Translational Control Protein 80 Stimulates IRES-Mediated Translation of p53 mRNA in Response to DNA Damage

Figure 2

TCP80 dsRBMs are important for the induction of the p53 IRES activity. (a) Map of TCP80/NF90 functional domains. TCP80 contains three RNA binding sites: the RGG domain and two dsRBMs. The mutated residues in the mdsRBM1 and mdsRBM2 constructs, respectively, are also shown in this diagram. (b) Effect of deletion of the RGG domain and the dsRBMs on TCP80-mediated p53 IRES induction. MCF-7 cells were transfected with pR5UTRF along with wild-type TCP80, TCP80Δ640-702 (minus RGG domain), or TCP80Δ401-702 (minus RGG and dsRBMs). Twenty-four hours after transfection, cells were lysed, and a dual-luciferase assay was performed. (c) Effect of mutations in the dsRBMs on TCP80-mediated p53 IRES induction. MCF-7 cells were transfected with pR5UTRF along with plasmids encoding wild-type TCP80, mutant dsRBM1 TCP80 (mdsRBM1), or mutant dsRBM2 TCP80 (mdsRBM2). Firefly and renilla luciferase activities were determined. The results presented in both (b) and (c) are average ± SEM from three individual experiments.

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