5H8O

Crystal structure of an ASC-binding nanobody in complex with the CARD domain of ASC

Summary for 5H8O

• Entry DOI: 10.2210/pdb5h8o/pdb
• Related: 5H8D
• Descriptor: VHH nanobody, Apoptosis-associated speck-like protein containing a CARD (2 entities in total)
• Functional Keywords: vhh nanobody, asc-binding, antibody fragment, inflammasome, immune system
• Biological source: Lama glama (llama); More
• Cellular location: Cytoplasm: Q9ULZ3
• Total number of polymer chains: 2
• Total formula weight: 21717.33

Authors

Lu, A.,Schmidt, F.I.,Ruan, J.,Tang, C.,Wu, H.,Ploegh, H.L. (deposition date: 2015-12-23, release date: 2016-04-06, Last modification date: 2024-10-16)

Primary citation

Schmidt, F.I.,Lu, A.,Chen, J.W.,Ruan, J.,Tang, C.,Wu, H.,Ploegh, H.L.
A single domain antibody fragment that recognizes the adaptor ASC defines the role of ASC domains in inflammasome assembly.
J.Exp.Med., 213:771-790, 2016

PubMed Abstract: Myeloid cells assemble inflammasomes in response to infection or cell damage; cytosolic sensors activate pro-caspase-1, indirectly for the most part, via the adaptors ASC and NLRC4. This leads to secretion of proinflammatory cytokines and pyroptosis. To explore complex formation under physiological conditions, we generated an alpaca single domain antibody, VHHASC, which specifically recognizes the CARD of human ASC via its type II interface. VHHASC not only impairs ASC(CARD) interactions in vitro, but also inhibits inflammasome activation in response to NLRP3, AIM2, and NAIP triggers when expressed in living cells, highlighting a role of ASC in all three types of inflammasomes. VHHASC leaves the Pyrin domain of ASC functional and stabilizes a filamentous intermediate of inflammasome activation. Incorporation of VHHASC-EGFP into these structures allowed the visualization of endogenous ASC(PYD) filaments for the first time. These data revealed that cross-linking of ASC(PYD) filaments via ASC(CARD) mediates the assembly of ASC foci.

PubMed: 27069117
DOI: 10.1084/jem.20151790

Experimental method

X-RAY DIFFRACTION (4.206 Å)