Structures of the extracellular domain of the type I tumor necrosis factor receptor.
Naismith, J.H., Devine, T.Q., Kohno, T., Sprang, S.R.(1996) Structure 4: 1251-1262
- PubMed: 8939750 
- DOI: https://doi.org/10.1016/s0969-2126(96)00134-7
- Primary Citation of Related Structures:  
1EXT - PubMed Abstract: 
Tumor necrosis factor (TNF) is a powerful cytokine that is involved in immune and pro-inflammatory responses. Two TNF receptors that belong to the cysteine-rich low affinity nerve growth factor receptor family (TNF-R1 and TNF-R2) are the sole mediators of TNF signalling. Signalling is thought to occur when a trimer of TNF binds to the extracellular domains of two or three receptor molecules, which permits aggregation and activation of the cytoplasmic domains. The complex is then internalized within an endocytic vesicle, whereupon it dissociates at low pH. Structure of the soluble extracellular domain of the receptor (sTNF-R1) both in the unliganded and TNF-bound state have previously been determined. In both instances, the fourth subdomain of the receptor was found to be partly disordered. In the unliganded state at pH 7.5, the extracellular domain forms two distinct types of dimer, parallel and antiparallel; the antiparallel dimer occludes the TNF-binding.
Organizational Affiliation: 
Centre for Biomolecular Sciences, Purdie Building, The University, St. Andrews, KY16 9ST, Scotland, UK. naismith@st-andrews.ac.uk