Retinoic acid receptor isotype specificity in F9 teratocarcinoma stem cells results from the differential recruitment of coregulators to retinoic response elements.
The retinoic acid receptor (RAR) alpha, beta(2), and gamma isotypes each regulate specific subsets of target genes in F9 teratocarcinoma stem cells. We used chromatin immunoprecipitation assays to monitor the association of RARgamma, retinoic X receptor (RXR) alpha, and coregulators with the RARbeta(2), Hoxa1, and Cyp26A1 retinoic acid response elements (RAREs) in F9 wild type and RARalpha, -beta(2), and -gamma null cells. Additionally we quantitatively monitored expression of the corresponding mRNAs. We demonstrated that the association of RARgamma and/or RXRalpha with a RARE was not sufficient for retinoic acid (RA)-mediated transcription of the corresponding target gene. However, the ability of RARgamma and/or RXRalpha to recruit pCIP (AIB1/ACTR/RAC-3/TRAM-1/SRC-3) and p300 to a RARE did correlate with RA-associated transcription of target mRNAs. Therefore, the specific functions of the RAR isotypes do not manifest at the level of their DNA binding but rather from a differential ability to recruit specific components of the transcriptional machinery. We also demonstrated that RA-mediated displacement of the polycomb group protein SUZ12 from a RARE was inhibited in the absence of RARgamma. Thus, transcriptional components of the RAR signaling pathway are specifically required for displacement of SUZ12 from RAREs during RA-mediated differentiation of F9 cells.
Gillespie
Robert F
RF
Molecular Biology Program, Weill Graduate School of Medical Sciences, Cornell University.
Gudas
Lorraine J
LJ
Molecular Biology Program, Weill Graduate School of Medical Sciences, Cornell University; Pharmacology Department, Weill Medical College of Cornell University, New York, New York 10021. Electronic address: ljgudas@med.cornell.edu.
D000818:Animals; D019556:COS Cells; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002522:Chlorocebus aethiops; D003577:Cytochrome P-450 Enzyme System / Q000378:metabolism; D015972:Gene Expression Regulation, Neoplastic; D051379:Mice; D008954:Models, Biological; D063151:Polycomb Repressive Complex 2; D020033:Protein Isoforms; D018168:Receptors, Retinoic Acid / Q000737:chemistry* / Q000502:physiology; D012097:Repressor Proteins / Q000378:metabolism; D020218:Response Elements; D000072516:Retinoic Acid 4-Hydroxylase; D000072482:Retinoic Acid Receptor alpha; D013234:Stem Cells / Q000378:metabolism*; D018243:Teratocarcinoma / Q000378:metabolism*; D014158:Transcription, Genetic
D020033:Protein Isoforms; C000607072:Rara protein, mouse; D018168:Receptors, Retinoic Acid; D012097:Repressor Proteins; D000072482:Retinoic Acid Receptor alpha; C494163:Suz12 protein, mouse; D003577:Cytochrome P-450 Enzyme System; C000607080:Cyp26a1 protein, mouse; D000072516:Retinoic Acid 4-Hydroxylase; D063151:Polycomb Repressive Complex 2