Identification of a murine homolog of the human adenosine deaminase thymic enhancer

• Published in: Gene 1995-12, Vol.167 (1), p.261-266
• Main Authors: Brickner, Anthony G., Gossage, David L., Dusing, Mary R., Wiginton, Dan A.
• Format: Article
• Language: English
• Subjects: Adenosine Deaminase - genetics; Animals; Base Sequence; Enhancer Elements, Genetic; First intron; Gene Expression Regulation, Enzymologic; Genes; Humans; Introns; Mice; Molecular Sequence Data; nucleotide sequence; promoter; Promoter Regions, Genetic; Sequence Alignment; Sequence Homology, Nucleic Acid; T cell; T-Lymphocytes - enzymology; Thymus Gland - enzymology; Transfection; transient expression
• ISSN: 0378-1119; 1879-0038
• DOI: 10.1016/0378-1119(95)00673-7

We have identified a 236-bp first intron segment of the mouse adenosine deaminase gene ( ADA) that shares 71.1% identity with the human ADA thymic enhancer. This segment has the same natural orientation as the human enhancer and a relative location within the first intron very analogous to that of the human enhancer. Four highly conserved regions were defined within this segment, including a 72-bp region having 83.6% identity with a segment containing the critical human enhancer core. Several consensus binding sequences were also conserved within these regions. Transient transfection assays in human and murine T-cell lines revealed that a 1.8-kb murine genomic fragment harboring the 236-bp segment functions as a weak activator of both the human and mouse ADA promoters. In contrast, a 2.3-kb human enhancer fragment exhibited high-level activation in conjunction with either the human or mouse ADA promoter in both the MOLT 4 (human) and S49 (murine) T-cell lines. Interestingly, the murine ADA promoter is significantly stronger than the human promoter in driving cat expression in transient transfection assays in all the T-cell lines tested.