Pre-processed caspase-9 contained in mitochondria participates in apoptosis.
Cell Death Differ
; 9(1): 82-8, 2002 Jan.
Article
en En
| MEDLINE
| ID: mdl-11803376
ABSTRACT
As shown here, mitochondria purified from different organs (liver, brain, kidney, spleen and heart) contain both pro-caspase-9 and the processed, mature form of caspase-9. Purified liver mitochondria release mature caspase-9 upon induction of permeability transition in vitro. This is accompanied by a discrete increase in the enzymatic cleavage of pro-caspase-9 substrates. We found that SHEP neuroblastoma cells constitutively contain pre-processed caspase-9 in their mitochondria, using a combination of subcellular fractionation and immunofluorescence with an antibody specific for the processed caspase. This is a cell type-specific phenomenon since HeLa cells mitochondria mainly contain pro-caspase-9 and comparatively little processed caspase-9. Upon introduction of apoptosis, mitochondrial pro-caspase-9 translocates to the cytosol and to the nucleus. This phenomenon is inhibited by transfection with Bcl-2. In synthesis, we report the unexpected finding that mitochondria can contain a pre-processed caspase isoform in non-apoptotic cells. Bcl-2-mediated regulation of mitochondrial membrane permeabilization may contribute to apoptosis control by preventing mitochondrial, pre-processed caspase-9 from interacting with its cytosolic activators.
Buscar en Google
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Apoptosis
/
Caspasas
/
Mitocondrias
Límite:
Humans
Idioma:
En
Revista:
Cell Death Differ
Año:
2002
Tipo del documento:
Article
País de afiliación:
Francia