What enzymes are primarily responsible for executing apoptosis?

The primary enzymes responsible for executing apoptosis are caspase enzymes. Caspases, or cysteine-aspartic proteases, play a crucial role in the apoptotic process by cleaving specific substrates within the cell, leading to the systematic dismantling of cellular components.

During apoptosis, these enzymes are initially synthesized as inactive precursors known as procaspases. Upon receiving apoptotic signals, procaspases are activated through a cascade of proteolytic cleavages, either via intrinsic pathways (mediated by mitochondrial signals) or extrinsic pathways (mediated by death receptors). Once activated, caspases execute apoptosis by targeted cleavage of key proteins, including structural proteins and enzymes involved in DNA repair and cell survival. This results in typical features of apoptosis, such as cell shrinkage, chromatin condensation, and the formation of apoptotic bodies that can be phagocytosed by neighboring cells without triggering an inflammatory response.

While other enzymes listed, such as proteases, kinases, and lipases, are involved in various cellular processes, they do not specifically execute apoptosis in the same targeted and regulated manner as caspases. For instance, proteases are a broad class of enzymes that break down proteins, but they do not have the