Tissue Expression Pattern of Class II and Class V Genes Found in the Adh Complex on Mouse Chromosome 3

Abstract

The alcohol dehydrogenase enzymes in mice and humans are encoded by a linked group of genes in the same transcriptional orientation. The enzymes play important roles in alcohol metabolism and retinoid signaling and homeostasis. The expression patterns at the mRNA level of the mouse Adh4 (class II) gene and the recently identified Adh6a and Adh6b genes (class V) are now reported to complete this analysis for the entire family. Adh4 is expressed at high levels in liver and is detectable in small intestine and testes. Adh6b is expressed in liver but Adh6a is not. Adh6a is expressed at high levels in small intestine while Adh6b is not. Adh6a expression is detectable in the female adrenal and not at all in the male adrenal, but Adh6b is expressed at moderate levels in both sexes. Although Adh6a and Adh6b have expression patterns different from each other, neither expresses like any other gene in the complex, suggesting different control mechanisms and possibly different functions.

Expression Pattern, Ethanol‐Metabolizing Activities, and Cellular Localization of Alcohol and Aldehyde Dehydrogenases in Human Small Intestine

“…Two activity phenotypes of ADH2 in human duodenal/jejunal mucosae were identified by isoelectric focusing gels. Northern blot analyses have demonstrated that ADH2 mRNA is predominantly expressed in liver, followed by small intestine but considerably lower or undetectable in the other tissues examined, in human and rodents (Estonius et al., , ; Szalai et al., ). Interestingly, only 60% of the intestinal samples in the present study showed ADH2 activity bands.…”

Expression, Interaction, and Role of Pseudogene Adh6-ps1 in Cancer and other Disease Phenotypes

“…This group of genes has been reported to encode for 5 different classes of enzymes in identical transcriptional orientation, and these enzymes can reverse the oxidation of a handful of primary and secondary alcohols to their related ketones and aldehydes, thereby playing essential roles in alcohol metabolism, homeostasis, and retinoid signaling. 1 , 2 The mouse Adh1 gene and human ADH1A, ADH1B, and ADH1C genes encode class I enzymes responsible for ethanol metabolism; class III enzymes are encoded by Adh5 (mouse) and ADH5 (human) genes which are both involved in S-nitrosoglutathione metabolism. 1 , 2 Genes encoding class I and III as well as class IV (mouse Adh7, human ADH7) are all involved in retinoid signaling.…”

“… 1 , 2 The mouse Adh1 gene and human ADH1A, ADH1B, and ADH1C genes encode class I enzymes responsible for ethanol metabolism; class III enzymes are encoded by Adh5 (mouse) and ADH5 (human) genes which are both involved in S-nitrosoglutathione metabolism. 1 , 2 Genes encoding class I and III as well as class IV (mouse Adh7, human ADH7) are all involved in retinoid signaling. 2 …”

“… 1 , 2 Genes encoding class I and III as well as class IV (mouse Adh7, human ADH7) are all involved in retinoid signaling. 2 …”

“… 1 Some of the Adh genes have been reported to be expressed in the liver (Adh4, Adh6b) and can be detected in the testes and small intestine (Adh6b). 2 While much is unknown about pseudogene Adh6-ps1, a phylogenetic tree analysis of the transcriptional orientation suggests that Adh gene complex resulted from a duplication event, and that the gene complex in human and mouse have at least a gene for each of the 5 ADH classes. 1 Adh6-ps1 possibly belongs to ADH class V and is rather associated with the mouse gene cluster.…”