Regulation of death receptor signaling by the autophagy protein TP53INP2.
EMBO J
; 38(10)2019 05 15.
Article
en En
| MEDLINE
| ID: mdl-30979779
ABSTRACT
TP53INP2 positively regulates autophagy by binding to Atg8 proteins. Here, we uncover a novel role of TP53INP2 in death-receptor signaling. TP53INP2 sensitizes cells to apoptosis induced by death receptor ligands. In keeping with this, TP53INP2 deficiency in cultured cells or mouse livers protects against death receptor-induced apoptosis. TP53INP2 binds caspase-8 and the ubiquitin ligase TRAF6, thereby promoting the ubiquitination and activation of caspase-8 by TRAF6. We have defined a TRAF6-interacting motif (TIM) and a ubiquitin-interacting motif in TP53INP2, enabling it to function as a scaffold bridging already ubiquitinated caspase-8 to TRAF6 for further polyubiquitination of caspase-8. Mutations of key TIM residues in TP53INP2 abrogate its interaction with TRAF6 and caspase-8, and subsequently reduce levels of death receptor-induced apoptosis. A screen of cancer cell lines showed that those with higher protein levels of TP53INP2 are more prone to TRAIL-induced apoptosis, making TP53INP2 a potential predictive marker of cancer cell responsiveness to TRAIL treatment. These findings uncover a novel mechanism for the regulation of caspase-8 ubiquitination and reveal TP53INP2 as an important regulator of the death receptor pathway.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Autofagia
/
Proteínas Nucleares
Tipo de estudio:
Prognostic_studies
Límite:
Animals
/
Humans
Idioma:
En
Revista:
EMBO J
Año:
2019
Tipo del documento:
Article