The mutation in the mitochondrial aldehyde dehydrogenase (ALDH2) gene responsible for alcohol-induced flushing increases turnover of the enzyme tetramers in a dominant fashion - PubMed (original) (raw)

The mutation in the mitochondrial aldehyde dehydrogenase (ALDH2) gene responsible for alcohol-induced flushing increases turnover of the enzyme tetramers in a dominant fashion

Q Xiao et al. J Clin Invest. 1996.

Abstract

Deficiency in mitochondrial aldehyde dehydrogenase (ALDH2), a tetrameric enzyme, results from inheriting one or two ALDH2*2 alleles. This allele encodes a protein subunit with a lysine for glutamate substitution at position 487 and is dominant over the wild-type allele, ALDH2*1. The ALDH2*2-encoded subunit (ALDH2K) reduces the activity of ALDH2 enzyme in cell lines expressing the wild-type subunit (ALDH2E). In addition to this effect on the enzyme activity, we now report that ALDH2*2 heterozygotes had lower levels of ALDH2 immunoreactive protein in autopsy liver samples. The half-lives of ALDH2 protein in HeLa cell lines expressing ALDH2*1, ALDH2*2, or both were determined by the rate of loss of immunoreactive protein after inhibition of protein synthesis with puromycin and by pulse-chase experiments. By either measure, ALDH2E enzyme was very stable, with a half-life of at least 22 h. ALDH2K enzyme had an enzyme half-life of only 14 h. In cells expressing both subunits, most of the subunits assemble as heterotetramers, and these enzymes had a half-life of 13 h. Thus, the effect of ALDH2K on enzyme turnover is dominant. These studies indicate that the ALDH2*2 allele exerts its dominant effect both by interfering with the catalytic activity of the enzyme and by increasing its turnover. This represents the first example of a dominantly acting allele with this effect on a mitochondrial enzyme's turnover.

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References

    1. J Biol Chem. 1992 May 15;267(14):9858-67 - PubMed
    1. Nature. 1992 Jan 2;355(6355):33-45 - PubMed
    1. J Biol Chem. 1994 Feb 11;269(6):4401-8 - PubMed
    1. Cell. 1994 Apr 22;77(2):249-59 - PubMed
    1. J Biol Chem. 1994 May 13;269(19):13854-60 - PubMed

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