TY - JOUR
T1 - Tumor Necrosis Factor-α Induces Bax-Bak Interaction and Apoptosis, Which Is Inhibited by Adenovirus E1B 19K
AU - Sundararajan, Ramya
AU - Cuconati, Andrea
AU - Nelson, Deirdre
AU - White, Eileen
PY - 2001/11/30
Y1 - 2001/11/30
N2 - Tumor necrosis factor (TNF)-α-mediated death signaling induces oligomerization of proapoptotic Bcl-2 family member Bax into a high molecular mass protein complex in mitochondrial membranes. Bax complex formation is associated with the release of cytochrome c, which propagates death signaling by acting as a cofactor for caspase-9 activation. The adenovirus Bcl-2 homologue E1B 19K blocks TNF-α-mediated apoptosis by preventing cytochrome c release, caspase-9 activation, and apoptosis of virus-infected cells. TNF-α induces E1B 19K-Bax interaction and inhibits Bax oligomerization. Oligomerized Bax may form a pore to release mitochondrial proteins, analogous to the homologous pore-forming domains of bacterial toxins. E1B 19K can also bind to proapoptotic Bak, but the functional significance is not known. TNF-α signaling induced Bak-Bax interaction and both Bak and Bax oligomerization. E1B 19K was constitutively in a complex with Bak, and blocked the Bak-Bax interaction and oligomerization of both. The TNF-α-mediated cytochrome c and Smac/DIABLO release from mitochondria was inhibited by E1B 19K expression in adenovirus-infected cells. Since either Bax or Bak is essential for death signaling by TNF-α, the interaction between E1B 19K and both Bak and Bax may be required to inhibit their cooperative or independent oligomerization to release proteins from mitochondria which promote caspase activation and cell death.
AB - Tumor necrosis factor (TNF)-α-mediated death signaling induces oligomerization of proapoptotic Bcl-2 family member Bax into a high molecular mass protein complex in mitochondrial membranes. Bax complex formation is associated with the release of cytochrome c, which propagates death signaling by acting as a cofactor for caspase-9 activation. The adenovirus Bcl-2 homologue E1B 19K blocks TNF-α-mediated apoptosis by preventing cytochrome c release, caspase-9 activation, and apoptosis of virus-infected cells. TNF-α induces E1B 19K-Bax interaction and inhibits Bax oligomerization. Oligomerized Bax may form a pore to release mitochondrial proteins, analogous to the homologous pore-forming domains of bacterial toxins. E1B 19K can also bind to proapoptotic Bak, but the functional significance is not known. TNF-α signaling induced Bak-Bax interaction and both Bak and Bax oligomerization. E1B 19K was constitutively in a complex with Bak, and blocked the Bak-Bax interaction and oligomerization of both. The TNF-α-mediated cytochrome c and Smac/DIABLO release from mitochondria was inhibited by E1B 19K expression in adenovirus-infected cells. Since either Bax or Bak is essential for death signaling by TNF-α, the interaction between E1B 19K and both Bak and Bax may be required to inhibit their cooperative or independent oligomerization to release proteins from mitochondria which promote caspase activation and cell death.
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U2 - 10.1074/jbc.M106386200
DO - 10.1074/jbc.M106386200
M3 - Article
C2 - 11571294
SN - 0021-9258
VL - 276
SP - 45120
EP - 45127
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 48
ER -