title: Structure of an arrestin2-clathrin complex reveals a novel clathrin binding domain that modulates receptor trafficking.
abstract: Non-visual arrestins play a pivotal role as adaptor proteins in regulating the signaling and trafficking of multiple classes of receptors. Although arrestin interaction with clathrin, AP-2, and phosphoinositides contributes to receptor trafficking, little is known about the configuration and dynamics of these interactions. Here, we identify a novel interface between arrestin2 and clathrin through x-ray diffraction analysis. The intrinsically disordered clathrin binding box of arrestin2 interacts with a groove between blades 1 and 2 in the clathrin beta-propeller domain, whereas an 8-amino acid splice loop found solely in the long isoform of arrestin2 (arrestin2L) interacts with a binding pocket formed by blades 4 and 5 in clathrin. The apposition of the two binding sites in arrestin2L suggests that they are exclusive and may function in higher order macromolecular structures. Biochemical analysis demonstrates direct binding of clathrin to the splice loop in arrestin2L, whereas functional analysis reveals that both binding domains contribute to the receptor-dependent redistribution of arrestin2L to clathrin-coated pits. Mutagenesis studies reveal that the clathrin binding motif in the splice loop is (L/I)(2)GXL. Taken together, these data provide a framework for understanding the dynamic interactions between arrestin2 and clathrin and reveal an essential role for this interaction in arrestin-mediated endocytosis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Kang
authors.forename: Ronald C
authors.initials: RC
authors.lastname: Kern
authors.forename: Manojkumar A
authors.initials: MA
authors.lastname: Puthenveedu
authors.forename: Mark
authors.initials: M
authors.lastname: von Zastrow
authors.forename: John C
authors.initials: JC
authors.lastname: Williams
authors.forename: Jeffrey L
authors.initials: JL
authors.lastname: Benovic
mesh_terms: D020816:Amino Acid Motifs; D000818:Animals; D019393:Arrestin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D002417:Cattle; D002966:Clathrin / Q000737:chemistry* / Q000235:genetics / Q000276:immunology; D004705:Endocytosis / Q000502:physiology; D046912:Multiprotein Complexes / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D016296:Mutagenesis; D011485:Protein Binding / Q000502:physiology; D020836:Protein Structure, Quaternary / Q000502:physiology; D017434:Protein Structure, Tertiary / Q000502:physiology; D021381:Protein Transport / Q000502:physiology; D013329:Structure-Activity Relationship
chemical_list: D019393:Arrestin; D002966:Clathrin; D046912:Multiprotein Complexes