title: Few residues within an extensive binding interface drive receptor interaction and determine the specificity of arrestin proteins.
abstract: Arrestins bind active phosphorylated forms of G protein-coupled receptors, terminating G protein activation, orchestrating receptor trafficking, and redirecting signaling to alternative pathways. Visual arrestin-1 preferentially binds rhodopsin, whereas the two non-visual arrestins interact with hundreds of G protein-coupled receptor subtypes. Here we show that an extensive surface on the concave side of both arrestin-2 domains is involved in receptor binding. We also identified a small number of residues on the receptor binding surface of the N- and C-domains that largely determine the receptor specificity of arrestins. We show that alanine substitution of these residues blocks the binding of arrestin-1 to rhodopsin in vitro and of arrestin-2 and -3 to β2-adrenergic, M2 muscarinic cholinergic, and D2 dopamine receptors in intact cells, suggesting that these elements critically contribute to the energy of the interaction. Thus, in contrast to arrestin-1, where direct phosphate binding is crucial, the interaction of non-visual arrestins with their cognate receptors depends to a lesser extent on phosphate binding and more on the binding to non-phosphorylated receptor elements.
authors.affiliation: Department of Pharmacology, Vanderbilt University, Nashville, Tennessee 37232, USA.
authors.forename: Sergey A
authors.initials: SA
authors.lastname: Vishnivetskiy
authors.forename: Luis E
authors.initials: LE
authors.lastname: Gimenez
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Francis
authors.forename: Susan M
authors.initials: SM
authors.lastname: Hanson
authors.forename: Wayne L
authors.initials: WL
authors.lastname: Hubbell
authors.forename: Candice S
authors.initials: CS
authors.lastname: Klug
authors.forename: Vsevolod V
authors.initials: VV
authors.lastname: Gurevich
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D019393:Arrestin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D001665:Binding Sites / Q000502:physiology*; D002417:Cattle; D006801:Humans; D020125:Mutation, Missense; D010449:Peptide Mapping; D017434:Protein Structure, Tertiary; D043562:Receptors, G-Protein-Coupled / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism
chemical_list: D019393:Arrestin; D043562:Receptors, G-Protein-Coupled