Intrinsic apoptotic pathway proteins

Intrinsic apoptotic pathway proteins are a collective group of molecules that regulate and execute mitochondria-mediated apoptosis in response to cellular signals such as DNA damage, hypoxia, or oncogene activation. Key regulators include members of the Bcl-2 family (pro-apoptotic: BAX, BAK, BAD, BOK; anti-apoptotic: Bcl-2, Bcl-xL, Mcl-1), cytosolic proteins like Apaf-1, mitochondrial proteins such as cytochrome c, and executioner enzymes known as caspases (initiator caspase-9, effector caspase-3, caspase-7). Inhibitors of apoptosis (IAPs; e.g., XIAP, survivin) regulate caspase activity. The pathway is essential for normal development, tissue homeostasis, and elimination of damaged cells, with dysregulation linked to cancer, neurodegeneration, and other diseases. Individual proteins often serve as both biomarkers and therapeutic targets.

Other names

mitochondrial pathway of apoptosis proteinsintrinsic apoptosis proteinsmitochondrial apoptotic proteins

Bcl-2 inhibition increases mitochondrial permeability, triggers cytochrome c release; SMAC mimetics antagonize IAPs, allowing caspase activation; Caspase activation cleaves cellular substrates leading to apoptosis