Nuclear Pore Component Nup98 Is a Potential Tumor Suppressor and Regulates Posttranscriptional Expression of Select p53 Target Genes

SummaryThe p53 tumor suppressor utilizes multiple mechanisms to selectively regulate its myriad target genes, which in turn mediate diverse cellular processes. Here, using conventional and single-molecule mRNA analyses, we demonstrate that the nucleoporin Nup98 is required for full expression of p21, a key effector of the p53 pathway, but not several other p53 target genes. Nup98 regulates p21 mRNA levels by a posttranscriptional mechanism in which a complex containing Nup98 and the p21 mRNA 3′UTR protects p21 mRNA from degradation by the exosome. An in silico approach revealed another p53 target (14-3-3σ) to be similarly regulated by Nup98. The expression of Nup98 is reduced in murine and human hepatocellular carcinomas (HCCs) and correlates with p21 expression in HCC patients. Our study elucidates a previously unrecognized function of wild-type Nup98 in regulating select p53 target genes that is distinct from the well-characterized oncogenic properties of Nup98 fusion proteins.

Graphical AbstractFigure optionsDownload full-size imageDownload high-quality image (233 K)Download as PowerPoint slideHighlights► Nup98 is required for full induction of select p53 target genes such as p21 ► Nup98 associates with the 3′UTR of p21 mRNA preventing exosomal degradation ► Nup98 is downregulated in murine and human HCC and correlates with p21 expression