Structure of FADD/Caspase-8/cFLIP death effector domain assemblyStructure of FADD/Caspase-8/cFLIP death effector domain assembly

Structural highlights

8yd8 is a 10 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 3.11Å
Resources:FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

CFLAR_HUMAN Apoptosis regulator protein which may function as a crucial link between cell survival and cell death pathways in mammalian cells. Acts as an inhibitor of TNFRSF6 mediated apoptosis. A proteolytic fragment (p43) is likely retained in the death-inducing signaling complex (DISC) thereby blocking further recruitment and processing of caspase-8 at the complex. Full length and shorter isoforms have been shown either to induce apoptosis or to reduce TNFRSF-triggered apoptosis. Lacks enzymatic (caspase) activity.[1]

Publication Abstract from PubMed

Fas-associated protein with death domain (FADD), procaspase-8, and cellular FLICE-inhibitory proteins (cFLIP) assemble through death-effector domains (DEDs), directing death receptor signaling towards cell survival or apoptosis. Understanding their three-dimensional regulatory mechanism has been limited by the absence of atomic coordinates for their ternary DED complex. By employing X-ray crystallography and cryogenic electron microscopy (cryo-EM), we present the atomic coordinates of human FADD-procaspase-8-cFLIP complexes, revealing structural insights into these critical interactions. These structures illustrate how FADD and cFLIP orchestrate the assembly of caspase-8-containing complexes and offer mechanistic explanations for their role in promoting or inhibiting apoptotic and necroptotic signaling. A helical procaspase-8-cFLIP hetero-double layer in the complex appears to promote limited caspase-8 activation for cell survival. Our structure-guided mutagenesis supports the role of the triple-FADD complex in caspase-8 activation and in regulating receptor-interacting protein kinase 1 (RIPK1). These results propose a unified mechanism for DED assembly and procaspase-8 activation in the regulation of apoptotic and necroptotic signaling across various cellular pathways involved in development, innate immunity, and disease.

Deciphering DED assembly mechanisms in FADD-procaspase-8-cFLIP complexes regulating apoptosis.,Yang CY, Lien CI, Tseng YC, Tu YF, Kulczyk AW, Lu YC, Wang YT, Su TW, Hsu LC, Lo YC, Lin SC Nat Commun. 2024 May 6;15(1):3791. doi: 10.1038/s41467-024-47990-2. PMID:38710704[2]

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

References

  1. Scaffidi C, Schmitz I, Krammer PH, Peter ME. The role of c-FLIP in modulation of CD95-induced apoptosis. J Biol Chem. 1999 Jan 15;274(3):1541-8. PMID:9880531
  2. Yang CY, Lien CI, Tseng YC, Tu YF, Kulczyk AW, Lu YC, Wang YT, Su TW, Hsu LC, Lo YC, Lin SC. Deciphering DED assembly mechanisms in FADD-procaspase-8-cFLIP complexes regulating apoptosis. Nat Commun. 2024 May 6;15(1):3791. PMID:38710704 doi:10.1038/s41467-024-47990-2

8yd8, resolution 3.11Å

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