Caspase-9 plays a marginal role in serum starvation-induced apoptosis
| Autor: | Christa Cerni, Chantal J. Schamberger, Christopher Gerner |
|---|---|
| Rok vydání: | 2005 |
| Předmět: |
Apoptosis
Culture Media Serum-Free Cell Line Animals Humans APAF1 Growth Substances Cytoskeleton Caspase Inclusion Bodies Caspase-9 biology Cytochrome c Intrinsic apoptosis Cytochromes c Proteins Blood Proteins Cell Biology Apoptosome assembly Caspase 9 Mitochondria Rats Cell biology Apoptotic Protease-Activating Factor 1 Caspases biology.protein Keratins Apoptosome HeLa Cells Signal Transduction |
| Zdroj: | Experimental Cell Research. 302:115-128 |
| ISSN: | 0014-4827 |
| DOI: | 10.1016/j.yexcr.2004.08.026 |
| Popis: | Serum withdrawal represents a potent trigger to induce caspase-dependent apoptosis in a series of cell culture models. In rat 423-cells, caspase-8 and caspase-3 were apparently sufficient to initiate and proceed apoptosis without involving the intrinsic amplification loop via caspase-9. To assess the reasons for this inactivity of an otherwise crucial initiator caspase, we examined the ability for apoptosome assembly in 423-cells. Caspase-9 and Apaf-1 were expressed and cytochrome c released from mitochondria upon serum withdrawal. Although functional apoptosomes were assembled successfully in vitro, caspase-9 processing was found essentially refrained during apoptosis in 423-cells. Cell fractionation experiments revealed that sequestration of caspase-9 to cytoskeletal structures in 423-cells contributed to the observed impairment of apoptosome formation. Altogether, these findings provide evidence that serum starvation-induced apoptosis may occur independently of the intrinsic pathway and that caspase-9 sequestration potentially represents a novel biological antiapoptotic strategy. |
| Databáze: | OpenAIRE |
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