Kinetics, binding constant, and activation energy of the 48-kDa protein-rhodopsin complex by extra-metarhodopsin II

Schleicher, Andreas; Kuehn, Hermann; Hofmann, Klaus Peter

doi:10.1021/bi00430a052

Cited by 200 publications

(217 citation statements)

References 31 publications

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“…Interpreted in the context of the crystal structure, this model predicts that stabilizing intramolecular interactions are sequentially broken by an active phosphoreceptor, which allows arrestin to undergo the significant conformational rearrangement necessary for its transition into a high affinity receptor binding state (19,24). In the case of visual arrestin, this prediction was corroborated by extensive structure-based mutagenesis (15,25).…”

Section: Discussionmentioning

confidence: 96%

Conservation of the Phosphate-sensitive Elements in the Arrestin Family of Proteins

Celver¹,

Vishnivetskiy²,

Chavkin³

et al. 2002

Journal of Biological Chemistry

130

188

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Arrestins play a key role in the homologous desensitization of G protein-coupled receptors (GPCRs). These cytosolic proteins selectively bind to the agonist-activated and GPCR kinase-phosphorylated forms of the GPCR, precluding its further interaction with the G protein. Certain mutations in visual arrestin yield "constitutively active" proteins that bind with high affinity to the light-activated form of rhodopsin without requiring phosphorylation. The crystal structure of visual arrestin shows that these activating mutations perturb two groups of intramolecular interactions that keep arrestin in its basal (inactive) state. Here we introduced homologous mutations into arrestin2 and arrestin3 and found that the resulting mutants bind to the ␤ 2 -adrenoreceptor in vitro in a phosphorylation-independent fashion. The same mutants effectively desensitize both the ␤ 2 -adrenergic and ␦-opioid receptors in the absence of receptor phosphorylation in Xenopus oocytes. Moreover, the arrestin mutants also desensitize the truncated ␦-opioid receptor from which the C terminus, containing critical phosphorylation sites, has been removed. Conservation of the phosphate-sensitive hot spots in nonvisual arrestins suggests that the overall fold is similar to that of visual arrestin and that the mechanisms whereby receptor-attached phosphates drive arrestin transition into the active binding competent state are conserved throughout the arrestin family of proteins.Signaling by various members of the superfamily of G protein-coupled receptors (GPCRs) 1 is attenuated by a uniform two-step mechanism (1). First, the agonist-activated receptor that catalyzes GDP/GTP exchange on G proteins is specifically phosphorylated by a G protein-coupled receptor kinase (GRK). An arrestin protein then binds to the active phosphoreceptor, which makes further G protein interaction impossible by simple steric exclusion (2). Because of the high affinity of nonvisual arrestins 2 for various components of the trafficking machinery (3-5), the arrestin-receptor complex is then internalized. Arrestin binding also serves to switch GPCR signaling from G proteins to various mitogen-activated protein kinases (6 -8). The loss of active receptor conformation in the endosomes (presumably due to ligand dissociation) facilitates arrestin dissociation, rendering the phosphoreceptor accessible to protein phosphatases. The dephosphorylated receptor can then be recycled back to the plasma membrane (9).Perfectly timed binding and dissociation of arrestins, which are ensured by their remarkable selectivity for the phosphorylated/activated form of their cognate receptors, are equally important for high fidelity of this quenching mechanism. Destabilization of certain intramolecular interactions that support the basal (inactive) arrestin conformation by the activated phosphoreceptor is the mechanistic basis of arrestin selectivity (10,15,19,20). The visual arrestin residues involved in the stabilization of its basal state have been identified by extensive mutagenesis (10 -15,...

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Section: Discussionmentioning

confidence: 96%

Conservation of the Phosphate-sensitive Elements in the Arrestin Family of Proteins

Celver¹,

Vishnivetskiy²,

Chavkin³

et al. 2002

Journal of Biological Chemistry

130

188

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“…The current model for the understanding of the arrestinreceptor interaction mechanism is based on various studies of visual arrestin interaction with rhodopsin (11)(12)(13)(14)(15)(16). Visual arrestin binding with rhodopsin requires GRK-1 phosphorylated residues, and the contact of phosphorylated residues with a cationic region of arrestin switches it into an active conformation, enabling interaction with an exposed binding site on activated rhodopsin.…”

Section: Agonist Binding To Most G Protein-coupled Receptorsmentioning

confidence: 99%

Internalization Determinants of the Parathyroid Hormone Receptor Differentially Regulate β-Arrestin/Receptor Association

Vilardaga

Krasel

Chauvin

et al. 2002

Journal of Biological Chemistry

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␤-Arrestins have been implicated in regulating internalization of the parathyroid hormone receptor (PTHR), but the structural features in the receptor required for this effect are unknown. In the present study performed in HEK-293 cells, we demonstrated that different topological domains of PTHR are implicated in agonist-dependent receptor internalization; truncation of the cytoplasmic tail (PTHR-TR), selective mutations of the cytoplasmic tail to remove the sites of parathyroid hormone (PTH)-stimulated phosphorylation (PTHR-PD), and mutations in the third transmembrane helix (N289A) or in the third cytoplasmic loop (K382A) resulted in a 30 -60% reduction in 125 I-PTH-related protein internalization. To better define the role of these internalization determinants, we have tested the ability of these mutant PTHRs to associate with ␤-arrestins by using three different methodological approaches: 1) ability of overexpression of ␤-arrestins to restore the internalization of 125 I-PTH-related protein for the mutant PTHRs; 2) visualization of PTH-mediated trafficking of ␤-arrestin1 and -2 fused to the green fluorescent protein with receptors by confocal microscopy; 3) quantification of ␤-arrestin1-green fluorescent protein translocation by Western blot. Our data reveal that the receptor' cytoplasmic tail contains determinants of ␤-arrestin interaction that are distinct from the phosphorylation sites and are sufficient for transient association of ␤-arrestin2, but stable association requires receptor phosphorylation. Determinants in the receptor's core (Asn-289 and Lys-382) appear to regulate internalization of the receptor/␤-arrestin complex toward early endocytic endosomes during the initial step of endocytosis.Agonist binding to most G protein-coupled receptors (GPCRs) 1 is quickly followed by the internalization of the agonist-receptor complex into endocytic vesicles. The model developed from studies of the ␤ 2 -adrenergic receptor views internalization as a process facilitated by binding of ␤-arrestin proteins to agonist-activated receptors after phosphorylation of the receptors by G protein-coupled receptor kinases (GRKs) (1, 2). Phosphorylation of GPCRs by GRKs is a prerequisite for the mobilization of cytosolic ␤-arrestins. Binding of ␤-arrestins to GRK-phosphorylated receptors results in the physical uncoupling of receptors from their cognate G proteins and terminates agonist-mediated signaling (3, 4). It was shown recently that ␤-arrestins bind clathrin, a major component of the clathrinbased endocytic machinery, with high affinity and serve as an adaptor that targets activated and phosphorylated receptors to clathrin-coated pits (5-7). In the case of the ␤ 2 -adrenergic receptor, receptor internalization is the consequence of the formation of a complex between ␤-arrestin2, the clathrin adaptor protein AP2, clathrin, and the activated receptor (8). Internalization has at least two outcomes: directing the receptor to a compartment where the phosphates are removed, allowing resensitization, and movement of the r...

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“…1) (4-7). Arrestin-1 was proposed to undergo a conformational rearrangement during the P-Rh* interaction that results in the release of the C-terminal sequence (C tail) (8, 9) but does not involve major secondary structure changes (8,10). Recent site-directed spin labeling (SDSL) studies identified specific parts of arrestin-1 engaged by different functional forms of rhodopsin and provided direct evidence of binding-induced conformational changes (11,12).…”

mentioning

confidence: 99%

Conformation of receptor-bound visual arrestin

Kim

Vishnivetskiy²,

Eps

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

107

174

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Arrestin-1 (visual arrestin) binds to light-activated phosphorylated rhodopsin (P-Rh*) to terminate G-protein signaling. To map conformational changes upon binding to the receptor, pairs of spin labels were introduced in arrestin-1 and double electron-electron resonance was used to monitor interspin distance changes upon P-Rh* binding. The results indicate that the relative position of the N and C domains remains largely unchanged, contrary to expectations of a "clam-shell" model. A loop implicated in P-Rh* binding that connects β-strands V and VI (the "finger loop," residues 67-79) moves toward the expected location of P-Rh* in the complex, but does not assume a fully extended conformation. A striking and unexpected movement of a loop containing residue 139 away from the adjacent finger loop is observed, which appears to facilitate P-Rh* binding. This change is accompanied by smaller movements of distal loops containing residues 157 and 344 at the tips of the N and C domains, which correspond to "plastic" regions of arrestin-1 that have distinct conformations in monomers of the crystal tetramer. Remarkably, the loops containing residues 139, 157, and 344 appear to have high flexibility in both free arrestin-1 and the P-Rh*complex.A rrestin was first discovered in the visual system as a protein that blocks ("arrests") the signaling of the prototypical G protein-coupled receptor (GPCR) rhodopsin (Rh) via specific binding to the phosphorylated activated form P-Rh* (1). Mammals express four arrestin subtypes: Arrestin-1 and -4 are specific for the visual system, whereas arrestin-2 and -3 are ubiquitous (2). [We use systematic names of arrestins: arrestin-1 (historic names S-antigen, 48-kDa protein, or visual or rod arrestin), arrestin-2 (β-arrestin or β-arrestin1), arrestin-3 (β-arrestin2 or hTHY-ARRX), and arrestin-4 (cone or X-arrestin).] The discovery of nonvisual arrestins (3) showed that phosphorylation followed by arrestin binding is a common mechanism of GPCR regulation. Crystal structures of all four arrestin subtypes in their basal state revealed similar topology: two cup-like domains linked by an interdomain hinge ( Fig. 1) (4-7). Arrestin-1 was proposed to undergo a conformational rearrangement during the P-Rh* interaction that results in the release of the C-terminal sequence (C tail) (8, 9) but does not involve major secondary structure changes (8, 10). Recent site-directed spin labeling (SDSL) studies identified specific parts of arrestin-1 engaged by different functional forms of rhodopsin and provided direct evidence of binding-induced conformational changes (11,12). A conformational change in the so-called finger loop (Fig. 1) implicated in P-Rh* recognition was also observed using NMR and fluorescence quenching (13,14). Arrestin-1 shows a remarkable selectivity for P-Rh*. Observed binding to inactive phosphorylated (P-Rh) or active unphosphorylated rhodopsin (Rh*) is usually less than 10% of the binding to P-Rh*, whereas its binding to inactive unphosphorylated rhodopsin (Rh) is barely detectable ...

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Kinetics, binding constant, and activation energy of the 48-kDa protein-rhodopsin complex by extra-metarhodopsin II

Cited by 200 publications

References 31 publications

Conservation of the Phosphate-sensitive Elements in the Arrestin Family of Proteins

Conservation of the Phosphate-sensitive Elements in the Arrestin Family of Proteins

Internalization Determinants of the Parathyroid Hormone Receptor Differentially Regulate β-Arrestin/Receptor Association

Conformation of receptor-bound visual arrestin

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