Caspase Regulation in Programmed Cell Death

Caspases are a family of cysteine–aspartic proteases that serve as central effectors and initiators of programmed cell death. Synthesised as inactive zymogens, they undergo tightly controlled activation through adaptor-mediated proximity, proteolytic processing and post-translational modifications. Initiator caspases, such as caspase-8 and caspase-9, respond to extracellular death-receptor signals or mitochondrial perturbations, respectively, and cleave downstream effector caspases (for example caspase-3 and caspase-7) to execute the apoptotic programme. Beyond apoptosis, caspases intersect with inflammatory circuits to drive pyroptosis, necroptosis and the emerging concept of PANoptosis. Regulatory layers such as alternative splicing, phosphorylation, ubiquitination and interactions with endogenous inhibitors finely tune caspase activity, subcellular localisation and substrate specificity. Dysregulation of these control points underpins a range of human disorders, from neurodegeneration and autoimmune disease to cancer, and has spurred interest in therapeutic strategies to selectively modulate caspase function.

Research from Nature Portfolio

Recent studies have demonstrated the power of optogenetic tools to dissect caspase-8 activation with precise temporal and spatial resolution. By fusing the photoreceptive PHR domain of Arabidopsis cryptochrome 2 to caspase-8 and pairing it with the light-interacting CIB1N protein, researchers devised two complementary systems to induce caspase-8 dimerisation and activation on exposure to blue light. The second strategy, which relies on independent fusions of caspase-8 to each photoreceptor, achieved markedly higher efficiency in triggering apoptosis in cultured human cells. This approach has provided unprecedented control over the initiation of the extrinsic apoptotic cascade, offering a versatile platform for screening modulators of caspase activity, mapping downstream signalling events and probing thresholds that distinguish survival from death.

Caspase Regulation in Programmed Cell Death publication trend

The graph below shows the total number of articles in caspase regulation in programmed cell death across all publications each year (not limited to Nature Index journals).

Technical terms

Caspase: Cysteine protease that cleaves substrates after aspartic acid residues to mediate cell death or inflammatory signalling.

Zymogen: Inactive enzyme precursor that requires proteolytic cleavage or induced proximity to become active.

Extrinsic apoptosis: Programmed cell death initiated by ligand binding to death receptors on the cell surface.

PANoptosis: Integrated cell death pathway encompassing features of pyroptosis, apoptosis and necroptosis.

Post-translational modification: Chemical alteration of a protein after synthesis, such as phosphorylation or ubiquitination, that regulates its activity and interactions.

References

1. Caspase-8 in inflammatory diseases: a potential therapeutic target. Cellular & Molecular Biology Letters (2024).
2. Targeting caspase-8: a new strategy for combating hepatocellular carcinoma. Frontiers in Immunology (2024).
3. Caspase-8: Arbitrating Life and Death in the Innate Immune System. Cells (2025).
4. Optogenetic induction of caspase-8 mediated apoptosis by employing Arabidopsis cryptochrome 2. Scientific Reports (2023).