Differential Affinities of Visual Arrestin, βArrestin1, and βArrestin2 for G Protein-coupled Receptors Delineate Two Major Classes of Receptors

Abstract

Visual arrestin, ␤arrestin1, and ␤arrestin2 comprise a family of intracellular proteins that desensitize G protein-coupled receptors (GPCRs). In addition, ␤arrestin1 and ␤arrestin2 target desensitized receptors to clathrincoated pits for endocytosis. Whether arrestins differ in their ability to interact with GPCRs in cells is not known. In this study, we visualize the interaction of arrestin family members with GPCRs in real time and in live cells using green fluorescent protein-tagged arrestins. In the absence of agonist, visual arrestin and ␤arrestin1 were found in both the cytoplasm and nucleus of HEK-293 cells, whereas ␤arrestin2 was found only in the cytoplasm. Analysis of agonist-mediated arrestin translocation to multiple GPCRs identified two major classes of receptors. Class A receptors (␤2 adrenergic receptor, mu opioid receptor, endothelin type A receptor, dopamine D1A receptor, and ␣1b adrenergic receptor) bound ␤arrestin2 with higher affinity than ␤arrestin1 and did not interact with visual arrestin. In contrast, class B receptors (angiotensin II type 1A receptor, neurotensin receptor 1, vasopressin V2 receptor, thyrotropin-releasing hormone receptor, and substance P receptor) bound both ␤arrestin isoforms with similar high affinities and also interacted with visual arrestin. Switching the carboxyl-terminal tails of class A and class B receptors completely reversed the affinity of each receptor for the visual and non-visual arrestins. In addition, exchanging the ␤arrestin1 and ␤arrestin2 carboxyl termini reversed their extent of binding to class A receptors as well as their subcellular distribution. These results reveal for the first time marked differences in the ability of arrestin family members to bind GPCRs at the plasma membrane. Moreover, they show that visual arrestin can interact in cells with GPCRs other than rhodopsin. These findings suggest that GPCR signaling may be differentially regulated depending on the cellular complement of arrestin isoforms and the ability of arrestins to interact with other cellular proteins.

A cluster of differentially expressed signal transduction genes identified by microarray analysis in a rat genetic model of alcoholism

“…16 This mechanism has been demonstrated for the alpha1b-and beta2-adrenergic receptors, muand delta-opioid receptors, the dopamine D1 receptor and cannabinoid CB1 receptor. 17,18 Upon ligand binding b-arrestin also recruits cAMP phosphodiesterase type IV to the recetor-adenylate cyclase complex. 19 Both mechanisms lead to receptor desensitization and cAP signal termination.…”

Differential β-arrestin2 requirements for constitutive and agonist-induced internalization of the CB1 cannabinoid receptor

“…Thus, BRET titration experiments were carried out between CB 1 R-mVenus and β-arr1-Rluc or β-arr2-Rluc. Furthermore, the mVenus-tagged β 2 -adrenoceptor and AT 1 angiotensin receptor (β 2 AR-mVenus and AT 1 R-mVenus, respectively) were also tested for their β-arrestin affinities in the same system, as these two receptors are prototypical class A and class B GPCRs, respectively (Oakley et al, 2000), and therefore their β-arrestin binding properties could be used as a reference in our experiments. As expected, BRET titration curves of β 2 AR-mVenus and AT 1 R-mVenus followed saturation kinetics with both β-arrestin isoforms after agonist stimulus.…”

“…it can only be detected at or near the plasma membrane. In contrast, class B GPCRs, such as the AT 1 angiotensin receptor, bind both β-arr1 and β-arr2 with relatively high affinity and form stable complexes with β-arrestins, so that β-arrestins remain bound to the receptor after internalization and can be detected on intracellular vesicles (Oakley et al, 2000).…”

Arrestins and two receptor kinases are upregulated in Parkinson's disease with dementia

“…In vitro data demonstrate that most GPCR subtypes can be phosphorylated by several GRKs [71,94] and bind both arrestins equally well [33,59,94]. Conversely, in vivo studies suggest that receptors may be preferentially phosphorylated by specific GRKs [26,44,45,57,95] and interact with specific arrestins [58,78]. Importantly, GPCRs phosphorylated by different GRKs may signal differently [54,92].…”