and subcellular localizations.

<span class="mw-page-title-main">ACADSB</span> Protein-coding gene in the species Homo sapiens

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<span class="mw-page-title-main">Aldehyde dehydrogenase 3 family, member A1</span> Protein-coding gene in the species Homo sapiens

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Succinate-semialdehyde dehydrogenase, mitochondrial is an enzyme that in humans is encoded by the ALDH5A1 gene.

<span class="mw-page-title-main">Aldehyde dehydrogenase 18 family, member A1</span> Protein-coding gene in the species Homo sapiens

Delta-1-pyrroline-5-carboxylate synthetase (P5CS) is an enzyme that in humans is encoded by the ALDH18A1 gene. This gene is a member of the aldehyde dehydrogenase family and encodes a bifunctional ATP- and NADPH-dependent mitochondrial enzyme with both gamma-glutamyl kinase and gamma-glutamyl phosphate reductase activities. The encoded protein catalyzes the reduction of glutamate to delta1-pyrroline-5-carboxylate, a critical step in the de novo biosynthesis of proline, ornithine and arginine. Mutations in this gene lead to hyperammonemia, hypoornithinemia, hypocitrullinemia, hypoargininemia and hypoprolinemia and may be associated with neurodegeneration, cataracts and connective tissue diseases. Alternatively spliced transcript variants, encoding different isoforms, have been described for this gene. As reported by Bruno Reversade and colleagues, ALDH18A1 deficiency or dominant-negative mutations in P5CS in humans causes a progeroid disease known as De Barsy Syndrome.

<span class="mw-page-title-main">L2HGDH</span>

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<span class="mw-page-title-main">Alpha-aminoadipic semialdehyde synthase</span>

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<span class="mw-page-title-main">ALDH7A1</span> Protein-coding gene in the species Homo sapiens

Aldehyde dehydrogenase 7 family, member A1, also known as ALDH7A1 or antiquitin, is an enzyme that in humans is encoded by the ALDH7A1 gene. The protein encoded by this gene is a member of subfamily 7 in the aldehyde dehydrogenase gene family. These enzymes are thought to play a major role in the detoxification of aldehydes generated by alcohol metabolism and lipid peroxidation. This particular member has homology to a previously described protein from the green garden pea, the 26g pea turgor protein. It is also involved in lysine catabolism that is known to occur in the mitochondrial matrix. Recent reports show that this protein is found both in the cytosol and the mitochondria, and the two forms likely arise from the use of alternative translation initiation sites. An additional variant encoding a different isoform has also been found for this gene. Mutations in this gene are associated with pyridoxine-dependent epilepsy. Several related pseudogenes have also been identified.

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References

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  2. 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000021238 - 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. Kedishvili NY, Popov KM, Rougraff PM, Zhao Y, Crabb DW, Harris RA (Sep 1992). "CoA-dependent methylmalonate-semialdehyde dehydrogenase, a unique member of the aldehyde dehydrogenase superfamily. cDNA cloning, evolutionary relationships, and tissue distribution". The Journal of Biological Chemistry. 267 (27): 19724–9. doi: 10.1016/S0021-9258(18)41835-2 . PMID   1527093.
  6. 1 2 3 "Entrez Gene: ALDH6A1 aldehyde dehydrogenase 6 family, member A1".
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  8. Chambliss KL, Gray RG, Rylance G, Pollitt RJ, Gibson KM (Jul 2000). "Molecular characterization of methylmalonate semialdehyde dehydrogenase deficiency". Journal of Inherited Metabolic Disease. 23 (5): 497–504. doi:10.1023/A:1005616315087. PMID   10947204. S2CID   9714122.
  9. Kedishvili NY, Popov KM, Rougraff PM, Zhao Y, Crabb DW, Harris RA (Sep 1992). "CoA-dependent methylmalonate-semialdehyde dehydrogenase, a unique member of the aldehyde dehydrogenase superfamily. cDNA cloning, evolutionary relationships, and tissue distribution". The Journal of Biological Chemistry. 267 (27): 19724–9. doi: 10.1016/S0021-9258(18)41835-2 . PMID   1527093.
  10. Kedishvili NY, Popov KM, Harris RA (Oct 1991). "The effect of ligand binding on the proteolytic pattern of methylmalonate semialdehyde dehydrogenase". Archives of Biochemistry and Biophysics. 290 (1): 21–6. doi:10.1016/0003-9861(91)90586-8. PMID   1898092.
  11. Pollitt RJ, Green A, Smith R (1985). "Excessive excretion of beta-alanine and of 3-hydroxypropionic, R- and S-3-aminoisobutyric, R- and S-3-hydroxyisobutyric and S-2-(hydroxymethyl)butyric acids probably due to a defect in the metabolism of the corresponding malonic semialdehydes". Journal of Inherited Metabolic Disease. 8 (2): 75–9. doi:10.1007/bf01801669. PMID   3939535. S2CID   6335599.
  12. Gray RG, Pollitt RJ, Webley J (Aug 1987). "Methylmalonic semialdehyde dehydrogenase deficiency: demonstration of defective valine and beta-alanine metabolism and reduced malonic semialdehyde dehydrogenase activity in cultured fibroblasts". Biochemical Medicine and Metabolic Biology. 38 (1): 121–4. doi:10.1016/0885-4505(87)90069-7. PMID   3117077.
  13. Shield JP, Gough R, Allen J, Newbury-Ecob R (Jul 2001). "3-Hydroxyisobutyric aciduria: phenotypic heterogeneity within a single family". Clinical Dysmorphology. 10 (3): 189–91. doi:10.1097/00019605-200107000-00007. PMID   11446412.
  14. Sass JO, Walter M, Shield JP, Atherton AM, Garg U, Scott D, Woods CG, Smith LD (May 2012). "3-Hydroxyisobutyrate aciduria and mutations in the ALDH6A1 gene coding for methylmalonate semialdehyde dehydrogenase". Journal of Inherited Metabolic Disease. 35 (3): 437–42. doi:10.1007/s10545-011-9381-x. PMID   21863277. S2CID   6911924.

Further reading