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Functional polymorphism in the alcohol dehydrogenase 3 (ADH3) promoter
J J Hedberg1, M Backlund, P Strömberg
1Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm, Sweden.
Pharmacogenetics
|December 12, 2001
Summary
Genetic variants in the ADH3 gene promoter affect formaldehyde metabolism. These ADH3 gene promoter variations influence enzyme expression and individual capacity to process formaldehyde.
Area of Science:
- Genetics
- Biochemistry
- Toxicology
Background:
- The ADH3 gene encodes alcohol dehydrogenase 3 (ADH3), crucial for formaldehyde detoxification.
- ADH3 is highly conserved and expressed across tissues, playing a vital role in scavenging formaldehyde.
Purpose of the Study:
- To identify allelic variants in the ADH3 gene promoter and exons.
- To investigate the functional impact of identified promoter variants on ADH3 gene expression and protein binding.
Main Methods:
- PCR amplification and Single-Strand Conformation Polymorphism (SSCP) analysis of ADH3 gene promoter and exons.
- DNA sequencing, allele-specific PCR for frequency determination in diverse populations.
- Reporter gene assays and electrophoretic mobility shift assays (EMSA) to assess promoter activity and protein interactions.
Main Results:
- No variants found in ADH3 exons 5, 6, and 7.
- Four base pair exchanges identified in the ADH3 promoter region: -197 (GG>AA), -79 (G>A), and +9 (C>T).
- The C+9>T+9 variant significantly decreased transcriptional activity and nuclear protein binding in HeLa cells, with T+9 being the rarest allele (1.5% in Swedes).
Conclusions:
- Identified ADH3 promoter variants, particularly C+9>T+9, can alter ADH3 enzyme expression levels.
- These genetic variations may influence an individual's efficiency in metabolizing formaldehyde, impacting susceptibility.
- Further research into ADH3 variants can elucidate personalized formaldehyde metabolism capacities.
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