The current studies define the role of three distinct cis-elements in the proximal promoter of the rat farnesyl diphosphate (FPP) synthase gene. The three cis-elements, a sterol regulatory element 3 (SRE-3) flanked by an ATTGG motif (inverted CCAAT box), and a CCAAT box, form a sterol regulatory unit that is necessary and sufficient for sterol-regulated expression of FPP synthase promoter-reporter genes. FPP synthase promoter-reporter genes, that contain promoters with either wild-type nucleotide sequences or mutations in one or more of the three cis-elements, were transiently transfected into CV- 1 cells. The activity of the wild-type promoter-reporter gene increased when the cells were incubated in sterol-depleted media or when the cells were co- transfected with a plasmid encoding the mature form of SRE binding protein (SREBP-1a). The results with the mutant promoter-reporter genes demonstrated that all three cis-elements were necessary for normal expression/regulation of the reporter gene by either sterols or by co-expressed SREBP-1a. Gel mobility shift assays demonstrated that the synergistic binding of SREBP-1a to SRE-3 was dependent on the binding of recombinant nuclear factor Y (NF-Y) to the DNA, consistent with the in vivo regulation studies.
|Titolo:||Synergistic activation of transcription by nuclear factor Y and sterol regulatory element binding protein|
|Parole Chiave:||Alkyl and Aryl Transferases ; Animals ; Base Sequence ; CCAAT-Enhancer-Binding Proteins ; DNA-Binding Proteins ; Gene Expression Regulation, Enzymologic ; Genes, Reporter ; Geranyltranstransferase ; Molecular Sequence Data ; Nuclear Proteins ; Protein Binding ; Rats ; Sterol Regulatory Element Binding Protein 1 ; Transcription Factors ; Transcription, Genetic|
|Settore Scientifico Disciplinare:||Settore BIO/18 - Genetica|
|Data di pubblicazione:||apr-1998|
|Appare nelle tipologie:||01 - Articolo su periodico|