Two internal ribosome entry sites mediate the translation of p53 isoforms.

ABSTRACT: The p53 tumour suppressor protein has a crucial role in cell-cycle arrest and apoptosis. Previous reports show that the p53 messenger RNA is translated to produce an amino-terminal-deleted isoform (DeltaN-p53) from an internal initiation codon, which acts as a dominant-negative inhibitor of full-length p53. Here, we show that two internal ribosome entry sites (IRESs) mediate the translation of both full-length and DeltaN-p53 isoforms. The IRES directing the translation of full-length p53 is in the 5'-untranslated region of the mRNA, whereas the IRES mediating the translation of DeltaN-p53 extends into the protein-coding region. The two IRESs show distinct cell-cycle phase-dependent activity, with the IRES for full-length p53 being active at the G2-M transition and the IRES for DeltaN-p53 s

SUBMITTER: Ray PS 

PROVIDER: S-EPMC1456917 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature