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Adhesion G protein-coupled receptors (adhesion GPCRs), as a member of the G protein-coupled receptors (GPCRs) superfamily, have gradually entered the field of vision of researchers. The structure, function, and involvement of adhesion GPCRs in cancer development have been discussed in a series of papers. Uterine Corpus Endometrial Carcinoma (UCEC) isa malignanttumorofendometrium epithelial, whichis alsooneofthemostcommonfemalereproductivesystemtumors, but there are few pieces of research related to adhesion GPCRs in UCEC.In the current study, the UALCAN, GEPIA, Kaplan-Meier Plotter, MethSurv, SurvivalMeth, cBioPortal, String, GeneMANIA, DAVID, TRRUST, and Timer databases were used to examine the expression patterns and probable roles of adhesion GPCR family in UCEC.The expression levels of ADGRC1, ADGRC3, ADGRE1, ADGRF1, ADGRF2, ADGRF3, ADGRF4, ADGRG1, ADGRG5, ADGRG7, and ADGRV1 were significantly elevated in UCEC tissues, and the expression of ADGRC3 and ADGRF1 was significantly correlated with the pathological stage of UCEC. In patients with UCEC, ADGRA3, ADGRB1, ADGRB2, ADGRB3, ADGRC3, ADGRD2, ADGRF1, ADGRF2, ADGRF4, ADGRG1, ADGRG2, ADGRG4, ADGRG6, ADGRG7, ADGRL1, ADGRL2, and ADGRL3 had played important roles in patients' overall survival (OS), with a high expression suggesting shorter OS; while high levels of ADGRC2, ADGRD2, ADGRG7, and ADGRL2 suggested lower relapse-freesurvival (RFS). Furthermore, the prognostic value of the adhesion GPCRs gene individual CpG, as well as DNA methylation, was also analyzed; however, DNA methylation profiling demonstrated no significant correlation between the methylation level of adhesion GPCRs and the prognosis. The neighbor gene interaction analysis and enrichment analysis were also implemented to detect the possible mechanism. In addition, we found a correlation between the adhesion GPCRs and immune infiltrating cells, and the Cox proportional risk model of adhesion GPCRs with six immune cells showed that ADGRA1, ADGRF1, and ADGRG3 were closely connected with the clinical manifestations of UCEC patients.The adhesion GPCRs, especially ADGRF1, might be used as immunotherapeutic targets and prognostic markers of UCEC.

Dopamine receptors, including D1- and D2-like receptors, are important therapeutic targets in a variety of neurological syndromes, as well as cardiovascular and kidney diseases. Here, we present five cryoelectron microscopy (cryo-EM) structures of the dopamine D1 receptor (DRD1) coupled to Gs heterotrimer in complex with three catechol-based agonists, a non-catechol agonist, and a positive allosteric modulator for endogenous dopamine. These structures revealed that a polar interaction network is essential for catecholamine-like agonist recognition, whereas specific motifs in the extended binding pocket were responsible for discriminating D1- from D2-like receptors. Moreover, allosteric binding at a distinct inner surface pocket improved the activity of DRD1 by stabilizing endogenous dopamine interaction at the orthosteric site. DRD1-Gs interface revealed key features that serve as determinants for G protein coupling. Together, our study provides a structural understanding of the ligand recognition, allosteric regulation, and G protein coupling mechanisms of DRD1.

Background and Purpose Cholecystokinin (CCK) is secreted by intestinal I cells and regulates important metabolic functions. In pancreatic islets, CCK controls beta cell functions primarily through CCK1 receptors, but the signalling pathways downstream of these receptors in pancreatic beta cells are not well defined. Experimental Approach Apoptosis in pancreatic beta cell apoptosis was evaluated using Hoechst-33342 staining, TUNEL assays and Annexin-V-FITC/PI staining. Insulin secretion and second messenger production were monitored using ELISAs. Protein and phospho-protein levels were determined by Western blotting. A glucose tolerance test was carried out to examine the functions of CCK-8s in streptozotocin-induced diabetic mice. Key Results The sulfated carboxy-terminal octapeptide CCK26-33 amide (CCK-8s) activated CCK1 receptors and induced accumulation of both IP3 and cAMP. Whereas Gq-PLC-IP3 signalling was required for the CCK-8s-induced insulin secretion under low-glucose conditions, Gs-PKA/Epac signalling contributed more strongly to the CCK-8s-mediated insulin secretion in high-glucose conditions. CCK-8s also promoted formation of the CCK1 receptor/β-arrestin-1 complex in pancreatic beta cells. Using β-arrestin-1 knockout mice, we demonstrated that β-arrestin-1 is a key mediator of both CCK-8s-mediated insulin secretion and of its the protective effect against apoptosis in pancreatic beta cells. The anti-apoptotic effects of β-arrestin-1 occurred through cytoplasmic late-phase ERK activation, which activates the 90-kDa ribosomal S6 kinase-phospho–Bcl-2-family protein pathway. Conclusions and Implications Knowledge of different CCK1 receptor-activated downstream signalling pathways in the regulation of distinct functions of pancreatic beta cells could be used to identify biased CCK1 receptor ligands for the development of new anti-diabetic drugs.

Luminal fluid reabsorption plays a fundamental role in male fertility. We demonstrated that the ubiquitous GPCR signaling proteins Gq and β-arrestin-1 are essential for fluid reabsorption because they mediate coupling between an orphan receptor ADGRG2 (GPR64) and the ion channel CFTR. A reduction in protein level or deficiency of ADGRG2, Gq or β-arrestin-1 in a mouse model led to an imbalance in pH homeostasis in the efferent ductules due to decreased constitutive CFTR currents. Efferent ductule dysfunction was rescued by the specific activation of another GPCR, AGTR2. Further mechanistic analysis revealed that β-arrestin-1 acts as a scaffold for ADGRG2/CFTR complex formation in apical membranes, whereas specific residues of ADGRG2 confer coupling specificity for different G protein subtypes, this specificity is critical for male fertility. Therefore, manipulation of the signaling components of the ADGRG2-Gq/β-arrestin-1/CFTR complex by small molecules may be an effective therapeutic strategy for male infertility.

The cadherin epidermal growth factor (EGF) laminin G (LAG) seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors, which are pivotal regulators of many biologic processes such as neuronal/endocrine cell differentiation, vessel valve formation, and the control of planar cell polarity during embryonic development. All three members of the CELSR family (CELSR1-3) have large ecto-domains that form homophilic interactions and encompass more than 2000 amino acids. Mutations in the ecto-domain or other gene locations of CELSRs are associated with neural tube defects and other diseases in humans. Celsr knockout (KO) animals have many developmental defects. Therefore, specific agonists or antagonists of CELSR members may have therapeutic potential. Although significant progress has been made regarding the functions and biochemical properties of CELSRs, our knowledge of these receptors is still lacking, especially considering that they are broadly distributed but have few characterized functions in a limited number of tissues. The dynamic activation and inactivation of CELSRs and the presence of endogenous ligands beyond homophilic interactions remain elusive, as do the regulatory mechanisms and downstream signaling of these receptors. Given this motivation, future studies with more advanced cell biology or biochemical tools, such as conditional KO mice, may provide further insights into the mechanisms underlying CELSR function, laying the foundation for the design of new CELSR-targeted therapeutic reagents. The cadherin EGF LAG seven-pass G-type receptors (CELSRs) are a special subgroup of adhesion G protein-coupled receptors (GPCRs), which have large ecto-domains that form homophilic interactions and encompass more than 2000 amino acids. Recent studies have revealed that CELSRs are pivotal regulators of many biological processes, such as neuronal/endocrine cell differentiation, vessel valve formation and the control of planar cell polarity during embryonic development.

The very large G protein-coupled receptor 1 (VLGR1) is a core component in inner ear hair cell development. Mutations in the vlgr1 gene cause Usher syndrome, the symptoms of which include congenital hearing loss and progressive retinitis pigmentosa. However, the mechanism of VLGR1-regulated intracellular signaling and its role in Usher syndrome remain elusive. Here, we show that VLGR1 is processed into two fragments after autocleavage at the G protein-coupled receptor proteolytic site. The cleaved VLGR1 β-subunit constitutively inhibited adenylate cyclase (AC) activity through Gαi coupling. Co-expression of the Gαiq chimera with the VLGR1 β-subunit changed its activity to the phospholipase C/nuclear factor of activated T cells signaling pathway, which demonstrates the Gαi protein coupling specificity of this subunit. An R6002A mutation in intracellular loop 2 of VLGR1 abolished Gαi coupling, but the pathogenic VLGR1 Y6236fsx1 mutant showed increased AC inhibition. Furthermore, overexpression of another Usher syndrome protein, PDZD7, decreased the AC inhibition of the VLGR1 β-subunit but showed no effect on the VLGR1 Y6236fsx1 mutant. Taken together, we identified an independent Gαi signaling pathway of the VLGR1 β-subunit and its regulatory mechanisms that may have a role in the development of Usher syndrome.

A new method based on high performance liquid chromatography-electrospray ionization time of flight-mass spectrometry (HPLC-ESI-TOF/MS) was developed for the rapid identification of active compounds in Styela clava and the development of its specific chromatograms. Samples were extracted by ultrasonic-assisted extraction, and the extraction conditions were optimized. The developed HPLC-ESI-TOF/MS method was used to identify the components in Styela clava extract, and a specific chromatogram based on HPLC analysis was established. Ten compounds in Styela clava extract have been primary identified by HPLC-ESI-TOF/MS on-line detection combined with literature review. The result of similarity evaluation for specific chromatograms indicated that the quality of different Styela clava samples was not entirely consistent. This method has the advantages of simple operation, rapid measurement and it is a powerful tool for identification of active components in Styela clava and its quality control.

Neural stem and progenitor cells (NSPCs) can be isolated from the fetal or adult brain and expanded in culture for potential use in basic research, drug discovery and cell therapy. In the present study, two culture systems have been commonly used to maintain and expand NSPCs isolated from mammalian CNS: neurosphere and adhesive substrate-bound monolayer culture. NSPCs were isolated from the neuroepithelium of E14 embryonic rat cerebral cortex and maintained and expanded on fibronectin substrates or within neurospheres in serum-free medium. Ultrastructural study under transmission electron microscope revealed similar characteristics of immature morphology of NSPCs in adherent and neurosphere cultures. NSPCs cultured on adherent substrates and within neurospheres shared the properties of self-renewal and multipotency, but little is known about proliferation capacity and passaging potential of adherent NSPCs compared to neurosphere culture. We found that the self-renewal capacity of NSPCs in adherent culture was higher than that in neurosphere culture in the P1 and P3 passages, and reduced after the P5 passage. At the same time, comparative analysis using BrdU incorporation and immunostaining for nestin indicated that NSPCs grew significantly faster in primary cultures on adherent substrates than within neurospheres. Whereas, NSPCs in adherent culture could not maintain such robust growth for more than 6 passages. The growth of NSPCs within neurospheres was slower than that in adherent culture, but increased steadily and could be maintained for more than 10 passages. These data provide useful information for large scale in vitro expansion of NSPCs required by potential drug screening and cell therapy.