What is the role of caspases in apoptosis?

Caspases are enzymes that play a crucial role in initiating and executing apoptosis, or programmed cell death.

Apoptosis is a highly regulated process that occurs in cells to maintain tissue homeostasis, eliminate damaged or infected cells, and prevent the development of cancer. Caspases are a family of proteases that are activated in response to various stimuli, such as DNA damage, oxidative stress, or cytokine signalling. They are responsible for cleaving and activating downstream effector proteins that ultimately lead to the dismantling of the cell.

There are two types of caspases: initiator caspases and effector caspases. Initiator caspases, such as caspase-8 and caspase-9, are activated by extracellular or intracellular signals and subsequently activate effector caspases, such as caspase-3 and caspase-7. Effector caspases cleave a variety of cellular substrates, including cytoskeletal proteins, DNA repair enzymes, and nuclear lamins, leading to the characteristic morphological changes observed in apoptotic cells, such as cell shrinkage, chromatin condensation, and membrane blebbing.

Caspases are tightly regulated by a variety of mechanisms, including post-translational modifications, protein-protein interactions, and subcellular localization. Dysregulation of caspase activity can lead to a variety of diseases, such as cancer, neurodegeneration, and autoimmune disorders.

In summary, caspases are essential enzymes that play a critical role in the regulation of apoptosis. Their activation and regulation are tightly controlled to ensure proper cellular function and prevent the development of disease.