title: The promoter region of the human type-I-DNA-topoisomerase gene. Protein-binding sites and sequences involved in transcriptional regulation.
abstract: We examined the promoter of the human type-I-DNA topoisomerase gene (hTOP1) for regions protected against DNase I digestion by nuclear proteins from HeLa or from adenovirus-transformed 293 cells. We identified ten protected DNA sequences within 580 bp of DNA upstream of the transcriptional-start sites and one additional site, which is located between the two clusters of transcriptional-start sites. Several of these protein-binding sites have significant similarities to recognition sequences of known transcription factors including factors Sp1, octamer transcription factor, cAMP-responsive-element-binding protein (CREB/ATF), NF-kappa B and members of the Myc-related family of basic/helix-loop-helix/leucine-zipper proteins. Other protein-binding sites show less or no similarities to known consensus sequences. We investigated the physiological significance of these protein-binding sites using a set of deletion and nucleotide-exchange mutants. We conclude that the expression of the hTOP1 gene is regulated by a complex network of negatively and positively acting transcription factors.
authors.affiliation: Division of Biology, University of Konstanz, Germany.
authors.forename: S
authors.initials: S
authors.lastname: Heiland
authors.forename: R
authors.initials: R
authors.lastname: Knippers
authors.forename: N
authors.initials: N
authors.lastname: Kunze
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D002461:Cell Line, Transformed; D004264:DNA Topoisomerases, Type I / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D017384:Sequence Deletion; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D014157:Transcription Factors; D004264:DNA Topoisomerases, Type I