How convergent and divergent signaling pathways are mediated by card-card interactions

PRRs play an essential role in detecting pathogenic infections and propagating such immune signals to downstream effectors. NLRs act as a classic subfamily of PRRs, including NOD1/NOD2 and NLRC4. NOD1 and NOD2 share a same adaptor protein – RIP2 – that is critical for downstream signaling. The CARD...

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Bibliographic Details
Main Author: Qin, Gong
Other Authors: Wu Bin
Format: Thesis-Doctor of Philosophy
Language:English
Published: Nanyang Technological University 2020
Subjects:
Online Access:https://hdl.handle.net/10356/137877
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Institution: Nanyang Technological University
Language: English
Description
Summary:PRRs play an essential role in detecting pathogenic infections and propagating such immune signals to downstream effectors. NLRs act as a classic subfamily of PRRs, including NOD1/NOD2 and NLRC4. NOD1 and NOD2 share a same adaptor protein – RIP2 – that is critical for downstream signaling. The CARD domain of RIP2 oligomerizes to form a filamentous structure in responses to activated NOD1-CARD or NOD2-CARD. To investigate the signaling transduction process, the RIP2-CARD oligomeric complex, named RIPosome, was reconstituted and expressed. The structure of filamentous RIP2-CARD complex was resolved at a near-atomic resolution of 3.6 Å. With this high-resolution structure, the mechanism of how two different CARD domains initiate RIP2 oligomerization from NOD1 and NOD2 was demonstrated. Plus, NLRC4-CARD was found to form filamentous oligomers upon activation, with the filament structure solved by a similar method as that for RIP2-CARD filament at 3.3Å resolution. The atomic-resolution structure provides important information reveals the importance of inflammasomes in immune signals transduction.