Apoptosis is carried out by proteases known as _____, which cleave targets at _____ _____ residues.

Apoptosis, or programmed cell death, is a vital process in maintaining cellular homeostasis and development. One of the key players in apoptosis is a specific class of proteases known as caspases. These enzymes are instrumental in executing the apoptotic signal by cleaving key cellular proteins.

Caspases are characterized by their unique substrate specificity, which involves the cleavage at aspartic acid residues. This specificity is critical for their function in promoting apoptosis, as it ensures that only certain target proteins are processed, leading to the systematic dismantling of the cell. When this cleavage occurs, it initiates a cascade of events that result in characteristic morphological changes associated with apoptosis, such as cell shrinkage, chromatin condensation, and ultimately, cellular fragmentation.

This critical function of caspases in targeting aspartic acid residues distinguishes them from other types of proteases that may cleave at different amino acids or have broader substrate specificity. This specificity for aspartic acid is not just a trivial detail; it is a defining feature that plays a fundamental role in how these enzymes facilitate the orderly and controlled process of programmed cell death.