<p>(<b>A</b>) Electrophoretic gel mobility shift assays (EMSAs) of the mouse <i>Csn3</i> DR5 RARE. EMSA was performed following incubation of Alexa680-labeled, double-stranded <i>Csn3</i> DR5 RARE probe corresponding to −160/−131 of <i>Csn3</i> promoter (5′-ACTAAGACTGACCTGCAGGTGACCCTGGTG-3′) with nuclear extract from P19 cells that had been treated with ATRA for 3 h (lane 2) or with no added protein (lane 1). For competition assay, unlabeled homologous oligonucleotides were added in increasing amounts (5- or 20-fold excess) to the binding reactions; the unlabeled oligonucleotides functioned as competitors with the labeled probe (lane 3 and 4, respectively). NS represents the non-specific interactions. (<b>B</b>) EMSA for assaying RARα binding to <i>Csn3</i> DR5 RARE. Alexa680-labeled <i>Csn3</i> DR5 RARE probe was incubated with no added protein (lane 1) or with nuclear extract from P19 cells that had been treated with ATRA for 3 h (lane 2). Supershift assay was performed by addition of anti-RARα antibody (lane 3). The arrowhead indicates the supershifted band.</p
