Abstract
The vitamin A derivative retinoic acid exerts its effects on transcription through two distinct classes of nuclear receptors, the retinoic acid receptor (RAR) and the retinoid X receptor (RXR). We provide evidence that expression of the gene for cellular retinol-binding protein type II (CRBPII), a key protein in the intestinal absorption of vitamin A, is dramatically up-regulated by retinoic acid in the presence of RXR but not RAR. This regulation is conferred through a specific cis element in the CRBPII promoter that contains five nearly perfect tandem repeats of the sequence AGGTCA spaced by a single nucleotide. The discovery of this new RX response element provides a means for distinguishing between the two retinoid receptor systems and suggests that an RXR-mediated pathway exists for modulating vitamin A metabolism.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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Base Sequence
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Carrier Proteins / physiology*
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Cell Line
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DNA Mutational Analysis
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DNA-Binding Proteins / physiology*
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Gene Expression Regulation* / drug effects
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Genes
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In Vitro Techniques
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Molecular Sequence Data
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Oligonucleotides / chemistry
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Promoter Regions, Genetic*
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Protein Binding
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RNA, Messenger / genetics
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Receptors, Retinoic Acid
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Regulatory Sequences, Nucleic Acid
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Retinol-Binding Proteins / genetics*
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Retinol-Binding Proteins, Cellular
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Transcription Factors / physiology*
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Transcription, Genetic
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Tretinoin / pharmacology
Substances
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Carrier Proteins
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DNA-Binding Proteins
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Oligonucleotides
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RNA, Messenger
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Receptors, Retinoic Acid
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Retinol-Binding Proteins
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Retinol-Binding Proteins, Cellular
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Transcription Factors
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Tretinoin