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Mitochondrial BCL‐2 inhibits AMBRA1‐induced autophagy
Author(s) -
Strappazzon Flavie,
VietriRudan Matteo,
Campello Silvia,
Nazio Francesca,
Florenzano Fulvio,
Fimia Gian Maria,
Piacentini Mauro,
Levine Beth,
Cecconi Francesco
Publication year - 2011
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1038/emboj.2011.49
Subject(s) - autophagy , biology , microbiology and biotechnology , apoptosis , endoplasmic reticulum , mitochondrion , programmed cell death , biochemistry
BECLIN 1 is a central player in macroautophagy. AMBRA1, a BECLIN 1‐interacting protein, positively regulates the BECLIN 1‐dependent programme of autophagy. In this study, we show that AMBRA1 binds preferentially the mitochondrial pool of the antiapoptotic factor BCL‐2, and that this interaction is disrupted following autophagy induction. Further, AMBRA1 can compete with both mitochondrial and endoplasmic reticulum‐resident BCL‐2 (mito‐BCL‐2 and ER‐BCL‐2, respectively) to bind BECLIN 1. Moreover, after autophagy induction, AMBRA1 is recruited to BECLIN 1. Altogether, these results indicate that, in normal conditions, a pool of AMBRA1 binds preferentially mito‐BCL‐2; after autophagy induction, AMBRA1 is released from BCL‐2, consistent with its ability to promote BECLIN 1 activity. In addition, we found that the binding between AMBRA1 and mito‐BCL‐2 is reduced during apoptosis. Thus, a dynamic interaction exists between AMBRA1 and BCL‐2 at the mitochondria that could regulate both BECLIN 1‐dependent autophagy and apoptosis.