title: Characterization of the decay-accelerating factor gene promoter region.
abstract: Decay-accelerating factor (DAF) expression modulates susceptibility of cells to autologous complement attack. To characterize the regulatory region controlling DAF gene transcription, genomic DNA extending from 815 base pairs (bp) upstream to approximately 4 kilobases downstream of DAF's AUG codon (designated +1) was cloned and sequenced. The 5' flanking sequence showed 59-76% G + C content (-355 to +1), at least one GC box(es) (-135 to -131), and variable length sequences (from -629 to -285) conforming to the motifs TCCTCC and TCn. Nuclease S1 digestions and primer extensions localized a major transcriptional start site to -82/-81, 38 bp downstream of a possible TATA variant, (A)TTTAA. In COS cell transfections, the sequence encompassing -815 to -67 functioned 2.5% as efficiently as the Rous sarcoma virus 3' long terminal repeat, but following deletion upstream of -355 its activity increased approximately 4-fold. Two octanucleotides exhibiting partial homology to phorbol 12-myristate 13-acetate (PMA) and cAMP responsive elements (PREs and CREs, respectively) were detected, and the respective modulators enhanced transcriptional efficiency 2- and approximately 10-fold, respectively. Thus, the DAF gene promoter (i) exhibits sequences resembling both conventional and unconventional transcriptional control elements, (ii) possesses a region with negative regulatory activity, and (iii) responds to PMA and cAMP induction presumably via PRE- and CRE-like enhancer elements.
authors.affiliation: Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106.
authors.forename: U K
authors.initials: UK
authors.lastname: Ewulonu
authors.forename: L
authors.initials: L
authors.lastname: Ravi
authors.forename: M E
authors.initials: ME
authors.lastname: Medof
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D018958:CD55 Antigens; D002872:Chromosome Deletion; D002878:Chromosomes, Human, Pair 1; D003001:Cloning, Molecular; D003169:Complement Inactivator Proteins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D015723:Gene Library; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014162:Transfection
chemical_list: D018958:CD55 Antigens; D003169:Complement Inactivator Proteins; D008565:Membrane Proteins; D015345:Oligonucleotide Probes