Antigen Design for Successful Isolation of Highly Challenging Therapeutic Anti-GPCR Antibodies

G-protein-coupled receptors (GPCR) transmit extracellular signals into cells to regulate a variety of cellular functions and are closely related to the homeostasis of the human body and the progression of various types of diseases. Great attention has been paid to GPCRs as excellent drug targets, and there are many commercially available small-molecule chemical drugs against GPCRs. Despite this, the development of therapeutic anti-GPCR antibodies has been delayed and is challenging due to the difficulty in preparing active forms of GPCR antigens, resulting from their low cellular expression and complex structures. Here, we focus on anti-GPCR antibodies that have been approved or are subject to clinical trials and present various technologies to prepare active GPCR antigens that enable the isolation of therapeutic antibodies to proceed toward clinical validation.

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Carbazole Derivatives as Kinase-Targeting Inhibitors for Cancer Treatment

Mini-Reviews in Medicinal Chemistry ◽

10.2174/1389557520666200117144701 ◽

2020 ◽

Vol 20 (6) ◽

pp. 444-465 ◽

Cited By ~ 1

Author(s):

Jessica Ceramella ◽

Domenico Iacopetta ◽

Alexia Barbarossa ◽

Anna Caruso ◽

Fedora Grande ◽

...

Keyword(s):

Cancer Progression ◽

Drug Targets ◽

Mechanisms Of Action ◽

Biological Pathways ◽

G Protein Coupled Receptors ◽

Ability To Act ◽

Different Types ◽

Activity Of Enzymes ◽

Intercalating Agents ◽

G Protein Coupled

Protein Kinases (PKs) are a heterogeneous family of enzymes that modulate several biological pathways, including cell division, cytoskeletal rearrangement, differentiation and apoptosis. In particular, due to their crucial role during human tumorigenesis and cancer progression, PKs are ideal targets for the design and development of effective and low toxic chemotherapeutics and represent the second group of drug targets after G-protein-coupled receptors. Nowadays, several compounds have been claimed to be PKs inhibitors, and some of them, such as imatinib, erlotinib and gefitinib, have already been approved for clinical use, whereas more than 30 others are in various phases of clinical trials. Among them, some natural or synthetic carbazole-based molecules represent promising PKs inhibitors due to their capability to interfere with PK activity by different mechanisms of action including the ability to act as DNA intercalating agents, interfere with the activity of enzymes involved in DNA duplication, such as topoisomerases and telomerases, and inhibit other proteins such as cyclindependent kinases or antagonize estrogen receptors. Thus, carbazoles can be considered a promising this class of compounds to be adopted in targeted therapy of different types of cancer.

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The relevance of adhesion G protein-coupled receptors in metabolic functions

Biological Chemistry ◽

10.1515/hsz-2021-0146 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Isabell Kaczmarek ◽

Tomáš Suchý ◽

Simone Prömel ◽

Torsten Schöneberg ◽

Ines Liebscher ◽

...

Keyword(s):

G Protein ◽

Drug Targets ◽

Metabolic Diseases ◽

Current Knowledge ◽

G Protein Coupled Receptors ◽

Specific Expression ◽

Physiological Functions ◽

Metabolic Functions ◽

Central Nervous Systems ◽

G Protein Coupled

Abstract G protein-coupled receptors (GPCRs) modulate a variety of physiological functions and have been proven to be outstanding drug targets. However, approximately one-third of all non-olfactory GPCRs are still orphans in respect to their signal transduction and physiological functions. Receptors of the class of Adhesion GPCRs (aGPCRs) are among these orphan receptors. They are characterized by unique features in their structure and tissue-specific expression, which yields them interesting candidates for deorphanization and testing as potential therapeutic targets. Capable of G-protein coupling and non-G protein-mediated function, aGPCRs may extend our repertoire of influencing physiological function. Besides their described significance in the immune and central nervous systems, growing evidence indicates a high importance of these receptors in metabolic tissue. RNAseq analyses revealed high expression of several aGPCRs in pancreatic islets, adipose tissue, liver, and intestine but also in neurons governing food intake. In this review, we focus on aGPCRs and their function in regulating metabolic pathways. Based on current knowledge, this receptor class represents high potential for future pharmacological approaches addressing obesity and other metabolic diseases.

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Compartmentalization of GPCR signalling controls unique cellular responses

Biochemical Society Transactions ◽

10.1042/bst20150236 ◽

2016 ◽

Vol 44 (2) ◽

pp. 562-567 ◽

Cited By ~ 27

Author(s):

Andrew M. Ellisdon ◽

Michelle L. Halls

Keyword(s):

Drug Discovery ◽

Drug Targets ◽

Cell Types ◽

G Protein Coupled Receptors ◽

Attrition Rates ◽

Physiological Processes ◽

Simple Chain ◽

G Protein Coupled ◽

Major Drug ◽

Very High

With >800 members, G protein-coupled receptors (GPCRs) are the largest class of cell-surface signalling proteins, and their activation mediates diverse physiological processes. GPCRs are ubiquitously distributed across all cell types, involved in many diseases and are major drug targets. However, GPCR drug discovery is still characterized by very high attrition rates. New avenues for GPCR drug discovery may be provided by a recent shift away from the traditional view of signal transduction as a simple chain of events initiated from the plasma membrane. It is now apparent that GPCR signalling is restricted to highly organized compartments within the cell, and that GPCRs activate distinct signalling pathways once internalized. A high-resolution understanding of how compartmentalized signalling is controlled will probably provide unique opportunities to selectively and therapeutically target GPCRs.

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Natural polyamines stimulate G-proteins

Biochemical Journal ◽

10.1042/bj2820545 ◽

1992 ◽

Vol 282 (2) ◽

pp. 545-550 ◽

Cited By ~ 64

Author(s):

J L Bueb ◽

A Da Silva ◽

M Mousli ◽

Y Landry

Keyword(s):

Mast Cells ◽

Pertussis Toxin ◽

Inositol Phosphates ◽

Second Messengers ◽

G Protein Coupled Receptors ◽

Extracellular Signals ◽

Physiological Relevance ◽

G Protein Coupled ◽

Stimulation Of ◽

Rat Mast Cells

The natural polyamines spermine and spermidine, the biosynthetic precursor putrescine and their analogues cadaverine and tyramine stimulate the GTPase activity of purified GTP-binding proteins (Go/Gi) from calf brain reconstituted into phospholipid vesicles. The order of potency was spermine greater than spermidine greater than putrescine = cadaverine greater than tyramine. The physiological relevance of this observation was assessed, showing the same order of potency of polyamines in the stimulation of peritoneal and tracheal rat mast cells. The activation of rat mast cells by polyamines was inhibited by benzalkonium chloride or by a 2 h pretreatment of the cells with pertussis toxin. The increase in inositol phosphates evoked by polyamines was also inhibited by pertussis toxin. Therefore we propose that intracellular polyamines might control the basal level of second messengers and modulate extracellular signals transduced through G-protein-coupled receptors.

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G Protein‐Coupled Receptors as Drug Targets

10.1002/352760734x ◽

2005 ◽

Cited By ~ 2

Keyword(s):

G Protein ◽

Drug Targets ◽

G Protein Coupled Receptors ◽

G Protein Coupled

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Identification of the C3a Receptor (C3AR1) as the Target of the VGF-derived Peptide TLQP-21 in Rodent Cells

Journal of Biological Chemistry ◽

10.1074/jbc.m113.497214 ◽

2013 ◽

Vol 288 (38) ◽

pp. 27434-27443 ◽

Cited By ~ 59

Author(s):

Sebastien Hannedouche ◽

Valerie Beck ◽

Juliet Leighton-Davies ◽

Martin Beibel ◽

Guglielmo Roma ◽

...

Keyword(s):

G Protein ◽

Cellular Response ◽

G Protein Coupled Receptors ◽

Proteolytic Processing ◽

Rodent Models ◽

Cellular Functions ◽

Genome Wide ◽

Response To Stress ◽

G Protein Coupled ◽

Human Receptor

TLQP-21, a peptide derived from VGF (non-acronymic) by proteolytic processing, has been shown to modulate energy metabolism, differentiation, and cellular response to stress. Although extensively investigated, the receptor for this endogenous peptide has not previously been described. This study describes the use of a series of studies that show G protein-coupled receptor-mediated biological activity of TLQP-21 signaling in CHO-K1 cells. Unbiased genome-wide sequencing of the transcriptome from responsive CHO-K1 cells identified a prioritized list of possible G protein-coupled receptors bringing about this activity. Further experiments using a series of defined receptor antagonists and siRNAs led to the identification of complement C3a receptor-1 (C3AR1) as a target for TLQP-21 in rodents. We have not been able to demonstrate so far that this finding is translatable to the human receptor. Our results are in line with a large number of physiological observations in rodent models of food intake and metabolic control, where TLQP-21 shows activity. In addition, the sensitivity of TLQP-21 signaling to pertussis toxin is consistent with the known signaling pathway of C3AR1. The binding of TLQP-21 to C3AR1 not only has effects on signaling but also modulates cellular functions, as TLQP-21 was shown to have a role in directing migration of mouse RAW264.7 cells.

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Beyond the Flavour: The Potential Druggability of Chemosensory G Protein-Coupled Receptors

International Journal of Molecular Sciences ◽

10.3390/ijms20061402 ◽

2019 ◽

Vol 20 (6) ◽

pp. 1402 ◽

Cited By ~ 15

Author(s):

Antonella Di Pizio ◽

Maik Behrens ◽

Dietmar Krautwurst

Keyword(s):

G Protein ◽

Drug Targets ◽

Current Knowledge ◽

Chemical Space ◽

G Protein Coupled Receptors ◽

The Body ◽

Odorant Receptors ◽

Taste Receptors ◽

Umami Taste ◽

G Protein Coupled

G protein-coupled receptors (GPCRs) belong to the largest class of drug targets. Approximately half of the members of the human GPCR superfamily are chemosensory receptors, including odorant receptors (ORs), trace amine-associated receptors (TAARs), bitter taste receptors (TAS2Rs), sweet and umami taste receptors (TAS1Rs). Interestingly, these chemosensory GPCRs (csGPCRs) are expressed in several tissues of the body where they are supposed to play a role in biological functions other than chemosensation. Despite their abundance and physiological/pathological relevance, the druggability of csGPCRs has been suggested but not fully characterized. Here, we aim to explore the potential of targeting csGPCRs to treat diseases by reviewing the current knowledge of csGPCRs expressed throughout the body and by analysing the chemical space and the drug-likeness of flavour molecules.

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G-Protein-Coupled Receptors in Drug Discovery: Nanosizing Using Cell-Free Technologies and Molecular Biology Approaches

CrossRef Listing of Deleted DOIs ◽

10.1177/1087057105280517 ◽

2005 ◽

Vol 10 (8) ◽

pp. 765-779 ◽

Cited By ~ 30

Author(s):

Wayne R. Leifert ◽

Amanda L. Aloia ◽

Olgatina Bucco ◽

Richard V. Glatz ◽

Edward J. McMurchie

Keyword(s):

Signal Transduction ◽

G Protein ◽

Drug Targets ◽

G Protein Coupled Receptors ◽

Orphan Receptors ◽

Molecular Switching ◽

Physiological Processes ◽

Current Cell ◽

G Protein Coupled ◽

Signaling Components

Signal transduction by G-protein-coupled receptors (GPCRs) underpins a multitude of physiological processes. Ligand recognition by the receptor leads to activation of a genericmolecular switch involving heterotrimeric G-proteins and guanine nucleotides. Signal transduction has been studied extensively with both cell-based systems and assays comprising isolated signaling components. Interest and commercial investment in GPCRs in areas such as drug targets, orphan receptors, highthroughput screening, biosensors, and so on will focus greater attention on assay development to allow for miniaturization, ultra-high throughput and, eventually, microarray/biochip assay formats. Although cell-based assays are adequate for many GPCRs, it is likely that these formatswill limit the development of higher density GPCRassay platforms mandatory for other applications. Stable, robust, cell-free signaling assemblies comprising receptor and appropriate molecular switching components will form the basis of future GPCR assay platforms adaptable for such applications as microarrays. The authors review current cell-free GPCR assay technologies and molecular biological approaches for construction of novel, functional GPCR assays.

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ADAMs as mediators of EGF receptor transactivation by G protein-coupled receptors

AJP Cell Physiology ◽

10.1152/ajpcell.00620.2005 ◽

2006 ◽

Vol 291 (1) ◽

pp. C1-C10 ◽

Cited By ~ 235

Author(s):

Haruhiko Ohtsu ◽

Peter J. Dempsey ◽

Satoru Eguchi

Keyword(s):

G Protein ◽

Egf Receptor ◽

Current Knowledge ◽

G Protein Coupled Receptors ◽

Surface Proteins ◽

Egf Receptors ◽

Cellular Functions ◽

Egfr Transactivation ◽

And Migration ◽

G Protein Coupled

A disintegrin and metalloprotease (ADAM) is a membrane-anchored metalloprotease implicated in the ectodomain shedding of cell surface proteins, including the ligands for epidermal growth factor (EGF) receptors (EGFR)/ErbB. It has been well documented that the transactivation of the EGFR plays critical roles for many cellular functions, such as proliferation and migration mediated through multiple G protein-coupled receptors (GPCRs). Recent accumulating evidence has suggested that ADAMs are the key metalloproteases activated by several GPCR agonists to produce a mature EGFR ligand leading to the EGFR transactivation. In this review, we describe the current knowledge on ADAMs implicated in mediating EGFR transactivation. The major focus of the review will be on the possible upstream mechanisms of ADAM activation by GPCRs as well as downstream signal transduction and the pathophysiological significances of ADAM-dependent EGFR transactivation.

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