Structure and assembly of the mouse ASC inflammasome by combined NMR spectroscopy and cryo-electron microscopy
Autor: | Adam Mazur, Francesco Ravotti, Lorenzo Sborgi, Henning Stahlberg, Anja Böckmann, Sina Reckel, Mohamed Chami, Sebastian Hiller, Matthias Huber, Mathias S. Dick, Petr Broz, Sebastian Scherer, Edward H. Egelman, Beat H. Meier, Venkata P. Dandey |
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Rok vydání: | 2015 |
Předmět: |
Models
Molecular Magnetic Resonance Spectroscopy CARD Signaling Adaptor Proteins Inflammasomes Protein Conformation Cryo-electron microscopy Blotting Western Biology Pyrin domain Protein filament Mice Protein structure medicine Animals Cloning Molecular Mice Knockout Microscopy Confocal Multidisciplinary Cryoelectron Microscopy Signal transducing adaptor protein Inflammasome Nuclear magnetic resonance spectroscopy Biological Sciences Cell biology Apoptosis Regulatory Proteins medicine.drug |
Zdroj: | PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA |
ISSN: | 1091-6490 0027-8424 |
Popis: | 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. |
Databáze: | OpenAIRE |
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