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Cell Death
Metazoans
Intrinsic Apoptosis (Mitochondrial)
Cell death triggered by internal stress via mitochondrial cytochrome c release.
Overview
The intrinsic pathway is initiated by cellular stresses. Pro-apoptotic BCL-2 family members (BAX, BAK) oligomerize in the outer mitochondrial membrane, releasing cytochrome c. Cytochrome c binds APAF-1 to form the apoptosome, activating caspase-9 and triggering the caspase cascade.
Cellular Location
Mitochondria → cytoplasm
Clinical Significance
Major tumor suppressive mechanism; venetoclax targets BCL-2 in CLL; resistance to apoptosis is a hallmark of cancer.
Key Molecules
Key Enzymes
Related Pathways
Extrinsic Apoptosis (Death Receptor)
Cell death initiated by death ligand-receptor interactions at the cell surface.
Cell Cycle Checkpoints
Surveillance mechanisms ensuring genomic integrity at each cell cycle phase.
PI3K/AKT/mTOR Pathway
Regulates cell survival, growth, and metabolism via phosphoinositide signaling.