Cytochrome c activation of CPP32‐like proteolysis plays a critical role in a Xenopus cell‐free apoptosis system

摘要: In a cell-free system based on Xenopus egg extracts, Bcl-2 blocks apoptotic activity by preventing cytochrome c release from mitochondria. We now describe in detail the crucial role of this system. The mitochondrial fraction, when incubated with cytosol, releases c. Cytochrome turn induces activation protease(s) resembling caspase-3 (CPP32), leading to downstream events, including cleavage fodrin and lamin B1. CPP32-like protease plays an essential system, as caspase inhibitor, Ac-DEVD-CHO, strongly inhibited B1 cleavage, well nuclear morphology changes. preparations various vertebrate species, but not Saccharomyces cerevisiae, were able initiate all signs apoptosis. itself was unable process precursor form CPP32; presence cytosol required. electron transport is required for its pro-apoptotic function, Cu- Zn-substituted had strong activity, despite being redox-inactive. However, certain structural features molecule activity. Thus, cytosol-dependent apoptosis activating caspases, via unknown cytosolic factors.