Structural insights into the disruption of TNF-TNFR1 signalling by small molecules stabilising a distorted TNF.
McMillan, D., Martinez-Fleites, C., Porter, J., Fox 3rd, D., Davis, R., Mori, P., Ceska, T., Carrington, B., Lawson, A., Bourne, T., O'Connell, J.(2021) Nat Commun 12: 582-582
- PubMed: 33495441 
- DOI: https://doi.org/10.1038/s41467-020-20828-3
- Primary Citation of Related Structures:  
7KP7, 7KP8, 7KP9 - PubMed Abstract: 
Tumour necrosis factor (TNF) is a trimeric protein which signals through two membrane receptors, TNFR1 and TNFR2. Previously, we identified small molecules that inhibit human TNF by stabilising a distorted trimer and reduce the number of receptors bound to TNF from three to two. Here we present a biochemical and structural characterisation of the small molecule-stabilised TNF-TNFR1 complex, providing insights into how a distorted TNF trimer can alter signalling function. We demonstrate that the inhibitors reduce the binding affinity of TNF to the third TNFR1 molecule. In support of this, we show by X-ray crystallography that the inhibitor-bound, distorted, TNF trimer forms a complex with a dimer of TNFR1 molecules. This observation, along with data from a solution-based network assembly assay, leads us to suggest a model for TNF signalling based on TNF-TNFR1 clusters, which are disrupted by small molecule inhibitors.
Organizational Affiliation: 
UCB Pharma, Slough, SL1 3WE, UK. david.mcmillan@ucb.com.