EMD-34843
C3aR-Gi-apo protein complex
EMD-34843
Single-particle3.2 Å
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Map released: 10/05/2023
Last modified: 13/11/2024
Sample Organism:
Homo sapiens,
Rattus norvegicus,
Bos taurus
Sample: C3aR-Gi-apo protein complex
Fitted models: 8hk3 (Avg. Q-score: 0.438)
Deposition Authors: Wang Y
,
Liu W,
Xu Y
,
Zhuang Y
,
Xu HE
Sample: C3aR-Gi-apo protein complex
Fitted models: 8hk3 (Avg. Q-score: 0.438)
Deposition Authors: Wang Y
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Revealing the signaling of complement receptors C3aR and C5aR1 by anaphylatoxins.
Wang Y
,
Liu W,
Xu Y
,
He X
,
Yuan Q,
Luo P,
Fan W,
Zhu J,
Zhang X,
Cheng X
,
Jiang Y,
Xu HE
,
Zhuang Y
(2023) Nat Chem Biol , 19 , 1351 - 1360
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(2023) Nat Chem Biol , 19 , 1351 - 1360
Abstract:
The complement receptors C3aR and C5aR1, whose signaling is selectively activated by anaphylatoxins C3a and C5a, are important regulators of both innate and adaptive immune responses. Dysregulations of C3aR and C5aR1 signaling lead to multiple inflammatory disorders, including sepsis, asthma and acute respiratory distress syndrome. The mechanism underlying endogenous anaphylatoxin recognition and activation of C3aR and C5aR1 remains elusive. Here we reported the structures of C3a-bound C3aR and C5a-bound C5aR1 as well as an apo-C3aR structure. These structures, combined with mutagenesis analysis, reveal a conserved recognition pattern of anaphylatoxins to the complement receptors that is different from chemokine receptors, unique pocket topologies of C3aR and C5aR1 that mediate ligand selectivity, and a common mechanism of receptor activation. These results provide crucial insights into the molecular understanding of C3aR and C5aR1 signaling and structural templates for rational drug design for treating inflammation disorders.
The complement receptors C3aR and C5aR1, whose signaling is selectively activated by anaphylatoxins C3a and C5a, are important regulators of both innate and adaptive immune responses. Dysregulations of C3aR and C5aR1 signaling lead to multiple inflammatory disorders, including sepsis, asthma and acute respiratory distress syndrome. The mechanism underlying endogenous anaphylatoxin recognition and activation of C3aR and C5aR1 remains elusive. Here we reported the structures of C3a-bound C3aR and C5a-bound C5aR1 as well as an apo-C3aR structure. These structures, combined with mutagenesis analysis, reveal a conserved recognition pattern of anaphylatoxins to the complement receptors that is different from chemokine receptors, unique pocket topologies of C3aR and C5aR1 that mediate ligand selectivity, and a common mechanism of receptor activation. These results provide crucial insights into the molecular understanding of C3aR and C5aR1 signaling and structural templates for rational drug design for treating inflammation disorders.