Title | Retinoic acid receptor isotype specificity in F9 teratocarcinoma stem cells results from the differential recruitment of coregulators to retinoic response elements. |
Publication Type | Journal Article |
Year of Publication | 2007 |
Authors | Gillespie RF, Gudas LJ |
Journal | J Biol Chem |
Volume | 282 |
Issue | 46 |
Pagination | 33421-34 |
Date Published | 2007 Nov 16 |
ISSN | 0021-9258 |
Keywords | Animals, Cell Differentiation, Cell Line, Tumor, Chlorocebus aethiops, COS Cells, Cytochrome P-450 Enzyme System, Gene Expression Regulation, Neoplastic, Mice, Models, Biological, Polycomb Repressive Complex 2, Protein Isoforms, Receptors, Retinoic Acid, Repressor Proteins, Response Elements, Retinoic Acid 4-Hydroxylase, Retinoic Acid Receptor alpha, Stem Cells, Teratocarcinoma, Transcription, Genetic |
Abstract | 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. |
DOI | 10.1074/jbc.M704845200 |
Alternate Journal | J. Biol. Chem. |
PubMed ID | 17875646 |
Grant List | R01CA043796 / CA / NCI NIH HHS / United States R01DK454560 / DK / NIDDK NIH HHS / United States |