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Updated: Jun 10, 2025
07:17
Measuring Composition of CD95 Death-Inducing Signaling Complex and Processing of Procaspase-8 in this Complex
Published on: August 2, 2021
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Reverse hierarchical DED assembly in the cFLIP-procaspase-8 and cFLIP-procaspase-8-FADD complexes
Chao-Yu Yang1, Yi-Chun Tseng1,2, Yi-Fan Tu2
1Genomics Research Center, Academia Sinica, Taipei, 11529, Taiwan.
Nature Communications
|October 17, 2024
Summary
Cellular FLIP (cFLIP) forms novel complexes with procaspase-8, independent of FADD, revealing new mechanisms of cell death resistance and immortality in tumor cells.
Area of Science:
- Cellular and Molecular Biology
- Structural Biology
- Cancer Biology
Background:
- Cellular FLIP (cFLIP) is a key regulator of apoptosis, often overexpressed in cancer cells.
- The precise structural mechanisms of cFLIP in regulating death signaling complexes were previously unknown.
Purpose of the Study:
- To elucidate the three-dimensional structure of cFLIP-mediated death effector domain (DED) complexes.
- To uncover the regulatory mechanisms governing cell death pathways involving cFLIP and procaspase-8.
Main Methods:
- Crystal structure determination
- Cryo-electron microscopy (cryo-EM)
- Structure-guided mutagenesis experiments
Main Results:
- Revealed an unconventional binary tandem DED complex formed by cFLIP and procaspase-8, independent of FADD.
- Demonstrated that this complex recruits FADD, allosterically modulates cFLIP, and partially activates caspase-8 for RIPK1 cleavage.
- Provided insights into apoptosis and necroptosis resistance mechanisms.
Conclusions:
- cFLIP and procaspase-8 form a FADD-independent complex that influences cell death signaling.
- This finding offers a unified model for how multiprotein helical assemblies govern cell fate decisions and immortality.
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