Arrestin interaction with E3 ubiquitin ligases and deubiquitinases: functional and therapeutic implications
1Department of Medicine, Duke University Medical Center, Durham, NC, USA, sudha@receptor-biol.duke.edu.
Abstract:
Arrestins constitute a small family of four homologous adaptor proteins (arrestins 1-4), which were originally identified as inhibitors of signal transduction elicited by the seven-transmembrane G protein-coupled receptors. Currently arrestins (especially arrestin2 and arrestin3; also called β-arrestin1 and β-arrestin2) are known to be activators of cell signaling and modulators of endocytic trafficking. Arrestins mediate these effects by binding to not only diverse cell-surface receptors but also by associating with a variety of critical signaling molecules in different intracellular compartments. Thus, the functions of arrestins are multifaceted and demand interactions with a host of proteins and require an array of selective conformations. Furthermore, receptor ligands that specifically induce signaling via arrestins are being discovered and their physiological roles are emerging. Recent evidence suggests that the activity of arrestin is regulated in space and time by virtue of its dynamic association with specific enzymes of the ubiquitination pathway. Ubiquitin-dependent, arrestin-mediated signaling could serve as a potential platform for developing novel therapeutic strategies to target transmembrane signaling and physiological responses.
Insights
Arrestins, initially seen as signal inhibitors, are now known to activate cell signaling and traffic. Their dynamic interactions, regulated by ubiquitination, offer new therapeutic targets for transmembrane signaling.
Area of Science:
- Molecular Biology
- Cellular Signaling
- Protein Biochemistry
Background:
- Arrestins (arrestin 1-4) are adaptor proteins historically identified as inhibitors of G protein-coupled receptor (GPCR) signaling.
- Emerging roles highlight arrestins, particularly arrestin2 and arrestin3 (β-arrestin1 and β-arrestin2), as key activators of cellular signaling pathways.
- Arrestins interact with numerous cell-surface receptors and intracellular signaling molecules, mediating diverse cellular functions.
Purpose of the Study:
- To elucidate the multifaceted roles of arrestins in cellular signaling and protein trafficking.
- To explore the dynamic interactions of arrestins with various proteins and their conformational requirements.
- To investigate the emerging roles of arrestin-biased ligands and the regulation of arrestin activity.
Main Methods:
- The study integrates existing literature and recent findings on arrestin function.
- Analysis of arrestin interactions with diverse cell-surface receptors and signaling molecules.
- Examination of arrestin regulation by ubiquitination pathways and its implications.
Main Results:
- Arrestins are crucial mediators of both signal transduction and endocytic trafficking.
- Arrestin function is highly dependent on protein-protein interactions and conformational flexibility.
- Ubiquitin-dependent regulation of arrestin activity is a critical aspect of their spatiotemporal control.
Conclusions:
- Arrestins play complex, dual roles as both signal inhibitors and activators.
- The dynamic and regulated nature of arrestin interactions is central to their diverse functions.
- Ubiquitin-mediated arrestin signaling presents a promising avenue for developing novel therapeutic strategies targeting transmembrane signaling.
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