Structural characterization of the receptor for advanced glycation end products reveals a two domain modular architecture

Abstract

The Receptor for Advanced Glycation End Products (RAGE) contains a single transmembrane helix, a small cytosolic domain, and an extracellular region (sRAGE) composed of three Ig-like domains (V, C1, C2). RAGE has been implicated in complications arising from diabetes and chronic inflammation and is widely thought to be a therapeutic target. In this dissertation, production of purified sRAGE and the five single and tandem domain constructs enabled biophysical and structural characterization. The results, including an x-ray crystal structure of VC1, show that the V and C1 domains form an integrated structural unit. In contrast, C2 is attached to VC1 by a flexible linker and is fully independent. Studies of the interaction with a known RAGE ligand, Ca2+-S100B, revealed a major contribution from the V domain but clearly defined contributions to binding from the C1 domain. The implications of these results are discussed with respect to models for sRAGE quaternary structure and RAGE signaling.