title: Arrestin2/clathrin interaction is regulated by key N- and C-terminal regions in arrestin2.
abstract: The interaction of nonvisual arrestins with clathrin is an important step in mediating the endocytosis of cell surface receptors. Previous studies have shown that mutation of the clathrin-binding box in arrestin leads to severe defects in arrestin-mediated trafficking. However, little is known about how arrestin/clathrin interaction is regulated. Here we show that both the N- and C-terminal regions of arrestin2 function to inhibit basal interaction with clathrin. Truncation analysis revealed that clathrin binding increases as the C-tail of arrestin2 is shortened while site-directed mutagenesis identified Glu-404, Glu-405, and Glu-406 as being primarily responsible for this inhibition. Mutagenesis also identified Lys-4, Arg-7, Lys-10, and Lys-11 within the N-terminus as playing a key role in regulating clathrin binding. Based on similarities with visual arrestin, Lys-10 and Lys-11 likely function as phospho sensors in arrestin2 to initially discriminate the phosphorylation status of target receptors. Analysis of the arrestin2 structure reveals that Arg-7, Lys-10, and Lys-11 are in close proximity to Glu-389 and Asp-390, suggesting that these residues may form intramolecular interactions. In fact, simultaneous mutation of Glu-389 and Asp-390 also leads to enhanced clathrin binding. These results reveal that multiple intramolecular interactions coordinately regulate arrestin2 interaction with clathrin, highlighting this interaction as a critical step in regulating receptor trafficking.
authors: Department of Biochemistry and Molecular Biology, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
authors: Ronald C
authors: RC
authors: Kern
authors: Dong Soo
authors: DS
authors: Kang
authors: Jeffrey L
authors: JL
authors: Benovic
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019390:Arrestins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D002966:Clathrin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D004705:Endocytosis / Q000502:physiology; D006801:Humans; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D011487:Protein Conformation; D020033:Protein Isoforms / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D019390:Arrestins; D002966:Clathrin; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins