Synthesis of high specific activity [3H]-9-cis-retinoic acid and its application for identifying retinoids with unusual binding properties.
all-trans-Retinoic acid is known to bind to the retinoic acid receptors (RARs) resulting in an increase in their transcriptional activity. In contrast, recently identified 9-cis-retinoic acid (9-cis-RA), which is an additional endogenous RA isomer, is capable of binding to both RARs and retinoid X receptors (RXRs). These distinct properties have raised questions as to the biological role governed by these two retinoic acid isomers and the set of target genes that they regulate. Herein, we report the synthesis of high specific activity [3H]-9-cis-RA and its application to study the ligand-binding properties of the various retinoid receptor subtypes. We examined the binding properties of RARs and RXRs for a series of synthetic retinoids and compared the ligand-binding properties of these arotinoid analogs with their ability to regulate gene expression via the retinoid receptors in a cotransfection assay. The utilization of the [3H]-9-cis-RA competitive binding assay and the cotransfection assay has made it possible to rapidly identify important structural features of retinoids leading to increased selectivity for either the RAR or RXR receptor subtypes.
Boehm
M F
MF
Department of Medicinal Chemistry, Ligand Pharmaceuticals, Incorporated, San Diego, California 92121.
McClurg
M R
MR
Pathirana
C
C
Mangelsdorf
D
D
White
S K
SK
Hebert
J
J
Winn
D
D
Goldman
M E
ME
Heyman
R A
RA
D000818:Animals; D016367:Baculoviridae / Q000235:genetics; D001565:Benzoates / Q000378:metabolism; D001667:Binding, Competitive; D008745:Methylation; D015394:Molecular Structure; D009036:Moths; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D018168:Receptors, Retinoic Acid / Q000235:genetics / Q000378:metabolism*; D011994:Recombinant Proteins / Q000378:metabolism; D047488:Retinoid X Receptors; D012176:Retinoids / Q000378:metabolism; D013329:Structure-Activity Relationship; D014157:Transcription Factors; D014162:Transfection; D014212:Tretinoin / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D014316:Tritium
D001565:Benzoates; D018160:Receptors, Cytoplasmic and Nuclear; D018168:Receptors, Retinoic Acid; D011994:Recombinant Proteins; D047488:Retinoid X Receptors; D012176:Retinoids; D014157:Transcription Factors; D014316:Tritium; D014212:Tretinoin; C038864:4-(2-(5,6,7,8-tetrahydro-5,5,8,8-tetramethyl-2-naphthalenyl)-1-propenyl)benzoic acid