Structure of IL-33 and its interaction with the ST2 and IL-1RAcP receptors--insight into heterotrimeric IL-1 signaling complexes.
Lingel, A., Weiss, T.M., Niebuhr, M., Pan, B., Appleton, B.A., Wiesmann, C., Bazan, J.F., Fairbrother, W.J.(2009) Structure 17: 1398-1410
- PubMed: 19836339 
- DOI: https://doi.org/10.1016/j.str.2009.08.009
- Primary Citation of Related Structures:  
2KLL - PubMed Abstract: 
Members of the interleukin-1 (IL-1) family of cytokines play major roles in host defense and immune system regulation in infectious and inflammatory diseases. IL-1 cytokines trigger a biological response in effector cells by assembling a heterotrimeric signaling complex with two IL-1 receptor chains, a high-affinity primary receptor and a low-affinity coreceptor. To gain insights into the signaling mechanism of the novel IL-1-like cytokine IL-33, we first solved its solution structure and then performed a detailed biochemical and structural characterization of the interaction between IL-33, its primary receptor ST2, and the coreceptor IL-1RAcP. Using nuclear magnetic resonance data, we obtained a model of the IL-33/ST2 complex in solution that is validated by small-angle X-ray scattering (SAXS) data and is similar to the IL-1beta/IL-1R1 complex. We extended our SAXS analysis to the IL-33/ST2/IL-1RAcP and IL-1beta/IL-1R1/IL-1RAcP complexes and propose a general model of the molecular architecture of IL-1 ternary signaling complexes.
Organizational Affiliation: 
Department of Protein Engineering, Genentech, South San Francisco, CA 94080, USA.