Structure of active β-arrestin-1 bound to a G-protein-coupled receptor phosphopeptide
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- 21 April 2013
- journal article
- research article
- Published by Springer Science and Business Media LLC in Nature
- Vol. 497 (7447), 137-141
- https://doi.org/10.1038/nature12120
Abstract
The crystal structure of β-arrestin-1 in complex with a fully phosphorylated 29-amino-acid carboxy-terminal peptide derived from the V2 vasopressin receptor is reported; the structure of the complex shows striking conformational differences in β-arrestin-1 when compared with its inactive conformation. Arrestin proteins are negative regulators of G-protein-coupled receptor (GPCR) function and also act as G-protein-independent signalling proteins. Before forming a high-affinity complex, arrestins must be activated, and two papers in this issue of Nature focus on the interaction between GCPRs and activated arrestin at the atomic scale. Yong Ju Kim et al. mimicked the initial activation step by truncating the carboxy terminus of arrestin to produce the naturally occurring splice variant called p44 and determined its crystal structure. This structure provides insight into the role of naturally occurring truncated arrestins in the visual system. Arun Shukla et al. present the structure of non-visual β-arrestin-1 in complex with an antibody fragment (Fab30) and a fully phosphorylated 29-amino-acid C-terminal peptide derived from a GPCR, the arginine vasopressin type 2 receptor. Taken together, these two studies reveal striking conformational changes associated with arrestin activation. The functions of G-protein-coupled receptors (GPCRs) are primarily mediated and modulated by three families of proteins: the heterotrimeric G proteins, the G-protein-coupled receptor kinases (GRKs) and the arrestins1. G proteins mediate activation of second-messenger-generating enzymes and other effectors, GRKs phosphorylate activated receptors2, and arrestins subsequently bind phosphorylated receptors and cause receptor desensitization3. Arrestins activated by interaction with phosphorylated receptors can also mediate G-protein-independent signalling by serving as adaptors to link receptors to numerous signalling pathways4. Despite their central role in regulation and signalling of GPCRs, a structural understanding of β-arrestin activation and interaction with GPCRs is still lacking. Here we report the crystal structure of β-arrestin-1 (also called arrestin-2) in complex with a fully phosphorylated 29-amino-acid carboxy-terminal peptide derived from the human V2 vasopressin receptor (V2Rpp). This peptide has previously been shown to functionally and conformationally activate β-arrestin-1 (ref. 5). To capture this active conformation, we used a conformationally selective synthetic antibody fragment (Fab30) that recognizes the phosphopeptide-activated state of β-arrestin-1. The structure of the β-arrestin-1–V2Rpp–Fab30 complex shows marked conformational differences in β-arrestin-1 compared to its inactive conformation. These include rotation of the amino- and carboxy-terminal domains relative to each other, and a major reorientation of the ‘lariat loop’ implicated in maintaining the inactive state of β-arrestin-1. These results reveal, at high resolution, a receptor-interacting interface on β-arrestin, and they indicate a potentially general molecular mechanism for activation of these multifunctional signalling and regulatory proteins.Keywords
This publication has 38 references indexed in Scilit:
- Conformation of receptor-bound visual arrestinProceedings of the National Academy of Sciences of the United States of America, 2012
- Distinct loops in arrestin differentially regulate ligand binding within the GPCR opsinNature Communications, 2012
- Allosteric control of ligand-binding affinity using engineered conformation-specific effector proteinsNature Structural & Molecular Biology, 2011
- Structure of a nanobody-stabilized active state of the β2 adrenoceptorNature, 2011
- Crystal structure of full-length KcsA in its closed conformationProceedings of the National Academy of Sciences of the United States of America, 2009
- Functional specialization of β-arrestin interactions revealed by proteomic analysisProceedings of the National Academy of Sciences of the United States of America, 2007
- Phasercrystallographic softwareJournal of Applied Crystallography, 2007
- Seven-transmembrane receptorsNature Reviews Molecular Cell Biology, 2002
- [20] Processing of X-ray diffraction data collected in oscillation modeMethods in Enzymology, 1997
- Dictionary of protein secondary structure: Pattern recognition of hydrogen‐bonded and geometrical featuresPeptide Science, 1983