-
Molecular Biology Reports Dec 2023Β-arrestins are intracellular scaffolding proteins that have multifaceted roles in different types of disorders. In this review article, we gave a summary about the... (Review)
Review
Β-arrestins are intracellular scaffolding proteins that have multifaceted roles in different types of disorders. In this review article, we gave a summary about the discovery, characterization and classification of these proteins and their intracellular functions. Moreover, this review article focused on the hepatic expression of β-arrestins and their hepatocellular distribution and function in each liver cell type. Also, we showed that β-arrestins are key regulators of distinct types of hepatic disorders. On the other hand, we addressed some important points that have never been studied before regarding the role of β-arrestins in certain types of hepatic disorders which needs more research efforts to cover.
Topics: Humans; beta-Arrestins; Arrestins; Signal Transduction; Liver Diseases; Proteins
PubMed: 37843713
DOI: 10.1007/s11033-023-08898-0 -
BioRxiv : the Preprint Server For... Jul 2023Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT receptor activation mediates psychedelic effects, prototypical psychedelics activate...
Serotonergic psychedelics possess considerable therapeutic potential. Although 5-HT receptor activation mediates psychedelic effects, prototypical psychedelics activate both 5-HT-Gq/11 and β-arrestin2 signaling, making their respective roles unclear. To elucidate this, we developed a series of 5-HT-selective ligands with varying Gq efficacies, including β-arrestin-biased ligands. We show that 5-HT-Gq but not 5-HT-β-arrestin2 efficacy predicts psychedelic potential, assessed using head-twitch response (HTR) magnitude in male mice. We further show that disrupting Gq-PLC signaling attenuates the HTR and a threshold level of Gq activation is required to induce psychedelic-like effects, consistent with the fact that certain 5-HT partial agonists (e.g., lisuride) are non-psychedelic. Understanding the role of 5-HT-Gq efficacy in psychedelic-like psychopharmacology permits rational development of non-psychedelic 5-HT agonists. We also demonstrate that β-arrestin-biased 5-HT receptor agonists induce receptor downregulation and tachyphylaxis, and have an anti-psychotic-like behavioral profile. Overall, 5-HT receptor signaling can be fine-tuned to generate ligands with properties distinct from classical psychedelics.
PubMed: 37577474
DOI: 10.1101/2023.07.29.551106 -
Frontiers in Molecular Biosciences 2023There is now evidence from multiple Phase II clinical trials that psychedelic drugs can exert long-lasting anxiolytic, anti-depressant, and anti-drug abuse (nicotine and...
There is now evidence from multiple Phase II clinical trials that psychedelic drugs can exert long-lasting anxiolytic, anti-depressant, and anti-drug abuse (nicotine and ethanol) effects in patients. Despite these benefits, the hallucinogenic actions of these drugs at the serotonin 2A receptor (5-HT2AR) limit their clinical use in diverse settings. Activation of the 5-HT2AR can stimulate both G protein and -arrestin (βArr) -mediated signaling. Lisuride is a G protein biased agonist at the 5-HT2AR and, unlike the structurally-related lysergic acid diethylamide (LSD), the drug does not typically produce hallucinations in normal subjects at routine doses. Here, we examined behavioral responses to lisuride, in wild-type (WT), βArr1-knockout (KO), and βArr2-KO mice. In the open field, lisuride reduced locomotor and rearing activities, but produced a U-shaped function for stereotypies in both βArr lines of mice. Locomotion was decreased overall in βArr1-KOs and βArr2-KOs relative to wild-type controls. Incidences of head twitches and retrograde walking to lisuride were low in all genotypes. Grooming was decreased in βArr1 mice, but was increased then decreased in βArr2 animals with lisuride. Serotonin syndrome-associated responses were present at all lisuride doses in WTs, but they were reduced especially in βArr2-KO mice. Prepulse inhibition (PPI) was unaffected in βArr2 mice, whereas 0.5 mg/kg lisuride disrupted PPI in βArr1 animals. The 5-HT2AR antagonist MDL100907 failed to restore PPI in βArr1 mice, whereas the dopamine D2/D3 antagonist raclopride normalized PPI in WTs but not in βArr1-KOs. Clozapine, SCH23390, and GR127935 restored PPI in both βArr1 genotypes. Using vesicular monoamine transporter 2 mice, lisuride reduced immobility times in tail suspension and promoted a preference for sucrose that lasted up to 2 days. Together, it appears βArr1 and βArr2 play minor roles in lisuride's actions on many behaviors, while this drug exerts anti-depressant drug-like responses without hallucinogenic-like activities.
PubMed: 37900918
DOI: 10.3389/fmolb.2023.1233743 -
Cell & Bioscience Nov 2023Tachykinins and their cognate receptors, neurokinin receptors (NKs) including NK1, NK2, and NK3 play vital roles in regulating various physiological processes including...
BACKGROUND
Tachykinins and their cognate receptors, neurokinin receptors (NKs) including NK1, NK2, and NK3 play vital roles in regulating various physiological processes including neurotransmission, nociception, inflammation, smooth muscle contractility, and stimulation of endocrine and exocrine gland secretion. Their abnormal expression has been reported to be associated with neurological disorders, inflammation, and cancer. Even though NKs are expressed in the same cells with their expression being inversely correlated in some conditions, there is no direct evidence to prove their interaction. Understanding the functional crosstalk between NKs in mediated downstream signaling and cellular responses may elucidate the roles of each receptor in pathophysiology.
RESULTS
In this study, we showed that NKs were co-expressed in some cells. However, different from NK3, which only forms homodimerization, we demonstrated a direct interaction between NK1 and NK2 at the protein level using co-immunoprecipitation and NanoBiT-based protein interaction analysis. Through heterodimerization, NK2 downregulated substance P-stimulated NK1 signals, such as intracellular Ca mobilization and ERK phosphorylation, by enhancing β-arrestin recruitment, even at the ligand concentration that could not activate NK2 itself or in the presence of NK1 specific antagonist, aprepitant. In A549 cells with receptors deleted and reconstituted, NK2 exerted a negative effect on substance P/NK1-mediated cell migration.
CONCLUSION
Our study has provided the first direct evidence of an interaction between NK1 and NK2, which highlights the functional relevance of their heterodimerization in cellular responses. Our findings demonstrated that through dimerization, NK2 exerts negative effects on downstream signaling and cellular response mediated by NK1. Moreover, this study has significant implications for understanding the complexity of GPCR dimerization and its effect on downstream signaling and cellular responses. Given the important roles of tachykinins and NKs in pathophysiology, these insights may provide clues for developing NKs-targeting drugs.
PubMed: 37968728
DOI: 10.1186/s13578-023-01165-6 -
Cell Reports May 2024The binding and function of β-arrestins are regulated by specific phosphorylation motifs present in G protein-coupled receptors (GPCRs). However, the exact arrangement...
The binding and function of β-arrestins are regulated by specific phosphorylation motifs present in G protein-coupled receptors (GPCRs). However, the exact arrangement of phosphorylated amino acids responsible for establishing a stable interaction remains unclear. We employ a 1D sequence convolution model trained on GPCRs with established β-arrestin-binding properties. With this approach, amino acid motifs characteristic of GPCRs that form stable interactions with β-arrestins can be identified, a pattern that we name "arreSTick." Intriguingly, the arreSTick pattern is also present in numerous non-receptor proteins. Using proximity biotinylation assay and mass spectrometry analysis, we demonstrate that the arreSTick motif controls the interaction between many non-receptor proteins and β-arrestin2. The HIV-1 Tat-specific factor 1 (HTSF1 or HTATSF1), a nuclear transcription factor, contains the arreSTick pattern, and its subcellular localization is influenced by β-arrestin2. Our findings unveil a broader role for β-arrestins in phosphorylation-dependent interactions, extending beyond GPCRs to encompass non-receptor proteins as well.
Topics: Phosphorylation; Humans; beta-Arrestins; Protein Binding; Amino Acid Motifs; HEK293 Cells; beta-Arrestin 2; Amino Acid Sequence; Protein Stability
PubMed: 38758647
DOI: 10.1016/j.celrep.2024.114241 -
Protein & Cell Feb 2024
Topics: beta-Arrestins; Receptor, Cannabinoid, CB1; Cryoelectron Microscopy
PubMed: 38102480
DOI: 10.1093/procel/pwad055 -
Biomolecules Oct 2023The D2 dopamine receptor (D2R) signals through both G proteins and β-arrestins to regulate important physiological processes, such as movement, reward circuitry,...
G Protein-Coupled Receptor Kinase 2 Selectively Enhances β-Arrestin Recruitment to the D Dopamine Receptor through Mechanisms That Are Independent of Receptor Phosphorylation.
The D2 dopamine receptor (D2R) signals through both G proteins and β-arrestins to regulate important physiological processes, such as movement, reward circuitry, emotion, and cognition. β-arrestins are believed to interact with G protein-coupled receptors (GPCRs) at the phosphorylated C-terminal tail or intracellular loops. GPCR kinases (GRKs) are the primary drivers of GPCR phosphorylation, and for many receptors, receptor phosphorylation is indispensable for β-arrestin recruitment. However, GRK-mediated receptor phosphorylation is not required for β-arrestin recruitment to the D2R, and the role of GRKs in D2R-β-arrestin interactions remains largely unexplored. In this study, we used GRK knockout cells engineered using CRISPR-Cas9 technology to determine the extent to which β-arrestin recruitment to the D2R is GRK-dependent. Genetic elimination of all GRK expression decreased, but did not eliminate, agonist-stimulated β-arrestin recruitment to the D2R or its subsequent internalization. However, these processes were rescued upon the re-introduction of various GRK isoforms in the cells with GRK2/3 also enhancing dopamine potency. Further, treatment with compound 101, a pharmacological inhibitor of GRK2/3 isoforms, decreased β-arrestin recruitment and receptor internalization, highlighting the importance of this GRK subfamily for D2R-β-arrestin interactions. These results were recapitulated using a phosphorylation-deficient D2R mutant, emphasizing that GRKs can enhance β-arrestin recruitment and activation independently of receptor phosphorylation.
Topics: Arrestins; beta-Arrestins; G-Protein-Coupled Receptor Kinases; Phosphorylation; Protein Isoforms; Receptors, Dopamine; Receptors, G-Protein-Coupled; Humans; HEK293 Cells
PubMed: 37892234
DOI: 10.3390/biom13101552 -
The role of G protein-coupled receptor kinases in GLP-1R β-arrestin recruitment and internalisation.Biochemical Pharmacology Apr 2024The glucagon-like peptide 1 receptor (GLP-1R) is a validated clinical target for the treatment of type 2 diabetes and obesity. Unlike most G protein-coupled receptors...
The glucagon-like peptide 1 receptor (GLP-1R) is a validated clinical target for the treatment of type 2 diabetes and obesity. Unlike most G protein-coupled receptors (GPCRs), the GLP-1R undergoes an atypical mode of internalisation that does not require β-arrestins. While differences in GLP-1R trafficking and β-arrestin recruitment have been observed between clinically used GLP-1R agonists, the role of G protein-coupled receptor kinases (GRKs) in affecting these pathways has not been comprehensively assessed. In this study, we quantified the contribution of GRKs to agonist-mediated GLP-1R internalisation and β-arrestin recruitment profiles using cells where endogenous β-arrestins, or non-visual GRKs were knocked out using CRISPR/Cas9 genome editing. Our results confirm the previously established atypical β-arrestin-independent mode of GLP-1R internalisation and revealed that GLP-1R internalisation is dependent on the expression of GRKs. Interestingly, agonist-mediated GLP-1R β-arrestin 1 and β-arrestin 2 recruitment were differentially affected by endogenous GRK knockout with β-arrestin 1 recruitment more sensitive to GRK knockout than β-arrestin 2 recruitment. Moreover, individual overexpression of GRK2, GRK3, GRK5 or GRK6 in a newly generated GRK2/3/4/5/6 HEK293 cells, rescued agonist-mediated β-arrestin 1 recruitment and internalisation profiles to similar levels, suggesting that there is no specific GRK isoform that drives these pathways. This study advances mechanistic understanding of agonist-mediated GLP-1R internalisation and provides novel insights into how GRKs may fine-tune GLP-1R signalling.
Topics: Humans; Arrestins; beta-Arrestin 1; beta-Arrestin 2; beta-Arrestins; Diabetes Mellitus, Type 2; G-Protein-Coupled Receptor Kinases; Glucagon-Like Peptide-1 Receptor; HEK293 Cells; Phosphorylation; Receptors, G-Protein-Coupled
PubMed: 38461904
DOI: 10.1016/j.bcp.2024.116119 -
Hypertension (Dallas, Tex. : 1979) Jan 2024β-arrestins are a family of intracellular signaling proteins that play a key role in regulating the activity of G protein-coupled receptors. The angiotensin-II type 1... (Review)
Review
β-arrestins are a family of intracellular signaling proteins that play a key role in regulating the activity of G protein-coupled receptors. The angiotensin-II type 1 receptor is an important G protein-coupled receptor involved in the regulation of cardiovascular function and has been implicated in the progression of cardiovascular diseases. In addition to canonical G protein signaling, G protein-coupled receptors including the angiotensin-II type 1 receptor can signal via β-arrestin. Dysregulation of β-arrestin signaling has been linked to several cardiovascular diseases including hypertension, atherosclerosis, and heart failure. Understanding the role of β-arrestins in these conditions is critical to provide new therapeutic targets for the treatment of cardiovascular disease. In this review, we will discuss the beneficial and maladaptive physiological outcomes of angiotensin-II type 1 receptor-dependent β-arrestin activation in different cardiovascular diseases.
Topics: Humans; beta-Arrestins; Cardiovascular Diseases; Arrestins; Signal Transduction; Receptor, Angiotensin, Type 1; Angiotensins; beta-Arrestin 2; beta-Arrestin 1; Angiotensin II
PubMed: 37449411
DOI: 10.1161/HYPERTENSIONAHA.123.19419 -
The Journal of Clinical Endocrinology... Oct 2023Lost glucagon-like peptide 1 receptor (GLP-1R) function affects human physiology.
CONTEXT
Lost glucagon-like peptide 1 receptor (GLP-1R) function affects human physiology.
OBJECTIVE
This work aimed to identify coding nonsynonymous GLP1R variants in Danish individuals to link their in vitro phenotypes and clinical phenotypic associations.
METHODS
We sequenced GLP1R in 8642 Danish individuals with type 2 diabetes or normal glucose tolerance and examined the ability of nonsynonymous variants to bind GLP-1 and to signal in transfected cells via cyclic adenosine monophosphate (cAMP) formation and β-arrestin recruitment. We performed a cross-sectional study between the burden of loss-of-signaling (LoS) variants and cardiometabolic phenotypes in 2930 patients with type 2 diabetes and 5712 participants in a population-based cohort. Furthermore, we studied the association between cardiometabolic phenotypes and the burden of the LoS variants and 60 partly overlapping predicted loss-of-function (pLoF) GLP1R variants found in 330 566 unrelated White exome-sequenced participants in the UK Biobank cohort.
RESULTS
We identified 36 nonsynonymous variants in GLP1R, of which 10 had a statistically significant loss in GLP-1-induced cAMP signaling compared to wild-type. However, no association was observed between the LoS variants and type 2 diabetes, although LoS variant carriers had a minor increased fasting plasma glucose level. Moreover, pLoF variants from the UK Biobank also did not reveal substantial cardiometabolic associations, despite a small effect on glycated hemoglobin A1c.
CONCLUSION
Since no homozygous LoS nor pLoF variants were identified and heterozygous carriers had similar cardiometabolic phenotype as noncarriers, we conclude that GLP-1R may be of particular importance in human physiology, due to a potential evolutionary intolerance of harmful homozygous GLP1R variants.
Topics: Humans; Diabetes Mellitus, Type 2; Glucagon-Like Peptide-1 Receptor; Cross-Sectional Studies; Glucagon-Like Peptide 1; Phenotype; Cardiovascular Diseases
PubMed: 37235780
DOI: 10.1210/clinem/dgad290