We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.

4zbw

From Proteopedia

Jump to: navigation, search

Crystal structure of death effector domain of Caspase8 in Homo Sapiens

Structural highlights

4zbw is a 2 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Method:	X-ray diffraction, Resolution 2.2Å
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Disease

CASP8_HUMAN Defects in CASP8 are the cause of caspase-8 deficiency (CASP8D) [MIM:607271. CASP8D is a disorder resembling autoimmune lymphoproliferative syndrome (ALPS). It is characterized by lymphadenopathy, splenomegaly, and defective CD95-induced apoptosis of peripheral blood lymphocytes (PBLs). It leads to defects in activation of T-lymphocytes, B-lymphocytes, and natural killer cells leading to immunodeficiency characterized by recurrent sinopulmonary and herpes simplex virus infections and poor responses to immunization.^[1]

Function

CASP8_HUMAN Most upstream protease of the activation cascade of caspases responsible for the TNFRSF6/FAS mediated and TNFRSF1A induced cell death. Binding to the adapter molecule FADD recruits it to either receptor. The resulting aggregate called death-inducing signaling complex (DISC) performs CASP8 proteolytic activation. The active dimeric enzyme is then liberated from the DISC and free to activate downstream apoptotic proteases. Proteolytic fragments of the N-terminal propeptide (termed CAP3, CAP5 and CAP6) are likely retained in the DISC. Cleaves and activates CASP3, CASP4, CASP6, CASP7, CASP9 and CASP10. May participate in the GZMB apoptotic pathways. Cleaves ADPRT. Hydrolyzes the small-molecule substrate, Ac-Asp-Glu-Val-Asp-|-AMC. Likely target for the cowpox virus CRMA death inhibitory protein. Isoform 5, isoform 6, isoform 7 and isoform 8 lack the catalytic site and may interfere with the pro-apoptotic activity of the complex.^[2] ^[3]

Publication Abstract from PubMed

Caspase-8 is a key mediator in various biological processes such as apoptosis, necroptosis, inflammation, T/B cells activation, and cell motility. Caspase-8 is characterized by the N-terminal tandem death effector domains (DEDs) and the C-terminal catalytic protease domain. The DEDs mediate diverse functions of caspase-8 through homotypic interactions of the DEDs between caspase-8 and its partner proteins. Here, we report the first crystal structure of the DEDs of caspase-8. The overall structure of the DEDs of caspase-8 is similar to that of the DEDs of vFLIP MC159, which is composed of two tandem death effector domains that closely associate with each other in a head-to-tail manner. Structural analysis reveals distinct differences in the region connecting helices alpha2b and alpha4b in the second DED of the DEDs between caspase-8 and MC159, in which the helix alpha3b in MC159 is replaced by a loop in caspase-8. Moreover, the different amino acids in this region might confer the distinct features of solubility and aggregation for the DEDs of caspase-8 and MC159.

Crystal structure of the death effector domains of caspase-8.,Shen C, Yue H, Pei J, Guo X, Wang T, Quan JM Biochem Biophys Res Commun. 2015 Jul 31;463(3):297-302. doi:, 10.1016/j.bbrc.2015.05.054. Epub 2015 May 20. PMID:26003730^[4]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Chun HJ, Zheng L, Ahmad M, Wang J, Speirs CK, Siegel RM, Dale JK, Puck J, Davis J, Hall CG, Skoda-Smith S, Atkinson TP, Straus SE, Lenardo MJ. Pleiotropic defects in lymphocyte activation caused by caspase-8 mutations lead to human immunodeficiency. Nature. 2002 Sep 26;419(6905):395-9. PMID:12353035 doi:10.1038/nature01063
↑ Himeji D, Horiuchi T, Tsukamoto H, Hayashi K, Watanabe T, Harada M. Characterization of caspase-8L: a novel isoform of caspase-8 that behaves as an inhibitor of the caspase cascade. Blood. 2002 Jun 1;99(11):4070-8. PMID:12010809
↑ Muzio M, Salvesen GS, Dixit VM. FLICE induced apoptosis in a cell-free system. Cleavage of caspase zymogens. J Biol Chem. 1997 Jan 31;272(5):2952-6. PMID:9006941
↑ Shen C, Yue H, Pei J, Guo X, Wang T, Quan JM. Crystal structure of the death effector domains of caspase-8. Biochem Biophys Res Commun. 2015 Jul 31;463(3):297-302. doi:, 10.1016/j.bbrc.2015.05.054. Epub 2015 May 20. PMID:26003730 doi:http://dx.doi.org/10.1016/j.bbrc.2015.05.054