p53 is cleaved by caspases generating fragments localizing to mitochondria

Sayan, BS; Sayan, AE; Knight, RA; Melino, G; Cohen, GM

Abstract

The p53 tumor suppressor protein exerts most of its anti-tumorigenic activity by transcriptionally activating several pro-apoptotic genes. Accumulating evidence also suggests a transcription-independent function of p53 during apoptosis. It has recently been shown that, when activated, a fraction of p53 translocates to mitochondria, causing cytochrome c release. We now demonstrate a caspase-dependent cleavage of p53 resulting in the generation of four fragments, two of which lack a nuclear localization signal and consequently localize to cytosol. Moreover, these two fragments translocate to mitochondria and induce mitochondrial membrane depolarization in the absence of transcriptional activity. This novel feature of p53 supports the model whereby cytosolic p53 exerts major functions in apoptosis and also suggests the presence of a positive feedback loop in which activated caspases cleave p53 to augment mitochondrial membrane depolarization.

Citation

Sayan, B., Sayan, A., Knight, R., Melino, G., & Cohen, G. (2006). p53 is cleaved by caspases generating fragments localizing to mitochondria. Journal of Biological Chemistry, 281(19), 13566-13573. https://doi.org/10.1074/jbc.M512467200

• Journal Article Type: Article
• Publication Date: May 1, 2006
• Deposit Date: Feb 6, 2023
• Publicly Available Date: Feb 6, 2023
• Journal: Journal of Biological Chemistry
• Print ISSN: 0021-9258
• Electronic ISSN: 1083-351X
• Publisher: American Society for Biochemistry and Molecular Biology
• Volume: 281
• Issue: 19
• Pages: 13566-13573
• DOI: https://doi.org/10.1074/jbc.M512467200
• Publisher URL: https://doi.org/10.1074/jbc.M512467200