DNA binding specificity and function of retinoid X receptor alpha.
Retinoid X receptors are members of the erbA superfamily of ligand-inducible transcription factors. Similar to several other members of this gene family, retinoid X receptors are known to bind to the hexameric DNA sequence AGGTCA. After binding to a direct repeat of this hexamer with a one-base pair spacer, retinoid X receptor homodimers are able to activate transcription in the presence of the ligand 9-cis-retinoic acid. However, it is not known if AGGTCA represents the highest affinity binding site for retinoid X receptors. A combination of the electrophoretic mobility shift assay and polymerase chain reaction was used to isolate from a pool of random DNA those sequences that bind retinoid X receptors with highest affinity. This approach, combined with mutational analysis and DNA footprinting, led to the identification of the seven-base pair sequence GGGGTCA as the highest affinity retinoid X receptor binding site. A direct repeat of this sequence is substantially more active than a direct repeat of AGGTCA as a retinoid X response element.
Subauste
J S
JS
Division of Endocrinology and Metabolism, University of Michigan Medical Center, Ann Arbor 48109-0678.
Katz
R W
RW
Koenig
R J
RJ
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000378:metabolism*; D017931:DNA Primers; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011401:Promoter Regions, Genetic; D018168:Receptors, Retinoic Acid / Q000302:isolation & purification / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism*; D047488:Retinoid X Receptors; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*
D017931:DNA Primers; D004268:DNA-Binding Proteins; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D047488:Retinoid X Receptors; D014157:Transcription Factors; D004247:DNA