Figure 3. PCBP1 directly binds to p63 3′UTR.

. (A) PCBP1 interacts with p63 transcripts in vivo. Cell lysates from HaCaT cells were collected and immunoprecipitated with PCBP1 antibody or control IgG, followed by RT-PCR analysis to determine the level of ΔNp63 transcripts in control IgG and anti-PCBP1 immunocomplexes. The levels of p21 and Actin transcripts were measured as positive and negative controls, respectively. (B) Schematic presentation of p63α transcript and the location of probes. CUE regions are shown in shaded box. (C) PCBP1 directly binds to p63 3′UTR. REMSA was performed by mixing a ³²P-labeled RNA probes (A, B, C, or p21 probe) with recombinant GST or GST-fused PCBP1. The arrow indicates RNA-protein complexes. (D) REMSA assay was performed by mixing a ³²P-labeled RNA probe A along with or without excess amount (50-fold) of unlabeled p21 or probe A.