Download MendeleyShigella flexneri evades LPS ubiquitylation through IpaH1.4-mediated degradation of RNF213.
Naydenova, K., Boyle, K.B., Pathe, C., Pothukuchi, P., Crespillo-Casado, A., Scharte, F., Hammoudi, P.M., Otten, E.G., Alto, N.M., Randow, F.(2025) Nat Struct Mol Biol 32: 1741-1751
- PubMed: 40205224
- DOI: https://doi.org/10.1038/s41594-025-01530-8
- Primary Citation of Related Structures:
9G08, 9G09 - PubMed Abstract:
Pathogens have evolved diverse strategies to counteract host immunity. Ubiquitylation of lipopolysaccharide (LPS) on cytosol-invading bacteria by the E3 ligase RNF213 creates 'eat me' signals for antibacterial autophagy, but whether and how cytosol-adapted bacteria avoid LPS ubiquitylation remains poorly understood. Here, we show that the enterobacterium Shigella flexneri actively antagonizes LPS ubiquitylation through IpaH1.4, a secreted effector protein with ubiquitin E3 ligase activity. IpaH1.4 binds to RNF213, ubiquitylates it and targets it for proteasomal degradation, thus counteracting host-protective LPS ubiquitylation. To understand how IpaH1.4 recognizes RNF213, we determined the cryogenic electron microscopy structure of the IpaH1.4-RNF213 complex. The specificity of the interaction is achieved through the leucine-rich repeat of IpaH1.4, which binds the RING domain of RNF213 by hijacking the conserved RING interface required for binding to ubiquitin-charged E2 enzymes. IpaH1.4 also targets other E3 ligases involved in inflammation and immunity through binding to the E2-interacting face of their RING domains, including the E3 ligase LUBAC that is required for the synthesis of M1-linked ubiquitin chains on cytosol-invading bacteria downstream of RNF213. We conclude that IpaH1.4 has evolved to antagonize multiple antibacterial and proinflammatory host E3 ligases.
- Division of Protein and Nucleic Acid Chemistry, MRC Laboratory of Molecular Biology, Cambridge, UK.
Organizational Affiliation:
