| 1. |
- Kotliar, Ilana B., et al.
(författare)
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Itch receptor MRGPRX4 interacts with the receptor activity-modifying proteins
- 2023
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Ingår i: Journal of Biological Chemistry. - : Elsevier BV. - 0021-9258 .- 1083-351X. ; 299:5
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Tidskriftsartikel (refereegranskat)abstract
- Cholestatic itch is a severe and debilitating symptom in liver diseases with limited treatment options. The class A G proteincoupled receptor (GPCR) Mas-related GPCR subtype X4 (MRGPRX4) has been identified as a receptor for bile acids, which are potential cholestatic pruritogens. An increasing number of GPCRs have been shown to interact with receptor activity-modifying proteins (RAMPs), which can modulate different aspects of GPCR biology. Using a combination of multiplexed immunoassay and proximity ligation assay, we show that MRGPRX4 interacts with RAMPs. The interaction of MRGPRX4 with RAMP2, but not RAMP1 or 3, causes attenuation of basal and agonist-dependent signaling, which correlates with a decrease of MRGPRX4 cell surface expression as measured using a quantitative NanoBRET pulse-chase assay. Finally, we use AlphaFold Multimer to predict the structure of the MRGPRX4-RAMP2 complex. The discovery that RAMP2 regulates MRGPRX4 may have direct implications for future drug development for cholestatic itch.
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| 2. |
- Lorenzen, Emily, et al.
(författare)
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Multiplexed analysis of the secretin-like GPCR-RAMP interactome
- 2019
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Ingår i: Science Advances. - : AMER ASSOC ADVANCEMENT SCIENCE. - 2375-2548. ; 5:9
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Tidskriftsartikel (refereegranskat)abstract
- Receptor activity-modifying proteins (RAMPs) have been shown to modulate the functions of several G protein-coupled receptors (GPCRs), but potential direct interactions among the three known RAMPs and hundreds of GPCRs have never been investigated. Focusing mainly on the secretin-like family of GPCRs, we engineered epitope-tagged GPCRs and RAMPs, and developed a multiplexed suspension bead array (SBA) immunoassay to detect GPCR-RAMP complexes from detergent-solubilized lysates. Using 64 antibodies raised against the native proteins and 4 antibodies targeting the epitope tags, we mapped the interactions among 23 GPCRs and 3 RAMPs. We validated nearly all previously reported secretin-like GPCR-RAMP interactions, and also found previously unidentified RAMP interactions with additional secretin-like GPCRs, chemokine receptors, and orphan receptors. The results provide a complete interactome of secretin-like GPCRs with RAMPs. The SBA strategy will be useful to search for additional GPCR-RAMP complexes and other interacting membrane protein pairs in cell lines and tissues.
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| 3. |
- Dahl, Leo, 1995-, et al.
(författare)
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Multiplexed selectivity screening of anti-GPCR antibodies
- 2023
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 9:18
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Tidskriftsartikel (refereegranskat)abstract
- G protein-coupled receptors (GPCRs) control critical cellular signaling pathways. Therapeutic agents including anti-GPCR antibodies (Abs) are being developed to modulate GPCR function. However, validating the selectivity of anti-GPCR Abs is challenging because of sequence similarities among individual receptors within GPCR sub-families. To address this challenge, we developed a multiplexed immunoassay to test >400 anti-GPCR Abs from the Human Protein Atlas targeting a customized library of 215 expressed and solubilized GPCRs representing all GPCR subfamilies. We found that-61% of Abs tested were selective for their intended target,-11% bound off -target, and-28% did not bind to any GPCR. Antigens of on-target Abs were, on average, significantly longer, more disordered, and less likely to be buried in the interior of the GPCR protein than the other Abs. These results provide important insights into the immunogenicity of GPCR epitopes and form a basis for designing therapeu-tic Abs and for detecting pathological auto-Abs against GPCRs.
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| 4. |
- Kotliar, Ilana B., et al.
(författare)
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Elucidating the Interactome of G Protein-Coupled Receptors and Receptor Activity-Modifying Proteins
- 2023
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Ingår i: Pharmacological Reviews. - : American Society for Pharmacology & Experimental Therapeutics (ASPET). - 0031-6997 .- 1521-0081. ; 75:1
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Forskningsöversikt (refereegranskat)abstract
- G protein-coupled receptors (GPCRs) are known to interact with several other classes of integral membrane proteins that modulate their biology and pharmacology. However, the extent of these interactions and the mechanisms of their effects are not well understood. For example, one class of GPCR-interacting proteins, receptor activity-modifying proteins (RAMPs), comprise three related and ubiquitously expressed single-transmembrane span proteins. The RAMP family was discovered more than two decades ago, and since then GPCR-RAMP interactions and their functional consequences on receptor trafficking and ligand selectivity have been documented for several secretin (class B) GPCRs, most notably the calcitonin receptor-like receptor. Recent bioinformatics and multiplexed experimental studies suggest that GPCR-RAMP interactions might bemuchmore widespread than previously anticipated. Recently, cryo-electron microscopy has provided high-resolution structures of GPCR-RAMP-ligand complexes, and drugs have been developed that target GPCR-RAMP complexes. In this review, we provide a summary of recent advances in techniques that allow the discovery of GPCR-RAMP interactions and their functional consequences and highlight prospects for future advances. We also provide an up-to-date list of reported GPCR-RAMP interactions based on a review of the current literature.
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