FIGURE 3.

In vivo, SUG-1 is co-recruited with SRC-3 to the promoter of RARα target genes. A, schematic representation of the promoter regions of the Cyp26A1 gene with the primer pairs used for their amplification. B and C, kinetic ChIP experiments performed with RA-treated MCF7 cells and determining the recruitment of RARα, SRC-3, and SUG-1 to the R1 and R2 regions. Values are expressed as -fold enrichment relative to untreated cells and correspond to a representative experiment among 3. D and E, Re-ChIP experiments performed with the indicated antibodies, showing that, at 60 min following RA addition, DNA-bound SRC-3 and RARα are associated with SUG-1. Values are expressed as -fold enrichment relative to control Re-ChIP experiments and are the mean ± S.D. of triplicate experiments. F, ChIP-Western experiments performed with MCF7 cells treated or not with RA for 60 min. The complexes immunoprecipitated with SRC-3 antibodies were analyzed by immunoblotting as indicated. Lane 1 corresponds to aliquots (10%) of unprecipitated extracts. G, kinetic ChIP experiments determining the recruitment of RARα, SRC-3, and SUG-1 to the RARβ2 promoter as in A. The promoter with the DR5 RARE is also shown.