FIGURE 3.

Region spanning amino acids 96–173 of MEF2C is involved in the binding of Pin1. A, schematic representation of the deletion mutants of FLAG-MEF2C used to identify the binding sites of Pin1. The light boxes indicate the FLAG tag (F) and the following functional domains: MADS (DNA binding domain), MEF2 (dimerization domain), transcriptional activation domains 1 and 2 (TAD1 and TAD2, respectively), and nuclear localization signal (NLS). The numbers reported indicate the positions of the amino acid residues of MEF2C. B and C, total extracts of COS1 cells expressing the full-length FLAG-MEF2C (WT) or its deletion mutants were subjected to GST and GST-Pin1 pull-down followed by Western blot with anti-FLAG antibody. D, amino acid sequence of the region of MEF2C spanning the residues 96–173. Serines 98 and 110 are shown in boldface type and shaded; they represent the only serine-proline motifs in this region.