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Gurevich, E. V.

Publications and source records attributed to Gurevich, E. V..

4 recordsLinked to original sources

Arrestin-3 promotes locomotor sensitization to psychostimulants via JNK signaling in nucleus accumbens

Arrestins play key role in desensitization of G protein-coupled receptors. Direct signaling role of arrestins has also been documented. Two ubiquitously expressed arrestin isoforms, arrestin-2 and -3 (Arr3), perform similarly in receptor desensitization and share many signaling functions, enabling them to substitute for one another. However, certain signaling roles are specific to each isoform. Mice lacking Arr3 (A3KO) show blunted acute responsiveness to the locomotor stimulatory effect of amphetamine (AMPH). Here we demonstrate that AMPH- and cocaine-induced locomotion of A3KO mice is significantly reduced. This loss-of-function phenotype suggests that Arr3-mediated signaling contributes to the effect. Virus-driven expression of Arr3 in caudate-putamen of A3KO and wild type mice suppressed AMPH-induced locomotion. In contrast, restoration of Arr3 in nucleus accumbens rescued locomotor response. Thus, in caudate-putamen Arr3 participates in the desensitization of dopamine receptors, whereas Arr3-dependent signaling in nucleus accumbens underlies the molecular mechanism of the locomotor response and sensitization. Using monofunctional Arr3-derived peptides, we showed that in the nucleus accumbens Arr3 promoted drug-induced locomotor responses via facilitation of JNK3 activation.

neuroscience↗

Arrestin-3 scaffolds multiple MAP3Ks driving stress-induced JNK3 activation and cell death.

Non-visual arrestin-3 (a.k.a. {beta}-arrestin-2) functions as a scaffold facilitating the activation of c-Jun N-terminal kinases (JNKs), an important pathway regulating cell fate. Here, we demonstrate that arrestin-3 scaffolds not only previously identified ASK1, but facilitates signaling by several MAP3Ks, including ZAK, ZAK{beta}, MEKK1, and TAK1. We identified ZAK (sterile alpha motif and leucine zipper-containing kinase) as the predominant MAP3K mediating arrestin-3-dependent JNK3 signaling and chemotherapy drug-induced cell death in HEK293 cells. We also showed that a 16-residue-long arrestin-3-derived peptide binds ZAK and fulfills the scaffolding function of full-length arrestin-3, sensitizing cells to death induced by chemotherapy drugs. These findings demonstrate that arrestin-3 is a versatile facilitator of stress signaling and suggest that functional peptide mimics can be used therapeutically to facilitate drug-induced death of cancer cells.

cell biology↗

Arrestin-3-assisted activation of JNK3 mediates dopaminergic behavioral and signaling plasticity in vivo.

In rodents with unilateral ablation of the substantia nigra neurons supplying dopamine to the striatum, chronic treatment with the dopamine precursor L-DOPA or dopamine agonists induces a progressive increase of behavioral responses, a process known as behavioral sensitization. The sensitization is blunted in arrestin-3 knockout mice. Using virus-mediated gene delivery to the dopamine-depleted striatum of arrestin-3 knockout mice, we found that the restoration of arrestin-3 fully rescued behavioral sensitization, whereas its mutant defective in JNK activation did not. A 25-residue arrestin-3-derived peptide that facilitates JNK3 activation in cells, expressed ubiquitously or selectively in the direct pathway striatal neurons, fully rescued sensitization, whereas an inactive homologous arrestin-2-derived peptide did not. Behavioral rescue was accompanied by the restoration of JNK3 activity and of JNK-dependent phosphorylation of the transcription factor c-Jun in the dopamine-depleted striatum. Thus, arrestin-3-dependent JNK3 activation in direct pathway neurons is a critical element of the molecular mechanism underlying sensitization.

neuroscience↗

GPCR binding and JNK3 activation by arrestin-3 have different structural requirements

Arrestins bind active phosphorylated G protein-coupled receptors (GPCRs). Among the four mammalian subtypes, only arrestin-3 facilitates the activation of JNK3 in cells. In available structures, Lys-295 in the lariat loop of arrestin-3 and its homologue Lys-294 in arrestin-2 directly interact with the activator-attached phosphates. We compared the role of arrestin-3 conformational equilibrium and of Lys-295 in GPCR binding and JNK3 activation. Several mutants with enhanced ability to bind GPCRs showed much lower activity towards JNK3, whereas a mutant that does not bind GPCRs was more active. Subcellular distribution of mutants did not correlate with GPCR recruitment or JNK3 activation. Charge neutralization and reversal mutations of Lys-295 differentially affected receptor binding on different backgrounds, but had virtually no effect on JNK3 activation. Thus, GPCR binding and arrestin-3-assisted JNK3 activation have distinct structural requirements, suggesting that facilitation of JNK3 activation is the function of arrestin-3 that is not bound to a GPCR.

cell biology↗