Structure and assembly of the mouse ASC inflammasome by combined NMR spectroscopy and cryo-electron microscopy.

Details

Serval ID
serval:BIB_2D34457006B7
Type
Article: article from journal or magazin.
Collection
Publications
Title
Structure and assembly of the mouse ASC inflammasome by combined NMR spectroscopy and cryo-electron microscopy.
Journal
Proceedings of the National Academy of Sciences of the United States of America
Author(s)
Sborgi L., Ravotti F., Dandey V.P., Dick M.S., Mazur A., Reckel S., Chami M., Scherer S., Huber M., Böckmann A., Egelman E.H., Stahlberg H., Broz P., Meier B.H., Hiller S.
ISSN
1091-6490 (Electronic)
ISSN-L
0027-8424
Publication state
Published
Issued date
2015
Peer-reviewed
Oui
Volume
112
Number
43
Pages
13237-13242
Language
english
Abstract
Inflammasomes are multiprotein complexes that control the innate immune response by activating caspase-1, thus promoting the secretion of cytokines in response to invading pathogens and endogenous triggers. Assembly of inflammasomes is induced by activation of a receptor protein. Many inflammasome receptors require the adapter protein ASC [apoptosis-associated speck-like protein containing a caspase-recruitment domain (CARD)], which consists of two domains, the N-terminal pyrin domain (PYD) and the C-terminal CARD. Upon activation, ASC forms large oligomeric filaments, which facilitate procaspase-1 recruitment. Here, we characterize the structure and filament formation of mouse ASC in vitro at atomic resolution. Information from cryo-electron microscopy and solid-state NMR spectroscopy is combined in a single structure calculation to obtain the atomic-resolution structure of the ASC filament. Perturbations of NMR resonances upon filament formation monitor the specific binding interfaces of ASC-PYD association. Importantly, NMR experiments show the rigidity of the PYD forming the core of the filament as well as the high mobility of the CARD relative to this core. The findings are validated by structure-based mutagenesis experiments in cultured macrophages. The 3D structure of the mouse ASC-PYD filament is highly similar to the recently determined human ASC-PYD filament, suggesting evolutionary conservation of ASC-dependent inflammasome mechanisms.

Keywords
Animals, Apoptosis Regulatory Proteins/chemistry, Apoptosis Regulatory Proteins/genetics, Apoptosis Regulatory Proteins/isolation & purification, Blotting, Western, CARD Signaling Adaptor Proteins, Cloning, Molecular, Cryoelectron Microscopy, Inflammasomes/chemistry, Inflammasomes/isolation & purification, Magnetic Resonance Spectroscopy, Mice, Mice, Knockout, Microscopy, Confocal, Models, Molecular, Protein Conformation, ASC speck, inflammation, innate immune response, protein filament, protein structure
Pubmed
Web of science
Open Access
Yes
Create date
25/10/2017 11:05
Last modification date
20/08/2019 14:12
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