Elucidation of inositol hexaphosphate and heparin interaction sites and conformational changes in arrestin-1 by solution nuclear magnetic resonance.

ABSTRACT: Arrestins specifically bind activated and phosphorylated G protein-coupled receptors and orchestrate both receptor trafficking and channel signaling through G protein-independent pathways via direct interactions with numerous nonreceptor partners. Here we report the first successful use of solution NMR in mapping the binding sites in arrestin-1 (visual arrestin) for two polyanionic compounds that mimic phosphorylated light-activated rhodopsin: inositol hexaphosphate (IP6) and heparin. This yielded an identification of residues involved in the binding with these ligands that was more complete than what has previously been feasible. IP6 and heparin appear to bind to the same site on arrestin-1, centered on a positively charged region in the N-domain. We present the first direct evidence that

SUBMITTER: Zhuang T 

PROVIDER: S-EPMC3074303 | biostudies-literature | 2010 Dec

REPOSITORIES: biostudies-literature