PMID: 27818100

Authors:

Yatime L, Betzer C, Jensen RK, Mortensen S, Jensen PH, Andersen GR

Title:

The Structure of the RAGE:S100A6 Complex Reveals a Unique Mode of Homodimerization for S100 Proteins.

Journal:

Structure. 2016 Dec 6;24(12):2043-2052. doi: 10.1016/j.str.2016.09.011. Epub 2016, Nov 3.

Abstract:

S100 proteins are calcium-dependent regulators of homeostatic processes. Upon cellular response to stress, and notably during tumorigenesis, they relocalize to the extracellular environment where they induce pro-inflammatory signals by activating the receptor for advanced glycation end products (RAGE), thereby facilitating tumor growth and metastasis. Despite its importance in sustaining inflammation, the structural basis for RAGE-S100 crosstalk is still unknown. Here we report two crystal structures of the RAGE:S100A6 complex encompassing a full-length RAGE ectodomain. The structures, in combination with a comprehensive interaction analysis, suggest that the primary S100A6 binding site is formed by the RAGE C1 domain. Complex formation with S100A6 induces a unique dimeric conformation of RAGE that appears suited for signal transduction and intracellular effector recruitment. Intriguingly, S100A6 adopts a dimeric conformation radically different from all known S100 dimers. We discuss the physiological relevance of this non-canonical homodimeric form in vivo.