title: Sequence requirements for transcriptional arrest in exon 1 of the human adenosine deaminase gene.
abstract: We have previously demonstrated that a transcriptional arrest site exists in exon 1 of the human adenosine deaminase (ADA) gene and that this site may play a role in ADA gene expression (Z. Chen, M. L. Harless, D. A. Wright, and R. E. Kellems, Mol. Cell. Biol. 10:4555-4564, 1990). Sequences involved in this process are not known precisely. To further define the template requirements for transcriptional arrest within exon 1 of the human ADA gene, various ADA templates were constructed and their abilities to confer transcriptional arrest were determined following injection into Xenopus oocytes. The exon 1 transcriptional arrest signal functioned downstream of several RNA polymerase II promoters and an RNA polymerase III promoter, implying that the transcriptional arrest site in exon 1 of the ADA gene is promoter independent. We identified a 43-bp DNA fragment which functions as a transcriptional arrest signal. Additional studies showed that the transcriptional arrest site functioned only in the naturally occurring orientation. Therefore, we have identified a 43-bp DNA fragment which functions as a transcriptional arrest signal in an orientation-dependent and promoter-independent manner. On the basis of our findings, we hypothesize that tissue-specific expression of the ADA gene is governed by factors that function as antiterminators to promote transcriptional readthrough of the exon 1 transcriptional arrest site.
authors.affiliation: Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas.
authors.forename: Z
authors.initials: Z
authors.lastname: Chen
authors.forename: J W
authors.initials: JW
authors.lastname: Innis
authors.forename: M H
authors.initials: MH
authors.lastname: Sun
authors.forename: D A
authors.initials: DA
authors.lastname: Wright
authors.forename: R E
authors.initials: RE
authors.lastname: Kellems
mesh_terms: D000243:Adenosine Deaminase / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D004247:DNA; D005091:Exons; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012320:RNA Polymerase III / Q000235:genetics; D015183:Restriction Mapping; D013698:Templates, Genetic; D014158:Transcription, Genetic; D014981:Xenopus
chemical_list: D004247:DNA; D012320:RNA Polymerase III; D000243:Adenosine Deaminase