Wrap53, a novel regulator of p53.

Natural antisense transcripts are a group of regulatory RNAs whose existence has been known for a long time but whose functional significance is still relatively unknown. Studies indicate that a large fraction of all mammalian genes may be regulated by antisense transcripts suggesting a central role of this regulation in eukaryotic gene expression. Wrap53 is a natural antisense transcript of p53 that regulates endogenous p53 mRNA levels and is furthermore required for induction of p53 protein by targeting the 5'untranslated region of p53 mRNA. Our discovery of Wrap53 demonstrates for the first time that an antisense transcript has an essential role in the regulation of p53 mRNA. This finding provides important new insight into p53 regulation and the mechanism of antisense-mediated gene regulation in human cells.