Apoptin, a protein derived from the chicken anaemia virus, induces cell death in various cancer cells but shows little or no cytotoxicity in normal cells. The mechanism of apoptin-induced cell death is currently unknown but it appears to induce apoptosis independent of p53 status. Here we show that p73, a p53 family member, is important in apoptin-induced apoptosis. In p53 deficient and/or mutated cells, apoptin induced the expression of TAp73 leading to the induction of apoptosis. Knockdown of p73 using siRNA resulted in a significant reduction in apoptin-induced cytotoxicity. The p53 and p73 pro-apoptotic target PUMA plays an important role in apoptin-induced cell death as knockdown of PUMA significantly reduced cell sensitivity to apoptin. Importantly, apoptin expression resulted in a marked increase in TAp73 protein stability. Investigation into the mechanisms of TAp73 stability showed that apoptin induced the expression of the ring finger domain ubiquitin ligase PIR2 which is involved in the degradation of the anti-apoptotic ∆Np73 isoform. Collectively, our results suggest a novel mechanism of apoptin-induced apoptosis through increased TAp73 stability and induction of PIR2 resulting in the degradation of ∆Np73 and activation of pro-apoptotic targets such as PUMA causing cancer cell death.

Taebunpakul, P., Sayan, B., Flinterman, M., Klanrit, P., Gäken, J., Odell, E., et al. (2012). Apoptin induces apoptosis by changing the equilibrium between the stability of TAp73 and ΔNp73 isoforms through ubiquitin ligase PIR2. APOPTOSIS, 17(8), 762-776 [10.1007/s10495-012-0720-7].

Apoptin induces apoptosis by changing the equilibrium between the stability of TAp73 and ΔNp73 isoforms through ubiquitin ligase PIR2

MELINO, GENNARO;
2012-08-01

Abstract

Apoptin, a protein derived from the chicken anaemia virus, induces cell death in various cancer cells but shows little or no cytotoxicity in normal cells. The mechanism of apoptin-induced cell death is currently unknown but it appears to induce apoptosis independent of p53 status. Here we show that p73, a p53 family member, is important in apoptin-induced apoptosis. In p53 deficient and/or mutated cells, apoptin induced the expression of TAp73 leading to the induction of apoptosis. Knockdown of p73 using siRNA resulted in a significant reduction in apoptin-induced cytotoxicity. The p53 and p73 pro-apoptotic target PUMA plays an important role in apoptin-induced cell death as knockdown of PUMA significantly reduced cell sensitivity to apoptin. Importantly, apoptin expression resulted in a marked increase in TAp73 protein stability. Investigation into the mechanisms of TAp73 stability showed that apoptin induced the expression of the ring finger domain ubiquitin ligase PIR2 which is involved in the degradation of the anti-apoptotic ∆Np73 isoform. Collectively, our results suggest a novel mechanism of apoptin-induced apoptosis through increased TAp73 stability and induction of PIR2 resulting in the degradation of ∆Np73 and activation of pro-apoptotic targets such as PUMA causing cancer cell death.
ago-2012
Pubblicato
Rilevanza internazionale
Articolo
Esperti anonimi
Settore BIO/11 - BIOLOGIA MOLECOLARE
English
Proteolysis; Ubiquitin-Protein Ligases; Tumor Suppressor Protein p53; Apoptosis; Capsid Proteins; G2 Phase Cell Cycle Checkpoints; DNA-Binding Proteins; Humans; Protein Stability; Protein Processing, Post-Translational; Apoptosis Regulatory Proteins; Cell Line, Tumor; Protein Isoforms; Tumor Suppressor Proteins; Proto-Oncogene Proteins; Half-Life; Nuclear Proteins; Poly(ADP-ribose) Polymerases; Ubiquitination
Taebunpakul, P., Sayan, B., Flinterman, M., Klanrit, P., Gäken, J., Odell, E., et al. (2012). Apoptin induces apoptosis by changing the equilibrium between the stability of TAp73 and ΔNp73 isoforms through ubiquitin ligase PIR2. APOPTOSIS, 17(8), 762-776 [10.1007/s10495-012-0720-7].
Taebunpakul, P; Sayan, B; Flinterman, M; Klanrit, P; Gäken, J; Odell, E; Melino, G; Tavassoli, M
Articolo su rivista
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2108/78437
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