Bcl-xL does not inhibit the function of Apaf-1.
Cell Death Differ
; 7(4): 402-7, 2000 Apr.
Article
en En
| MEDLINE
| ID: mdl-10773825
ABSTRACT
Bcl-2 and its relative, Bcl-xL, inhibit apoptotic cell death primarily by controlling the activation of caspase proteases. Previous reports have suggested at least two distinct mechanisms Bcl-2 and Bcl-xL may inhibit either the formation of the cytochrome c/Apaf-1/caspase-9 apoptosome complex (by preventing cytochrome c release from mitochondria) or the function of this apoptosome (through a direct interaction of Bcl-2 or Bcl-xL with Apaf-1). To evaluate this latter possibility, we added recombinant Bcl-xL protein to cell-free apoptotic systems derived from Jurkat cells and Xenopus eggs. At low concentrations (50 nM), Bcl-xL was able to block the release of cytochrome c from mitochondria. However, although Bcl-xL did associate with Apaf-1, it was unable to inhibit caspase activation induced by the addition of cytochrome c, even at much higher concentrations (1-5 microM). These observations, together with previous results obtained with Bcl-2, argue that Bcl-xL and Bcl-2 cannot block the apoptosome-mediated activation of caspase-9.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Proteínas
/
Apoptosis
/
Proteínas Proto-Oncogénicas c-bcl-2
Límite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
Cell Death Differ
Año:
2000
Tipo del documento:
Article
País de afiliación:
Estados Unidos