Molecular and functional analysis of the XPBC/ERCC-3 promoter: Transcription activity is dependent on the integrity of an Sp1 binding element.
The human XPBC/ERCC-3 gene, which corrects the excision-repair defect in xeroderma pigmentosum group B cells and the UV-sensitive CHO mutant 27-1 cells, appears to be expressed constitutively in various cell types and tissues. We have analysed the structure and functionality of the XPBC/ERCC-3 promoter. Transcription of the XPBC/ERCC-3 gene is initiated from heterogeneous sites, with a major startpoint mapped at position -54 (relative to the translation start codon ATG). The promoter region does not possess classical TATA and CAAT elements, but it is GC-rich and contains three putative Sp1-binding sites. In addition, there are two elements related to the cyclic AMP (cAMP)-response element (CRE) and the 12-O-tetradecanoyl phorbol-13-acetate-response element (TRE) in the 5'-flanking region. Transient expression analysis of XPBC/ERCC-3 promoter-CAT chimeric plasmids revealed that a 127-bp fragment, spanning position -129 to -3, is minimally required for the promoter activity. Transcription of the XPBC/ERCC-3 promoter depends on the integrity of a putative Sp1-binding site in close proximity to the major cap site. Band shift assays showed that this putative Sp1-binding site can interact specifically with a nuclear factor, most likely transcription factor Sp1 (or an Sp1-like factor) in vitro.
|Keywords||0 (Recombinant Fusion Proteins), 0 (Transcription Factor, Sp1), Animals, Base Sequence, Binding Sites/genetics, CHO Cells, DNA Repair/*genetics, Hamsters, Hela Cells, Human, Molecular Sequence Data, Promoter Regions (Genetics)/*genetics, Recombinant Fusion Proteins/genetics/metabolism, Regulatory Sequences, Nucleic Acid, Support, Non-U.S. Gov't, Transcription Factor, Sp1/*metabolism, Xeroderma Pigmentosum/enzymology/*genetics|
Ma, L., Weeda, G., Jochemsen, A.G., Bootsma, D., Hoeijmakers, J.H.J., & van der Eb, A.J.. (1992). Molecular and functional analysis of the XPBC/ERCC-3 promoter: Transcription activity is dependent on the integrity of an Sp1 binding element.. Nucleic Acids Research, 20, 217–224. Retrieved from http://hdl.handle.net/1765/3035