Caspase 6 Explained

Caspase-6 is an enzyme that in humans is encoded by the CASP6 gene.[1] [2] CASP6 orthologs[3] have been identified in numerous mammals for which complete genome data are available. Unique orthologs are also present in birds, lizards, lissamphibians, and teleosts. Caspase-6 has known functions in apoptosis,[4] early immune response[5] [6] and neurodegeneration in Huntington's and Alzheimer's disease.[7]

Function

This gene encodes a protein that is a member of the cysteine-aspartic acid protease (caspase) family. Sequential activation of caspases plays a central role in the execution-phase of cell apoptosis. Caspases exist as inactive proenzymes that undergo proteolytic processing at conserved aspartic residues to produce two subunits, large and small, that dimerize to form the active enzyme. This protein is processed by caspases 7, 8 and 10, and is thought to function as a downstream enzyme in the caspase activation cascade. Caspase 6 can also undergo self-processing without other members of the caspase family.[8] Alternative splicing of this gene results in two transcript variants that encode different isoforms.[9]

Caspase-6 plays a role in the early immune response via de-repression. It reduces the expression of the immunosuppressant cytokine interleukin-10 and cleaves the macrophage suppressing IRAK-M.

With respect to neurodegeneration, caspase-6 cleaves HTT in Huntington's and APP in Alzheimer's disease. Resulting in both cases in protein aggregation of the fragments.

Interactions

Caspase 6 has been shown to interact with Caspase 8.[10] [11] [12]

See also

References

Further reading

External links

Notes and References

  1. Tiso N, Pallavicini A, Muraro T, Zimbello R, Apolloni E, Valle G, Lanfranchi G, Danieli GA . Chromosomal localization of the human genes, CPP32, Mch2, Mch3, and Ich-1, involved in cellular apoptosis . Biochem Biophys Res Commun . 225 . 3 . 983–9 . Oct 1996 . 8780721 . 10.1006/bbrc.1996.1282 . 11577/2461073 . free .
  2. Fernandes-Alnemri T, Litwack G, Alnemri ES . Mch2, a new member of the apoptotic Ced-3/Ice cysteine protease gene family . Cancer Res . 55 . 13 . 2737–42 . Aug 1995 . 7796396 .
  3. Web site: OrthoMaM phylogenetic marker: CASP6 coding sequence . 2009-12-20 . https://web.archive.org/web/20160303175915/http://www.orthomam.univ-montp2.fr/orthomam/data/cds/detailMarkers/ENSG00000138794_CASP6.xml . 2016-03-03 . dead .
  4. Cohen. Gerald M.. 1997-08-15. Caspases: the executioners of apoptosis. Biochemical Journal. en. 326. 1. 1–16. 10.1042/bj3260001. 0264-6021. 9337844. 1218630.
  5. Bartel. Alexander. Göhler. André. Hopf. Verena. Breitbach. Katrin. 2017-07-07. Caspase-6 mediates resistance against Burkholderia pseudomallei infection and influences the expression of detrimental cytokines. PLOS ONE. 12. 7. e0180203. 10.1371/journal.pone.0180203. 28686630. 5501493. 2017PLoSO..1280203B. 1932-6203. free.
  6. Kobayashi. Hiroshi. Nolan. Anna. Naveed. Bushra. Hoshino. Yoshihiko. Segal. Leopoldo N.. Fujita. Yoko. Rom. William N.. Weiden. Michael D.. 2011-01-01. Neutrophils Activate Alveolar Macrophages by Producing Caspase-6–Mediated Cleavage of IL-1 Receptor-Associated Kinase-M. The Journal of Immunology. en. 186. 1. 403–410. 10.4049/jimmunol.1001906. 0022-1767. 3151149. 21098228.
  7. Graham. Rona K.. Ehrnhoefer. Dagmar E.. Hayden. Michael R.. 2011-12-01. Caspase-6 and neurodegeneration. Trends in Neurosciences. en. 34. 12. 646–656. 10.1016/j.tins.2011.09.001. 0166-2236. 22018804. 1603684.
  8. Wang XJ, Cao Q, Liu X, Wang KT, Mi W, Zhang Y, Li LF, LeBlanc AC, Su XD . Crystal structures of human caspase 6 reveal a new mechanism for intramolecular cleavage self-activation . EMBO Rep . 11 . 11 . 841–7 . Nov 2010 . 20890311 . 2966951 . 10.1038/embor.2010.141 .
  9. Web site: Entrez Gene: CASP6 caspase 6, apoptosis-related cysteine peptidase.
  10. Cowling V, Downward J . Caspase-6 is the direct activator of caspase-8 in the cytochrome c-induced apoptosis pathway: absolute requirement for removal of caspase-6 prodomain . Cell Death Differ. . 9 . 10 . 1046–56 . Oct 2002 . 12232792 . 10.1038/sj.cdd.4401065 . free .
  11. Guo Y, Srinivasula SM, Druilhe A, Fernandes-Alnemri T, Alnemri ES . Caspase-2 induces apoptosis by releasing proapoptotic proteins from mitochondria . J. Biol. Chem. . 277 . 16 . 13430–7 . Apr 2002 . 11832478 . 10.1074/jbc.M108029200 . free .
  12. Srinivasula SM, Ahmad M, Fernandes-Alnemri T, Litwack G, Alnemri ES . Molecular ordering of the Fas-apoptotic pathway: The Fas/APO-1 protease Mch5 is a CrmA-inhibitable protease that activates multiple Ced-3/ICE-like cysteine proteases . . 93 . 25 . 14486–91 . Dec 1996 . 8962078 . 26159 . 10.1073/pnas.93.25.14486 . 1996PNAS...9314486S . free .