This proteolytic cascade, in which one caspase can activate other caspases, amplifies the apoptotic signaling pathway and thus leads to rapid cell death. The term apoptosis was coined by kerr, wyllie and currie in 1972 to describe a mode of cell death associated with fragmentation of genomic dna kerr et al. This video will describe the initiator and effector caspases and the role they play during apoptosis. The extrinsic apoptosis pathway is activated through the binding of a. Synthesized in the cell as precursors named procaspase. Two major apoptotic pathways have been described, the intrinsic pathway involving initial mitochondrial perturbation resulting from cellular stress. There are a wide range of caspases which are involved in apoptosis processes. Among them, caspase3 is a frequently activated death protease, catalyzing the. Caspases caspases or cysteineaspartic proteases or cysteinedependent aspartatedirected proteases are a family of cysteine proteases that play essential roles in apoptosis programmed cell death, necrosis, and inflammation. Caspase role in apoptosis cut off contact with surrounding cells reorganize cytoskeleton shut don dna replication and repair interrupt. At least 14 different members of caspases in mammalian cells have. Programmed cell death and its clinical implications. Apoptosis is a biological mechanism which is one type of programmed cell death. Contains an nterminal domain, a small subunit and a large subunit similar to a ribosome.
Activation of caspases during apoptosis results in the cleavage of critical cellular substrates, including polyadpribose polymerase and. Caspases family of proteins main executors of the apoptotic. Inflammatory caspases do not function in apoptosis but are rather involved in inflammatory cytokine signaling and other types of cell death such as pyroptosis. Initiator caspases initiate the apoptosis signal while the executioner caspases carry out the mass proteolysis that leads to apoptosis. A free powerpoint ppt presentation displayed as a flash slide show on id.
Caspases are essential in cells for apoptosis, or programmed cell death. View p53 apoptosis ppts online, safely and virusfree. Caspases have the characteristics of high specificity for substrates containing asp, and use a cys for catalyzing peptide bond cleavage. Recent studies have suggested that the process of caspase activation differs for initiator caspases, which transduce various signals into protease activity, and. Deathinducing signaling complex and the death receptor pathway. Ordering of caspases in cells undergoing apoptosis by the intrinsic. Emerging roles of caspase3 in apoptosis cell death. Caspases are crucial mediators of programmed cell death apoptosis. Activation of caspase proteases initiates the death. Apoptosis programmed cell death apoptosis vs necrosis level of stress, change in environment modes of cell death a pathological response to injury chromatin. Scribd is the worlds largest social reading and publishing site.
In my own, presentation on apoptosis is descride in breif over view. This 3d medical animation explains the functioning of the extrinsic and intrinsic apoptotic pathways. The two pathways both activate initiator caspases, which then activate executioner caspases, which then. Mount sinai school of medicine department of pharmacology and biological chemistry cell signaling systems course spring 2005 a free powerpoint ppt presentation displayed as a flash slide show on id.