Tag: Apoptosis

Post-translational modifications are essential regulators of apoptosis. Learn how phosphorylation, ubiquitination, acetylation, SUMOylation, methylation, and other PTMs control p53, BCL-2 proteins, caspases, mitochondrial apoptosis, and cell survival.

Apoptosis is a controlled form of programmed cell death that removes damaged or unnecessary cells without causing inflammation. Through coordinated activation of extrinsic and intrinsic pathways, apoptosis maintains tissue homeostasis and protects organisms from disease.

Programmed cell death (PCD) is a regulated biological process that eliminates damaged or unnecessary cells through apoptosis, autophagic cell death and regulated necrosis. By maintaining tissue homeostasis and supporting stress adaptation, PCD is essential for development and long‑term organismal health.

RIPK1 is a central signalling kinase that determines whether a cell survives, undergoes apoptosis or triggers necroptosis. Through context‑dependent interactions with TNFR1, caspase‑8, RIPK3 and MLKL, RIPK1 integrates inflammatory cues and stress signals to regulate cell fate.

The IAP family consists of intracellular proteins that regulate apoptosis, ubiquitination and immune signalling. Through their BIR domains and RING ligase activity, IAPs control caspase inhibition, NF‑κB activation, inflammasome signalling and tumour cell survival, making them central players in cell biology and cancer research.

XIAP is the most potent endogenous inhibitor of caspases and a central regulator of apoptosis and immune signalling. Through its BIR domains and RING ubiquitin ligase activity, XIAP blocks caspase‑3, caspase‑7 and caspase‑9 while modulating NF‑κB pathways, making it a key player in cancer, inflammation and immune disorders.

Survivin (BIRC5) is a tumour‑specific IAP that integrates apoptosis suppression with essential mitotic functions. As part of the chromosomal passenger complex, Survivin ensures proper chromosome segregation while stabilising anti‑apoptotic pathways, making it a central driver of tumour progression and therapy resistance.

Livin (ML‑IAP) is a tumour‑specific inhibitor of apoptosis that blocks caspase activity and ubiquitinates pro‑apoptotic proteins. Its splice variants, Livin‑α and Livin‑β, differ in potency, and its unique ability to switch from anti‑apoptotic to pro‑apoptotic after cleavage makes Livin a key regulator of tumour survival and therapy resistance.

cIAP2 is a ubiquitin ligase that regulates TNF receptor signalling, non‑canonical NF‑κB activation and NOD2‑mediated immune responses. By controlling RIPK1, RIPK2 and NIK stability, cIAP2 determines whether cells activate survival pathways or transition into apoptosis, making it essential in inflammation and cancer biology.

cIAP1 is a ubiquitin ligase that regulates TNF receptor signalling and determines whether cells activate NF‑κB survival pathways or switch into apoptosis or necroptosis. By controlling RIPK1 ubiquitination and cooperating with TRAF2, cIAP1 plays essential roles in inflammation, immunity and cancer biology.