Mitochondrial apoptosis induced by BH3-only molecules in the exclusive presence of endoplasmic reticular Bak.

ABSTRACT: Bak and Bax are critical apoptotic mediators that naturally localize to both mitochondria and the endoplasmic reticulum (ER). Although it is generally accepted that mitochondrial expression of Bak or Bax suffices for apoptosis initiated by BH3-only homologues, it is currently unclear whether their reticular counterparts may have a similar potential. In this study, we show that cells exclusively expressing Bak in endoplasmic membranes undergo cytochrome c mobilization and mitochondrial apoptosis in response to BimEL and Puma, even when these BH3-only molecules are also targeted to the ER. Surprisingly, calcium was necessary but not sufficient to drive the pathway, despite normal ER calcium levels. We provide evidence that calcium functions coordinately with the ER-stress surveillance machin

SUBMITTER: Klee M 

PROVIDER: S-EPMC2699367 | biostudies-literature | 2009 Jun

REPOSITORIES: biostudies-literature