Author: Nat Pernick, M.D. (see Authors page)

Revised: 18 November 2015, last major update February 2012

Copyright: (c) 2003-2015,, Inc.

PubMed Search: caspases[title]

Caspases topics: Caspase 3, Caspase 7, Caspase 8, Caspase 9

Table of Contents
Definition / General | Diagrams
Definition / General
  • Cysteine proteases that act as essential initiators and executioners of apoptosis; also involved in necrosis and inflammation (Wikipedia)
  • Also called Cysteine-ASPartic proteASES or Cysteine-dependent ASPartate-directed proteASES
  • Act as apoptotic cell death effectors by cleaving polypeptides on the carboxyl end of aspartate residues
  • Synthesized as inactive proenzymes, may be activated by other caspases (initiator caspases), which cause a cascade of activation similar to coagulation or complement
  • Caspases are signaling proteases, designed for specific protein cleavage and not for protein degradation; they make one or two cuts in their target proteins and do not destroy protein structure, but rather modify it, thus creating gain or loss of function events that drive forward the apoptotic phenotype (J Cell Sci 2010;123:3209)
  • Final targets are nuclear lamins, ICAD/DFF45 (inhibitor of caspase activated DNase or DNA fragmentation factor 45), PARP (poly-ADP ribose polymerase), PAK2 (P 21-activated kinase 2)
  • Cleavage of ICAD allows the release of CAD, which relocalizes from the cytoplasm to the nucleus, where it cleaves genomic DNA

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Intrinisic and extrinsic pathways

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Intrinisic and extrinsic pathways