TY - JOUR
T1 - Structural and functional analysis of the NLRP4 pyrin domain
AU - Eibl, Clarissa
AU - Grigoriu, Simina
AU - Hessenberger, Manuel
AU - Wenger, Julia
AU - Puehringer, Sandra
AU - Pinheiro, Anderson S
AU - Wagner, Roland N
AU - Proell, Martina
AU - Reed, John C
AU - Page, Rebecca
AU - Diederichs, Kay
AU - Peti, Wolfgang
PY - 2012/9/18
Y1 - 2012/9/18
N2 - NLRP4 is a member of the nucleotide-binding and leucine-rich repeat receptor (NLR) family of cytosolic receptors and a member of an inflammation signaling cascade. Here, we present the crystal structure of the NLRP4 pyrin domain (PYD) at 2.3 Å resolution. The NLRP4 PYD is a member of the death domain (DD) superfamily and adopts a DD fold consisting of six α-helices tightly packed around a hydrophobic core, with a highly charged surface that is typical of PYDs. Importantly, however, we identified several differences between the NLRP4 PYD crystal structure and other PYD structures that are significant enough to affect NLRP4 function and its interactions with binding partners. Notably, the length of helix α3 and the α2-α3 connecting loop in the NLRP4 PYD are unique among PYDs. The apoptosis-associated speck-like protein containing a CARD (ASC) is an adaptor protein whose interactions with a number of distinct PYDs are believed to be critical for activation of the inflammatory response. Here, we use co-immunoprecipitation, yeast two-hybrid, and nuclear magnetic resonance chemical shift perturbation analysis to demonstrate that, despite being important for activation of the inflammatory response and sharing several similarities with other known ASC-interacting PYDs (i.e., ASC2), NLRP4 does not interact with the adaptor protein ASC. Thus, we propose that the factors governing homotypic PYD interactions are more complex than the currently accepted model, which states that complementary charged surfaces are the main determinants of PYD-PYD interaction specificity.
AB - NLRP4 is a member of the nucleotide-binding and leucine-rich repeat receptor (NLR) family of cytosolic receptors and a member of an inflammation signaling cascade. Here, we present the crystal structure of the NLRP4 pyrin domain (PYD) at 2.3 Å resolution. The NLRP4 PYD is a member of the death domain (DD) superfamily and adopts a DD fold consisting of six α-helices tightly packed around a hydrophobic core, with a highly charged surface that is typical of PYDs. Importantly, however, we identified several differences between the NLRP4 PYD crystal structure and other PYD structures that are significant enough to affect NLRP4 function and its interactions with binding partners. Notably, the length of helix α3 and the α2-α3 connecting loop in the NLRP4 PYD are unique among PYDs. The apoptosis-associated speck-like protein containing a CARD (ASC) is an adaptor protein whose interactions with a number of distinct PYDs are believed to be critical for activation of the inflammatory response. Here, we use co-immunoprecipitation, yeast two-hybrid, and nuclear magnetic resonance chemical shift perturbation analysis to demonstrate that, despite being important for activation of the inflammatory response and sharing several similarities with other known ASC-interacting PYDs (i.e., ASC2), NLRP4 does not interact with the adaptor protein ASC. Thus, we propose that the factors governing homotypic PYD interactions are more complex than the currently accepted model, which states that complementary charged surfaces are the main determinants of PYD-PYD interaction specificity.
KW - Adaptor Proteins, Signal Transducing
KW - Crystallography, X-Ray
KW - Humans
KW - Models, Molecular
KW - Nuclear Magnetic Resonance, Biomolecular
KW - Protein Folding
KW - Protein Structure, Secondary
KW - Protein Structure, Tertiary
KW - Repetitive Sequences, Amino Acid
KW - Repressor Proteins/chemistry
KW - Structure-Activity Relationship
UR - http://www.scopus.com/inward/record.url?scp=84866386287&partnerID=8YFLogxK
U2 - 10.1021/bi3007059
DO - 10.1021/bi3007059
M3 - Journal article
C2 - 22928810
SN - 0006-2960
VL - 51
SP - 7330
EP - 7341
JO - Biochemistry
JF - Biochemistry
IS - 37
ER -