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Bax and Bak can localize to the endoplasmic reticulum to initiate apoptosis

Authors :
Junying Yuan
Tullia Lindsten
Chi Li
Qian-Chun Yu
Craig B. Thompson
Wei-Xing Zong
Georgia Hatzivassiliou
Source :
The Journal of Cell Biology
Publication Year :
2003
Publisher :
The Rockefeller University Press, 2003.

Abstract

Bax and Bak play a redundant but essential role in apoptosis initiated by the mitochondrial release of apoptogenic factors. In addition to their presence at the mitochondrial outer membrane, Bax and Bak can also localize to the ER. Agents that initiate ER stress responses can induce conformational changes and oligomerization of Bax on the ER as well as on mitochondria. In wild-type cells, this is associated with caspase 12 cleavage that is abolished in bax−/−bak−/− cells. In bax−/−bak−/− cells, introduction of Bak mutants selectively targeted to either mitochondria or the ER can induce apoptosis. However, ER-targeted, but not mitochondria-targeted, Bak leads to progressive depletion of ER Ca2+ and induces caspase 12 cleavage. In contrast, mitochondria-targeted Bak leads to enhanced caspase 7 and PARP cleavage in comparison with the ER-targeted Bak. These findings demonstrate that in addition to their functions at mitochondria, Bax and Bak also localize to the ER and function to initiate a parallel pathway of caspase activation and apoptosis.

Details

Language :
English
ISSN :
15408140 and 00219525
Volume :
162
Issue :
1
Database :
OpenAIRE
Journal :
The Journal of Cell Biology
Accession number :
edsair.doi.dedup.....d1cddcbc42097acc60d86ab93047d0a0