The Caspases The Executioners Biology essay
Abstract. Caspases, cysteine-aspartate-specific proteases, coordinate the cell dismantling that occurs during apoptosis and activate the membrane changes that cause recognition. Caspases belong to a family of highly conserved cysteine-dependent aspartate-specific acid proteases that use a cysteine residue as the catalytic nucleophile and share a stringent specificity for cleaving their substrates after aspartic acid residues in target proteins, Alnemri et al. 1996 A member of this family was identified first identified as. Caspases, the executioners of programmed cell death, are normally synthesized as inactive zymogens and are activated by proteolytic processing of their subunits. We show here, using two different caspases, Caenorhabditis elegans CED-human Caspase-3, that co-expression of the subunits constitutively generates activity. The executioners in both intrinsic and extrinsic pathways of cell death are the caspases, which are cysteine proteases with specificity to cleave their cell death. substrates after aspartic acid residues. The first member of the caspase family, caspase-1, was initially known as interleukin-1β-converting enzyme ICE, an enzyme required for tissue regeneration. Contrary to the long-held idea that apoptotic caspases are exclusively executioners of programmed cell death, an abundance of evidence is emerging that activation of caspases does not inevitably lead to apoptosis. initiators, while caspases are -3,6 executioner caspases. Behzadi and Caspases, a family of intracellular proteases considered to be the executioners of apoptosis, have been highlighted for their role in the development of the central nervous system, Yuan and Yankner, 2000. As cell death accelerators, they accurately indicate the size of cell populations in the brain. developing embryo again, also in the Summary. Caspases, cysteine-dependent aspartyl-specific protease belong to a family of cysteine proteases that mediate proteolytic events indispensable for biological phenomena such as cell death and inflammation. The first caspase was identified as an executioner of apoptotic cell death in the worm Caenorhabditis elegans. The executioners in both intrinsic and extrinsic pathways of cell death are the caspases, which are cysteine proteases with the specificity to cleave their substrates after aspartic acid residues. The first member of the caspase family, caspase-1, was initially known as interleukin-1β-converting enzyme ICE, an enzyme required for the. Interestingly, the inactivation of many caspase not only revealed their expected participation in apoptotic events but also in cytokine maturation, but also provided hints about the role of at least some of the caspase in cells. Protease biology is intimately linked to the functional consequences of substrate cleavage events. Human caspases are the family-destiny cysteine proteases that they are best known for. Caspases were first characterized as important biological players in inflammation and apoptotic cell death. The molecular pathways controlled by caspase-dependent substrate cleavage are evolutionarily conserved in eukaryotes and have evolved to regulate fundamental cellular processes by inducing apoptosis or causing inflammatory cell death. For a considerably long period of time, apoptosis remained a descriptive phenomenon in cell biology, until Sulston and Horvitz initiated a cell lineage study and delved deeper into programmed cell death in the nematode Caenorhabditis elegans C. elegans. The group demonstrated C. elegans somatic cells, the evolutionary conservation of caspases, and the fact that loss of CED-3. 42,107,948 42,107,948