TY  - JOUR
AU  - Oroz, Javier
AU  - Barrera-Vilarmau, Susana
AU  - Alfonso, Carlos
AU  - Rivas, Germán
AU  - de Alba, Eva
TI  - ASC Pyrin Domain Self-associates and Binds NLRP3 Protein Using Equivalent Binding Interfaces.
JO  - The journal of biological chemistry
VL  - 291
IS  - 37
SN  - 0021-9258
CY  - Bethesda, Md.
PB  - Soc.60645
M1  - DZNE-2020-05082
SP  - 19487-19501
PY  - 2016
AB  - Death domain superfamily members typically act as adaptors mediating in the assembly of supramolecular complexes with critical apoptosis and inflammation functions. These modular proteins consist of death domains, death effector domains, caspase recruitment domains, and pyrin domains (PYD). Despite the high structural similarity among them, only homotypic interactions participate in complex formation, suggesting that subtle factors differentiate each interaction type. It is thus critical to identify these factors as an essential step toward the understanding of the molecular basis of apoptosis and inflammation. The proteins apoptosis-associated speck-like protein containing a CARD (ASC) and NLRP3 play key roles in the regulation of apoptosis and inflammation through self-association and protein-protein interactions mediated by their PYDs. To better understand the molecular basis of their function, we have characterized ASC and NLRP3 PYD self-association and their intermolecular interaction by solution NMR spectroscopy and analytical ultracentrifugation. We found that ASC self-associates and binds NLRP3 PYD through equivalent protein regions, with higher binding affinity for the latter. These regions are located at opposite sides of the protein allowing multimeric complex formation previously shown in ASC PYD fibril assemblies. We show that NLRP3 PYD coexists in solution as a monomer and highly populated large-order oligomerized species. Despite this, we determined its monomeric three-dimensional solution structure by NMR and characterized its binding to ASC PYD. Using our novel structural data, we propose molecular models of ASC·ASC and ASC·NLRP3 PYD early supramolecular complexes, providing new insights into the molecular mechanisms of inflammasome and apoptosis signaling.
KW  - CARD Signaling Adaptor Proteins
KW  - Cytoskeletal Proteins: chemistry
KW  - Cytoskeletal Proteins: genetics
KW  - Cytoskeletal Proteins: metabolism
KW  - Humans
KW  - Models, Molecular
KW  - NLR Family, Pyrin Domain-Containing 3 Protein: chemistry
KW  - NLR Family, Pyrin Domain-Containing 3 Protein: genetics
KW  - NLR Family, Pyrin Domain-Containing 3 Protein: metabolism
KW  - Nuclear Magnetic Resonance, Biomolecular
KW  - Protein Binding
KW  - Protein Structure, Quaternary
KW  - Pyrin Domain
KW  - Ultracentrifugation
KW  - CARD Signaling Adaptor Proteins (NLM Chemicals)
KW  - Cytoskeletal Proteins (NLM Chemicals)
KW  - NLR Family, Pyrin Domain-Containing 3 Protein (NLM Chemicals)
KW  - NLRP3 protein, human (NLM Chemicals)
KW  - PYCARD protein, human (NLM Chemicals)
LB  - PUB:(DE-HGF)16
C6  - pmid:27432880
C2  - pmc:PMC5016686
DO  - DOI:10.1074/jbc.M116.741082
UR  - https://pub.dzne.de/record/138760
ER  -