Apoptosis Initiated When BH3 Ligands Engage Multiple Bcl-2 Homologs, Not Bax or Bak
Abstract
A central issue in the regulation of apoptosis by the Bcl-2 family is whether its BH3-only members initiate apoptosis by directly binding to the essential cell-death mediators Bax and Bak, or whether they can act indirectly, by engaging their pro-survival Bcl-2-like relatives. Contrary to the direct-activation model, we show that Bax and Bak can mediate apoptosis without discernable association with the putative BH3-only activators (Bim, Bid, and Puma), even in cells with no Bim or Bid and reduced Puma. Our results indicate that BH3-only proteins induce apoptosis at least primarily by engaging the multiple pro-survival relatives guarding Bax and Bak.
- Publication:
-
Science
- Pub Date:
- February 2007
- DOI:
- 10.1126/science.1133289
- Bibcode:
- 2007Sci...315..856W
- Keywords:
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- CELL BIOL