title: A nuclear protein in mesangial cells that binds to the promoter region of the platelet-derived growth factor-A chain gene. Induction by phorbol ester.
abstract: Mesangial cells predominantly express platelet-derived growth factor (PDGF)-A chain mRNA and release PDGF. Mesangial cell PDGF-A chain mRNA abundance is regulated by several agents including phorbol esters. We have recently demonstrated that induction of PDGF-A chain mRNA abundance in response to phorbol 12-myristate 13-acetate is primarily due to gene transcription. We have now analyzed the 5'-flanking region of the PDGF-A chain promoter to identify DNA binding protein(s) which have the potential to regulate PDGF-A chain gene transcription in human mesangial cells. DNase I footprint analysis of the 5'-flanking region of the PDGF-A chain promoter identifies a DNase I protected region at the location -82 to -102 corresponding to the sequence 5'-GGCCCGGAATCCGGGGGAGGC-3'. Therefore, nuclear extracts from human mesangial cells contain a protein, PDGF-A-BP-1, that binds to a DNA sequence (-82 to -102) in the promoter region of the PDGF-A chain gene. Gel mobility shift analysis using labeled oligomer corresponding to the binding site for PDGF-A-BP-1 indicates that PDGF-A-BP-1 is induced by phorbol ester in mesangial cells as well as fat-storing cells (> 20 fold). Egr-1 protein does not bind to labeled PDGF-A-BP-1 oligomer and does not compete with the binding of PDGF-A-BP-1. In addition, SP-1 binding sequence does not compete with the binding sequence of the mesangial cell protein. PDGF-A-BP-1 appears to represent a novel protein which is induced by phorbol ester and thus has the potential for an important role in the transcriptional regulation of the PDGF-A chain gene in mesangial cells and other vascular pericytes.
authors.affiliation: Department of Medicine, University of Texas Health Science Center at San Antonio.
authors.forename: B
authors.initials: B
authors.lastname: Bhandari
authors.forename: U O
authors.initials: UO
authors.lastname: Wenzel
authors.forename: F
authors.initials: F
authors.lastname: Marra
authors.forename: H E
authors.initials: HE
authors.lastname: Abboud
mesh_terms: D001483:Base Sequence; D001665:Binding Sites; D001667:Binding, Competitive; D002478:Cells, Cultured; D004247:DNA / Q000737:chemistry; D003850:Deoxyribonuclease I; D015870:Gene Expression / Q000187:drug effects*; D005920:Glomerular Mesangium / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism*; D015345:Oligonucleotide Probes; D010982:Platelet-Derived Growth Factor / Q000096:biosynthesis* / Q000235:genetics; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014157:Transcription Factors / Q000378:metabolism*
chemical_list: D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; D010982:Platelet-Derived Growth Factor; D014157:Transcription Factors; C075278:platelet-derived growth factor A; D004247:DNA; D003850:Deoxyribonuclease I; D013755:Tetradecanoylphorbol Acetate