Agonistic Antibodies Reveal the Function of GPR56 in Human Glioma U87-MG Cells

Ohta, Shigeyuki; Sakaguchi, Sayaka; Kobayashi, Yuki; Mizuno, Norikazu; Tago, Kenji; Itoh, Hiroshi

doi:10.1248/bpb.b14-00752

Cited by 27 publications

(27 citation statements)

References 26 publications

(35 reference statements)

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“…Agonistic antibodies directed to GPR56 have been reported but their mechanisms of action are not fully understood (Ohta et al, 2015, Yang et al, 2015). The lack of well-characterized agonists and antagonists has hampered mechanistic studies of GPR56 and other aGPCRs.…”

Section: Discussionmentioning

confidence: 99%

Structural Basis for Regulation of GPR56/ADGRG1 by Its Alternatively Spliced Extracellular Domains

Salzman¹,

Ackerman

Ding

et al. 2016

Neuron

102

188

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Summary Adhesion G-protein-coupled receptors (aGPCRs) play critical roles in diverse neurobiological processes including brain development, synaptogenesis, and myelination. aGPCRs have large alternatively spliced extracellular regions (ECRs) that likely mediate intercellular signaling; however, the precise roles of ECRs remain unclear. The aGPCR GPR56/ADGRG1 regulates both oligodendrocyte and cortical development. Accordingly, human GPR56 mutations cause myelination defects and brain malformations. Here, we determined the crystal structure of the GPR56 ECR, the first structure of any complete aGPCR ECR, in complex with an inverse-agonist monobody, revealing a GPCR-Autoproteolysis-Inducing domain and a previously unidentified domain that we term Pentraxin/Laminin/neurexin/sex-hormone-binding-globulin-Like (PLL). Strikingly, PLL domain deletion caused increased signaling and characterizes a GPR56 splice variant. Finally, we show that an evolutionarily conserved residue in the PLL domain is critical for oligodendrocyte development in vivo. Thus, our results suggest that the GPR56 ECR has unique and multifaceted regulatory functions, providing novel insights into aGPCR roles in neurobiology.

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Section: Discussionmentioning

confidence: 99%

Structural Basis for Regulation of GPR56/ADGRG1 by Its Alternatively Spliced Extracellular Domains

Salzman¹,

Ackerman

Ding

et al. 2016

Neuron

102

188

View full text Add to dashboard Cite

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“…The powerful combination of ECR-targeted synthetic proteins, including monobodies and antibodies (35,40,51), with 7TM-targeted small molecule ligands will be invaluable in future mechanistic and pharmacological studies of aGPCRs.…”

Section: Discussionmentioning

confidence: 99%

“…Although it has been proposed that natural ligands may induce shedding on binding to N-terminal adhesion domains and thereby, activate the receptor, direct proof of ligand-induced shedding remains elusive. Several recent observations, including that some aGPCRs do not undergo autoproteolysis and therefore, cannot undergo shedding (20,34), have necessitated the introduction of a model, in which the ECR (i.e., associated NTF and Stachel) has a direct role in modulating the 7TM signaling (22,33,35,36). Regulation by this mechanism, which we term "Stachel-independent," is independent of Stachel-mediated activation, although the Stachel residues are present within the core of the GAIN domain (Fig.…”

mentioning

confidence: 99%

Stachel -independent modulation of GPR56/ADGRG1 signaling by synthetic ligands directed to its extracellular region

Salzman

Zhang

Gupta

et al. 2017

Proc. Natl. Acad. Sci. U.S.A.

105

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Adhesion G protein-coupled receptors (aGPCRs) play critical roles in diverse biological processes, including neurodevelopment and cancer progression. aGPCRs are characterized by large and diverse extracellular regions (ECRs) that are autoproteolytically cleaved from their membrane-embedded signaling domains. Although ECRs regulate receptor function, it is not clear whether ECRs play a direct regulatory role in G-protein signaling or simply serve as a protective cap for the activating "Stachel" sequence. Here, we present a mechanistic analysis of ECR-mediated regulation of GPR56/ADGRG1, an aGPCR with two domains [pentraxin and laminin/neurexin/sex hormonebinding globulin-like (PLL) and G protein-coupled receptor autoproteolysis-inducing (GAIN)] in its ECR. We generated a panel of high-affinity monobodies directed to each of these domains, from which we identified activators and inhibitors of GPR56-mediated signaling. Surprisingly, these synthetic ligands modulated signaling of a GPR56 mutant defective in autoproteolysis and hence, in Stachel peptide exposure. These results provide compelling support for a ligandinduced and ECR-mediated mechanism that regulates aGPCR signaling in a transient and reversible manner, which occurs in addition to the Stachel-mediated activation.adhesion GPCR | allostery | cell signaling | monobody | protein engineering

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“…The integrated transcriptome data of the genes located in the amplified region revealed the same trend except for three genes (NUP93, HERPUD1 and CIAPIN1). In the rest of the amplified genes, resulted by CNV analysis, we identified two gene families involved in glioblastoma such as MT1M and GPR56 [ 21 , 58 ]. Thanks to the transcriptome data, we could confirm that the differences in MT1M and GPR56 gene amplification matched the gene expression level between the S and L groups.…”

Section: Resultsmentioning

confidence: 99%

Cancer astrocytes have a more conserved molecular status in long recurrence free survival (RFS) IDH1 wild-type glioblastoma patients: new emerging cancer players

et al. 2018

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Glioblastoma is a devastating disease that despite all the information gathered so far, its optimal management remains elusive due to the absence of validated targets from clinical studies. A better clarification of the molecular mechanisms is needed. In this study, having access to IDH1 wild-type glioblastoma of patients with exceptionally long recurrence free survival (RFS), we decided to compare their mutational and gene expression profile to groups of IDH1 wild-type glioblastoma of patients with shorter RFS, by using NGS technology. The exome analysis revealed that Long-RFS tumors have a lower mutational rate compared to the other groups. A total of 158 genes were found differentially expressed among the groups, 112 of which distinguished the two RFS extreme groups. Overall, the exome data suggests that shorter RFS tumors could be, chronologically, in a more advanced state in the muli-step tumor process of sequential accumulation of mutations. New players in this kind of cancer emerge from the analysis, confirmed at the RNA/DNA level, identifying, therefore, possible oncodrivers or tumor suppressor genes.

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Agonistic Antibodies Reveal the Function of GPR56 in Human Glioma U87-MG Cells

Cited by 27 publications

References 26 publications

Structural Basis for Regulation of GPR56/ADGRG1 by Its Alternatively Spliced Extracellular Domains

Structural Basis for Regulation of GPR56/ADGRG1 by Its Alternatively Spliced Extracellular Domains

Stachel -independent modulation of GPR56/ADGRG1 signaling by synthetic ligands directed to its extracellular region

Cancer astrocytes have a more conserved molecular status in long recurrence free survival (RFS) IDH1 wild-type glioblastoma patients: new emerging cancer players

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