Transcriptional activation of the human rod cGMP-phosphodiesterase beta-subunit gene is mediated by an upstream AP-1 element.
During photoactivation retinal cGMP-phosphodiesterase (PDE) mediates signal transduction in the photoreceptor outer segments. Mutations in the beta-subunit gene of rod-specific PDE (beta-PDE) have been associated with inherited retinal degeneration in a number of species, including human. Here we have investigated the proximal upstream sequences that participate in transcriptional activation of this gene. Transient transfections demonstrated that the sequence from -72 to +53 bp contained sufficient information to direct high levels of gene expression in cells of retinal origin. Deletion or mutagenesis of an AP-1 motif present in this region caused 90-95% reduction in reporter gene expression. By gel mobility shift assay we demonstrated specific interactions between putative nuclear transcription factors and this AP-1 element. These findings indicate that the proximal AP-1 site in the human beta-PDE promoter is functionally relevant and necessary for transcriptional activation of this gene.
Di Polo
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Jules Stein Eye Institute, UCLA School of Medicine, Los Angeles, CA 90095, USA.
Lerner
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Farber
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D015106:3',5'-Cyclic-GMP Phosphodiesterases / Q000737:chemistry / Q000235:genetics*; D001483:Base Sequence; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; D017931:DNA Primers / Q000235:genetics; D015870:Gene Expression; D006801:Humans; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009687:Nuclear Proteins / Q000378:metabolism; D010727:Phosphoric Diester Hydrolases; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011487:Protein Conformation; D012160:Retina / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism*; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D015533:Transcriptional Activation; D014162:Transfection
D017931:DNA Primers; D009687:Nuclear Proteins; D018808:Transcription Factor AP-1; D010727:Phosphoric Diester Hydrolases; D015106:3',5'-Cyclic-GMP Phosphodiesterases; D054707:Cyclic Nucleotide Phosphodiesterases, Type 6; C517431:PDE6B protein, human