Ribonuclease activity of p53 in cytoplasm in response to various stress signals.

The tumor suppressor p53 protein is expressed at low levels under normal conditions. The subcellular localization and functional activation of p53 are influenced by diverse stress signals. p53 in cytoplasm exerts intrinsic 3'→5' exonuclease activity with various RNA and DNA substrates.

p53 in cytoplasm exerts 3'→5' exonuclease activity with dsRNA.

Double-stranded RNA (dsRNA) is a biologically active molecule that plays important roles in normal cell growth and function. Accordingly, the cell uses multiple mechanisms to control its level. The tumor suppressor protein p53 possesses intrinsic 3'→5' exonuclease activity.