Rizzotto Dario, Zaccara Sara, Rossi Annalisa, Galbraith Matthew D, Andrysik Zdenek, Pandey Ahwan, Sullivan Kelly D, Quattrone Alessandro, Espinosa Joaquín M, Dassi Erik, Inga Alberto
Department of Cellular, Computational and Integrative Biology (CIBIO), University of Trento, via Sommarive 9, 38123 Trento, Italy.
Linda Crnic Institute for Down Syndrome, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA; Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, Boulder, CO 80203, USA.
Cell Rep. 2020 Mar 31;30(13):4355-4369.e6. doi: 10.1016/j.celrep.2020.03.011.
Activation of p53 by the small molecule Nutlin can result in a combination of cell cycle arrest and apoptosis. The relative strength of these events is difficult to predict by classical gene expression analysis, leaving uncertainty as to the therapeutic benefits. In this study, we report a translational control mechanism shaping p53-dependent apoptosis. Using polysome profiling, we establish Nutlin-induced apoptosis to associate with the enhanced translation of mRNAs carrying multiple copies of an identified 3' UTR CG-rich motif mediating p53-dependent death (CGPD-motif). We identify PCBP2 and DHX30 as CGPD-motif interactors. We find that in cells undergoing persistent cell cycle arrest in response to Nutlin, CGPD-motif mRNAs are repressed by the PCBP2-dependent binding of DHX30 to the motif. Upon DHX30 depletion in these cells, the translation of CGPD-motif mRNAs increases, and the response to Nutlin shifts toward apoptosis. Instead, DHX30 inducible overexpression in SJSA1 cells leads to decreased translation of CGPD-motif mRNAs.
小分子Nutlin激活p53可导致细胞周期停滞和细胞凋亡。通过经典基因表达分析难以预测这些事件的相对强度，这使得治疗益处存在不确定性。在本研究中，我们报告了一种塑造p53依赖性细胞凋亡的翻译控制机制。利用多核糖体谱分析，我们确定Nutlin诱导的细胞凋亡与携带多个介导p53依赖性死亡的已鉴定3'UTR富含CG基序（CGPD基序）的mRNA的翻译增强有关。我们鉴定出PCBP2和DHX30为CGPD基序相互作用蛋白。我们发现，在因Nutlin而经历持续细胞周期停滞的细胞中，CGPD基序mRNA被DHX30通过PCBP2依赖性结合到该基序而抑制。在这些细胞中DHX30缺失后，CGPD基序mRNA的翻译增加，对Nutlin的反应转向细胞凋亡。相反，SJSA1细胞中DHX30的诱导性过表达导致CGPD基序mRNA的翻译减少。
