Visual arrestins are key players in photoreceptor signaling, governing the rate of signal shutoff and photoresponse recovery. Closely related non-visual arrestins orchestrate signaling and trafficking of hundreds of different G protein-coupled receptors expressed in virtually every eukaryotic cell. Here we propose to elucidate molecular mechanisms of arrestin function in photoreceptors, focusing on arrestin1 (a.k.a. "rod" arrestin), which is expressed at high level in both rods and cones. Using a combination of biochemical and biophysical methods we propose to determine the conformation of rhodopsin-bound arrestin and the shape of the arrestin-rhodopsin complex. This will allow us to understand how arrestin complexes with hyper- phosphorylated rhodopsin contribute to photoreceptor death in cases of retinitis pigmentosa associated with constitutive formation of these "aberrant" complexes. We propose to test whether arrestin preferentially interacts with monomeric or dimeric rhodopsin, thereby defining the stoichiometry of the biologically relevant arrestin-rhodopsin complex. Based on our studies of the mechanism of arrestin self-association, we propose to elucidate the biological role of this process in photoreceptor cells in mice by replacing wild type arrestin with self-association-impaired mutants that retain all other arrestin functions. Based on the success of our initial proof-of-principle experiments, where we showed that arrestin mutants with high affinity for light-activated unphosphorylated rhodopsin improve the survival and facilitate photoresponse recovery in rhodopsin phosphorylation-deficient rods, we propose to design new "enhanced" arrestins with better ability to compensate for the defects of rhodopsin phosphorylation in mouse models of congenital visual disorders. We believe that this "compensational" approach will have high therapeutic value in all inherited disorders caused by gain-of-function receptor mutants, where traditional gene replacement approaches, that cannot "silence" excessive signaling by a mutant receptor, are ineffective.
Visual arrestins are key players in photoreceptor signaling, governing the rate of signal shutoff and photoresponse recovery. Here we propose to elucidate molecular mechanisms of arrestin function, focusing on the arrestin interaction with rhodopsin, the conformation of rhodopsin-bound arrestin and the stoichiometry and shape of the arrestin-rhodopsin complex, as well as on the mechanism and biological role of arrestin self- association in photoreceptor cells. We propose to use this structural information to construct custom- designed arrestin proteins with high affinity for light-activated unphosphorylated rhodopsin and test the ability of these enhanced mutants to compensate for the defects of rhodopsin phosphorylation in mouse models of congenital visual disorders.
|Zhan, Xuanzhi; Stoy, Henriette; Kaoud, Tamer S et al. (2016) Peptide mini-scaffold facilitates JNK3 activation in cells. Sci Rep 6:21025|
|Gurevich, Eugenia V; Gainetdinov, Raul R; Gurevich, Vsevolod V (2016) G protein-coupled receptor kinases as regulators of dopamine receptor functions. Pharmacol Res 111:1-16|
|Li, Lingyong; Homan, Kristoff T; Vishnivetskiy, Sergey A et al. (2015) G Protein-coupled Receptor Kinases of the GRK4 Protein Subfamily Phosphorylate Inactive G Protein-coupled Receptors (GPCRs). J Biol Chem 290:10775-90|
|Berkowitz, Bruce A; Gorgis, Jawan; Patel, Ankit et al. (2015) Development of an MRI biomarker sensitive to tetrameric visual arrestin 1 and its reduction via light-evoked translocation in vivo. FASEB J 29:554-64|
|Chatterjee, Deep; Eckert, Carl Elias; Slavov, Chavdar et al. (2015) Influence of Arrestin on the Photodecay of Bovine Rhodopsin. Angew Chem Int Ed Engl 54:13555-60|
|Kang, Yanyong; Zhou, X Edward; Gao, Xiang et al. (2015) Crystal structure of rhodopsin bound to arrestin by femtosecond X-ray laser. Nature 523:561-7|
|Zhan, Xuanzhi; Kook, Seunghyi; Kaoud, Tamer S et al. (2015) Arrestin-3-Dependent Activation of c-Jun N-Terminal Kinases (JNKs). Curr Protoc Pharmacol 68:2.12.1-26|
|Stoy, Henriette; Gurevich, Vsevolod V (2015) How genetic errors in GPCRs affect their function: Possible therapeutic strategies. Genes Dis 2:108-132|
|Gurevich, E V; Gurevich, V V (2015) Beyond traditional pharmacology: new tools and approaches. Br J Pharmacol 172:3229-41|
|Cleghorn, Whitney M; Branch, Kevin M; Kook, Seunghyi et al. (2015) Arrestins regulate cell spreading and motility via focal adhesion dynamics. Mol Biol Cell 26:622-35|
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