Editing Caspase (section)

=== Cleavage ===
Once appropriately dimerised, the Caspases cleave at inter domain linker regions, forming a large and small subunit. This cleavage allows the active-site loops to take up a conformation favourable for enzymatic activity.<ref>{{Cite journal|last1=Riedl|first1=Stefan J.|last2=Shi|first2=Yigong|title=Molecular mechanisms of caspase regulation during apoptosis|journal=Nature Reviews Molecular Cell Biology|volume=5|issue=11|pages=897–907|doi=10.1038/nrm1496|pmid=15520809|date=Nov 2004|s2cid=19498556}}</ref>

''Cleavage of Initiator and Executioner caspases'' occur by different methods outlined in the table below.
* Initiator caspases auto-proteolytically cleave whereas Executioner caspases are cleaved by initiator caspases. This hierarchy allows an amplifying chain reaction or cascade for degrading cellular components, during controlled cell death.

{| class="wikitable"
|-
|Initiator Caspase
Caspase-8
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[[File:Caspase 8 final.png|thumb|300px|Inititator Pro-caspases have a prodomain that allows recruitment of other pro-caspases, which subsequently dimerise. Both pro-caspase molecules undergo cleavage by autocatalysis. This leads to removal of the prodomain and cleavage of the linker region between the large and small subunit. A heterotetramer is formed]]
 | valign=top |
[[File:Cas2 pdb.png|thumb|300px|PDB image of caspase 8 (3KJQ) in 'biological assembly'. Two shades of blue used to represent two small sunits, while two shades of purple represent two large subunits]]
|-
| Executioner
Caspase Caspase-3

||
[[File:Caspase 3 final.png|thumb|300px| Executioner caspases constitutively exist as homodimers. The red cuts represent regions where initiator caspases cleave the executioner caspases. The resulting small and large subunit of each Caspase-3 will associate, resulting in a heterotetramer.]]<ref>{{Cite journal|last1=Lavrik|first1=I.|last2=Krueger|first2=A.|last3=Schmitz|first3=I.|last4=Baumann|first4=S.|last5=Weyd|first5=H.|last6=Krammer|first6=P. H.|last7=Kirchhoff|first7=S.|date=2003-01-01|title=The active caspase-8 heterotetramer is formed at the CD95 DISC|journal=Cell Death & Differentiation|language=en|volume=10|issue=1|pages=144–145|doi=10.1038/sj.cdd.4401156|pmid=12655304|issn=1350-9047|doi-access=free}}</ref>
 ||
[[File:Cas4 pdb.png|thumb|300px|PDB image of Caspase 3 (4QTX) in 'biological assembly'. Two shades of blue used to represent two small sunits, while two shades of purple represent two large subunits]]
|}