title: Identification and functional characterization of a polymorphic oestrogen response element in the human coagulation factor IX gene promoter.
abstract: The liver expressed procoagulant factor IX (FIX) shows inter-individual variation in levels, some of which is heritable. Raised levels of FIX are associated with a thrombotic tendency. This study demonstrated that, in females but not males, part of this variation in FIX levels is due to polymorphic genotype at a locus in the factor IX gene (F9) promoter 698 bp upstream of the major transcription initiation site (-698C/T). The -698C allele (associated with higher FIX level) shows closer homology to a canonical ORE sequence and a higher binding affinity for oestrogen receptor alpha than the -698T allele. Reporter gene vectors were constructed with elements spanning residues -738 to +50 of the F9 promoter corresponding to wild type -698C and -698T alleles. A related series of vectors comprising three copies of the F9 ORE driving expression of a minimal synthetic promoter were also created. Transfection into the liver-derived HepG2 and erythroleukaemic K562 cell lines demonstrated increased levels of expression in the presence of oestrogenic factors when compared to those found in their absence; this stimulation was more pronounced in the non-liver derived K562 cell line and from the reporter vectors containing promoter elements corresponding to the -698C allele.
authors.affiliation: Academic Unit of Haematology, Division of Medicine and Biomedical Sciences, University of Sheffield, Sheffield, UK.
authors.forename: B
authors.initials: B
authors.lastname: Adams
authors.forename: A K
authors.initials: AK
authors.lastname: Western
authors.forename: P R
authors.initials: PR
authors.lastname: Winship
mesh_terms: D001483:Base Sequence; D002478:Cells, Cultured; D024202:Electrophoretic Mobility Shift Assay / Q000379:methods; D004967:Estrogens / Q000235:genetics*; D005164:Factor IX / Q000032:analysis / Q000235:genetics* / Q000378:metabolism; D005260:Female; D005822:Genetic Vectors; D006801:Humans; D020014:K562 Cells; D008297:Male; D008969:Molecular Sequence Data; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011960:Receptors, Estrogen / Q000378:metabolism; D020218:Response Elements; D012737:Sex Factors; D014162:Transfection
chemical_list: D004967:Estrogens; D011960:Receptors, Estrogen; D005164:Factor IX