6l9w
Crystal structure of mouse TIFA (T9E/C36S mutant)
Structural highlights
FunctionTIFA_MOUSE Adapter molecule that plays a key role in the activation of proinflammatory NF-kappa-B signaling following detection of bacterial pathogen-associated molecular pattern metabolites (PAMPs) (PubMed:11798190). Promotes activation of an innate immune response by inducing the oligomerization and polyubiquitination of TRAF6, which leads to the activation of TAK1 and IKK through a proteasome-independent mechanism (By similarity). TIFA-dependent innate immune response is triggered by ADP-D-glycero-beta-D-manno-heptose (ADP-Heptose), a potent PAMP present in all Gram-negative and some Gram-positive bacteria: ADP-Heptose is recognized by ALPK1, which phosphorylates TIFA at Thr-9, leading to TIFA homooligomerization and subsequent activation of proinflammatory NF-kappa-B signaling (By similarity).[UniProtKB:Q96CG3][1] Publication Abstract from PubMedTRAF-interacting protein with a forkhead-associated (FHA) domain (TIFA), originally identified as an adaptor protein of TRAF6, has recently been shown to be involved in innate immunity, induced by a pathogen-associated molecular pattern (PAMP). ADP-beta-D-manno-heptose, a newly identified PAMP, binds to alpha-kinase 1 (ALPK1) and activates its kinase activity to phosphorylate TIFA. Phosphorylation triggers TIFA oligomerisation and formation of a subsequent TIFA-TRAF6 oligomeric complex for ubiquitination of TRAF6, eventually leading to NF-kappaB activation. However, the structural basis of TIFA-dependent TRAF6 signalling, especially oligomer formation of the TIFA-TRAF6 complex remains unknown. In the present study, we determined the crystal structures of mouse TIFA and two TIFA mutants-Thr9 mutated to either Asp or Glu to mimic the phosphorylation state-to obtain the structural information for oligomer formation of the TIFA-TRAF6 complex. Crystal structures show the dimer formation of mouse TIFA to be similar to that of human TIFA, which was previously reported. This dimeric structure is consistent with the solution structure obtained from small angle X-ray scattering analysis. In addition to the structural analysis, we examined the molecular assembly of TIFA and the TIFA-TRAF6 complex by size-exclusion chromatography, and suggested a model for the TIFA-TRAF6 signalling complex. Structural analysis of TIFA: Insight into TIFA-dependent signal transduction in innate immunity.,Nakamura T, Hashikawa C, Okabe K, Yokote Y, Chirifu M, Toma-Fukai S, Nakamura N, Matsuo M, Kamikariya M, Okamoto Y, Gohda J, Akiyama T, Semba K, Ikemizu S, Otsuka M, Inoue JI, Yamagata Y Sci Rep. 2020 Mar 20;10(1):5152. doi: 10.1038/s41598-020-61972-6. PMID:32198460[2] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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