Chapter_18_Apoptosis

Apoptosis

A programmed cell death mechanism for removing unnecessary, damaged, or infected cells.

Necrosis

Unregulated cell death resulting from damage or stress, typically leading to inflammation.

Caspases

Family of cysteine proteases involved in the process of apoptosis.

Phosphatidylserine

A phospholipid that flips to the outer leaflet of the cell membrane during apoptosis, signaling for phagocytosis.

Blebbing

The protrusion of cytoplasm from the cell surface during apoptosis.

Pyknosis

Nuclear condensation that occurs during apoptosis.

Initiator Caspases

Caspases that activate other caspases as part of the apoptotic signaling process.

Effector Caspases

Caspases that cleave various cellular proteins to execute apoptosis.

Death Receptors

Proteins on the cell surface that activate apoptotic signaling pathways upon ligand binding.

Death Inducing Signaling Complex (DISC)

A complex formed by the aggregation of death receptors and adaptor proteins, leading to the activation of initiator caspases.

Mitochondrial outer membrane permeabilization (MOMP)

A key event in the intrinsic apoptotic pathway that leads to the release of cytochrome C.

Cytochrome C

A mitochondrial protein released into the cytosol during apoptosis, facilitating apoptosome formation.

Apoptosome

A large protein complex formed in the cytosol that activates caspase-9 during the intrinsic pathway of apoptosis.

Bcl proteins

A family of proteins that regulate apoptosis through pro-apoptotic and anti-apoptotic functions.

Pro-apoptotic Bcl proteins

Proteins that promote apoptosis, such as Bak and Bax.

Anti-apoptotic Bcl proteins

Proteins that inhibit apoptosis by maintaining mitochondrial integrity, such as Bcl-2.

Inhibitors of Apoptosis (IAPs)

Proteins that inhibit caspase function to prevent apoptosis.

BH domains

Bcl-2 homology domains that characterize Bcl proteins and their apoptotic functions.

Smac and Omi

Mitochondrial proteins in mammals that promote apoptosis by disrupting IAPs.

Tumor Necrosis Factor (TNF) receptor family

A group of cell surface receptors that trigger apoptosis when activated by ligands.

Caspase 8

An initiator caspase activated in the DISC that initiates the extrinsic pathway of apoptosis.

CAD (Caspase Activated DNase)

An endonuclease released during apoptosis that cleaves DNA.

Polyubiquitination

A process involved in marking proteins for degradation by the proteasome.

PI3K/AKT pathway

A signaling pathway important for cell survival and inhibiting apoptosis.

Akt kinase

An enzyme that promotes cell survival by phosphorylating and inactivating pro-apoptotic proteins like Bad.

Bad

A pro-apoptotic protein that normally promotes apoptosis when not phosphorylated by Akt.

FADD

An adaptor protein that recruits initiator caspases in the extrinsic apoptosis pathway.

Intrinsic pathway

An apoptotic pathway triggered by internal signals, primarily involving mitochondrial dysfunction.

Extrinsic pathway

An apoptotic pathway activated by external signals via death receptors.

Caspase recruitment domain (CARD)

A domain within initiator caspases that facilitates their activation.

Death domain (DD)

A protein domain that is involved in the signaling mechanisms of death receptors.

Caspase inactivation

The process of preventing caspase function, often to inhibit apoptosis.

Grim, Reaper & HID

Inhibitors of apoptosis in Drosophila that promote cell death.

IBM (IAP binding motif)

A sequence that allows pro-apoptotic proteins to bind and inhibit IAPs.

Nuclear membrane disintegration

The breakdown of the nuclear membrane, a consequence of apoptotic signaling.

DNA Fragmentation

The breaking up of DNA into smaller pieces, a hallmark of apoptosis.

Golgi fragmentation

The breakdown of the Golgi apparatus during the apoptotic process.

Phospholipids phosphorylation

A modification that promotes signaling pathways like PI3K for cell survival.

Signal to phagocytosis

Indicates that the cell is undergoing apoptosis and should be engulfed by macrophages.

Caspase activation

The process of converting procaspases into active caspases via proteolytic cleavage.

Survival factors

Signals that promote cell survival and inhibit apoptosis in cells.