PROSITE documentation PDOC00864
Caspase family signatures and profiles


Interleukin-1 β converting enzyme (EC (ICE) [1,2] is responsible for the cleavage of the IL-1 β precursor at an Asp-Ala bond to generate the mature biologically active cytokine. ICE a thiol protease composed of two subunits of 10 (p10) and 20 Kd (p20), both derived by the autocleavage of a 45 Kd precursor (p45). Two residues are implicated in the catalytic mechanism: a cysteine and an histidine. They are located in the P20 subunit after cleavage of the precursor. ICE belongs to a family of peptidases [3] which is implicated in programmed cell death (apoptosis) and which has been termed 'caspase' for cysteine aspase. ICE is known as Caspase-1 and the other members of this family [4] are:

  • Caspase-2 (ICH-1, NEDD-2).
  • Caspase-3 (also known as apopain, CPP32, Yama), a protease which, at the onset of apoptosis, proteolytically cleaves poly(ADP-ribose) polymerase (see <PDOC00360>) at an Asp-Gly bond.
  • Caspase-4 (ICH-2, TX, ICErel-II).
  • Caspase-5 (ICH-3, TY, ICErel-III).
  • Caspase-6 (MCH-2).
  • Caspase-7 (MCH-3, ICE-LAP3, CMH-1, SCA-2, LICE2).
  • Caspase-8 (MCH-5, MACH, FLICE).
  • Caspase-9 (MCH-6, ICE-LAP6).
  • Caspase-10 (MCH-4, FLICE2).
  • Caspase-11.
  • Caspase-12.
  • Caspase-13 (ERICE).
  • Caspase-14.
  • Caenorhabditis elegans ced-3 involved in the initiation of apoptosis.
  • Drosophila Ice.

We have developed signature patterns for both active site residues. We also developed two profiles, one specific for the caspase P10 subunit and one for the caspase P20 subunit.


These proteins belong to family C14 in the classification of peptidases [5,E1].

Last update:

December 2004 / Patterns and text revised.


Technical section

PROSITE methods (with tools and information) covered by this documentation:

CASPASE_P10, PS50207; Caspase family p10 domain profile  (MATRIX)

CASPASE_P20, PS50208; Caspase family p20 domain profile  (MATRIX)

CASPASE_CYS, PS01122; Caspase family cysteine active site  (PATTERN)

CASPASE_HIS, PS01121; Caspase family histidine active site  (PATTERN)


1AuthorsThornberry N.A. Molineaux S.M.
TitleInterleukin-1 beta converting enzyme: a novel cysteine protease required for IL-1 beta production and implicated in programmed cell death.
SourceProtein Sci. 4:3-12(1995).
PubMed ID7773174

2AuthorsKumar S.
TitleICE-like proteases in apoptosis.
SourceTrends Biochem. Sci. 20:198-202(1995).
PubMed ID7610484

3AuthorsNicholson D.W. Thornberry N.A.
TitleCaspases: killer proteases.
SourceTrends Biochem. Sci. 22:299-306(1997).
PubMed ID9270303

4AuthorsAlnemri E.S. Livingston D.J. Nicholson D.W. Salvesen G. Thornberry N.A. Wong W.W. Yuan J.
TitleHuman ICE/CED-3 protease nomenclature.
SourceCell 87:171-171(1996).
PubMed ID8861900

5AuthorsRawlings N.D. Barrett A.J.
TitleEvolutionary families of peptidases.
SourceBiochem. J. 290:205-218(1993).
PubMed ID8439290


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