Adenosine deaminase: characterization and expression of a gene with a remarkable promoter.

Abstract

Cosmid clones containing the gene for human adenosine deaminase (ADA) were isolated. The gene is 32 kb long and split into 12 exons. The exact sizes and boundaries of the exon blocks including the transcription start sites were determined. The sequence upstream from this cap site lacks the TATA and CAAT boxes characteristic for eukaryotic promoters. Nevertheless, we have shown in a functional assay that a stretch of 135 bp immediately preceding the cap site has promoter activity. This 135‐bp DNA fragment is extremely rich in G/C residues (82%). It contains three inverted repeats that allow the formation of cruciform structures, a 10‐bp and a 16‐bp direct repeat and five G/C‐rich motifs (GGGCGGG) disposed in a strikingly symmetrical fashion. Some of these structural features were also found in the promoter region of other genes and we discuss their possible function. Knowledge of the exact positions of the intron‐exon boundaries allowed us to propose models for abnormal RNA processing that occurs in previously investigated ADA‐deficient cell lines.

Mutations in the human adenosine deaminase gene that affect protein structure and RNA splicing.

“…These additional 5' sequences agree with genomic sequence of this region (24,25) and indicate that there are multiple transcription initiation sites within the 5' end of the human ADA gene. S1 nuclease analysis of the 5' ends of ADA mRNA in our laboratory (J.C.S., unpublished data) has shown that there is a major initiation site, base 1 of the consensus sequence, and several very minor initiation sites.…”

“…We have previously reported a similar ADA cDNA sequence pADA3-3 (21). In both cases, the intron 7 sequence is identical to intron 7 of the normal ADA gene (24,25 we do not believe that the absence of exon 7 or the inclusion of intron 7 is relevant to ADA deficiency.…”

Cloning and characterization of the human gene for the α‐subunit of Gi2, a GTP‐binding signal transduction protein

“…Several characteristics of the Giza promoter, such as high G + C content, high frequency of GpC dinucleotides, multiple GC boxes, and lack of a TATA box are common to the promoters of ras [29,30] and 'housekeeping' genes, such as the hypoxanthine phosphoribosyl transferase [31], EGF receptor [32], HMG-CoA reductase [33], and adenosine deaminase [34] genes. These promoter characteristics are presumably important for allowing these genes to be ubiquitously expressed.…”

Mineralocorticoid and glucocorticoid receptors in the brain. Implications for ion permeability and transmitter systems

“…The absence of TATA boxes is common for promoters of 'housekeeping' genes; these genes often have multiple transcription initiation sites (Valerio et al, 1985). The transcription of a single gene from multiple promoters has important consequences for the fine regulation of gene expression, e.g.…”