Characterization and regulation of the protein binding to a cis-acting element, RET 1, in the rat opsin promoter.
RET 1 is a binding site for retinal nuclear proteins located at -136 to -110 bp in the rat opsin promoter, as defined by DNase protection assays. A similar sequence is found in the upstream flanking regions of many other photoreceptor genes in mammals and other species, including Drosophila. A 7-base consensus sequence, CAATTAG, is found in these genes and has the binding activity of the longer RET 1 element. A 40-kDa protein that binds to RET 1 has been purified over 2 x 10(5)-fold to apparent homogeneity by affinity chromatography. The RET 1 binding activity is first detectable at E18 and increases during the first two postnatal weels, At embryonic ages the retarded bands show an altered mobility and at early postnatal ages two bands are detected, with the adult band increasing and the embryonic band decreasing in intensity. Treatment of early postnatal retinas with bFGF increased the binding activity in nuclear extracts and caused a shift in migration of the retarded band to a position characteristic of the embryonic form of the complex. The results support the hypothesis that RET 1-like elements play an important role in rod photoreceptor development.
Yu
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Department of Ophthalmology and Visual Science, Yale University School of Medicine, New Haven, CT, USA.
Barnstable
C J
CJ
D000818:Animals; D000831:Animals, Newborn; D001483:Base Sequence; D001665:Binding Sites; D002417:Cattle; D002454:Cell Differentiation; D002846:Chromatography, Affinity; D016384:Consensus Sequence; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005136:Eye Proteins / Q000302:isolation & purification / Q000378:metabolism*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D018507:Gene Expression Regulation, Developmental; D005796:Genes; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D051381:Rats; D012045:Regulatory Sequences, Nucleic Acid; D017948:Retinal Rod Photoreceptor Cells / Q000254:growth & development / Q000378:metabolism*; D017299:Rod Opsins / Q000235:genetics*; D016415:Sequence Alignment; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D014157:Transcription Factors / Q000378:metabolism*
D004268:DNA-Binding Proteins; D005136:Eye Proteins; D017299:Rod Opsins; D014157:Transcription Factors; D016222:Fibroblast Growth Factor 2