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Matúš D, Post WB, Groß VE, Knierim AB, Kuhn CK, Fiedler F, Tietgen DB, Schön JL, Schöneberg T, Prömel S. The N terminus-only (trans) function of the adhesion G protein-coupled receptor latrophilin-1 controls multiple processes in reproduction of Caenorhabditis elegans. G3 (BETHESDA, MD.) 2024; 14:jkae206. [PMID: 39243387 PMCID: PMC11540312 DOI: 10.1093/g3journal/jkae206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2024] [Accepted: 08/16/2024] [Indexed: 09/09/2024]
Abstract
Adhesion G protein-coupled receptors are unique molecules. They are able to transmit classical signals via G protein activation as well as mediate functions solely through their extracellular N termini, completely independently of the seven transmembrane helices domain and the C terminus. This dual mode of action is highly unusual for G protein-coupled receptors and allows for a plethora of possible cellular consequences. However, the physiological implications and molecular details of this N terminus-mediated signaling are poorly understood. Here, we show that several distinct seven transmembrane helices domain-independent/trans functions of the adhesion G protein-coupled receptor latrophilin homolog latrophilin-1 in the nematode Caenorhabditis elegans together regulate reproduction: sperm guidance, ovulation, and germ cell apoptosis. In these contexts, the receptor elicits its functions in a noncell autonomous manner. The functions might be realized through alternative splicing of the receptor specifically generating N terminus-only variants. Thus, our findings shed light on the versatility of seven transmembrane helices domain-independent/N terminus-only/trans functions of adhesion G protein-coupled receptor and discuss possible molecular details.
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Affiliation(s)
- Daniel Matúš
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA 94305, USA
| | - Willem Berend Post
- Department of Biology, Institute of Cell Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Victoria Elisabeth Groß
- Department of Biology, Institute of Cell Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Alexander Bernd Knierim
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
- IFB Adiposity Diseases, Leipzig University Medical Center, 04103 Leipzig, Germany
| | - Christina Katharina Kuhn
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
- Department of Diagnostics, Fraunhofer Institute for Cell Therapy and Immunology (IZI), 04103 Leipzig, Germany
| | - Franziska Fiedler
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
| | - Darian Benno Tietgen
- Department of Biology, Institute of Cell Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
| | - Johanna Lena Schön
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
- Department of Dermatology, Venereology and Allergology, Leipzig University Medical Center, Leipzig University, 04103 Leipzig, Germany
| | - Torsten Schöneberg
- Medical Faculty, Rudolf Schönheimer Institute of Biochemistry, Leipzig University, 04103 Leipzig, Germany
- School of Medicine, University of Global Health Equity, Kigali 6955, Rwanda
| | - Simone Prömel
- Department of Biology, Institute of Cell Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany
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Jakobs P, Rafflenbeul A, Post WB, Ale-Agha N, Groß VE, Pick S, Dolata S, Cox FF, von Ameln F, Eckermann O, Altschmied J, Prömel S, Haendeler J. The Adhesion GPCR ADGRL2/LPHN2 Can Protect Against Cellular and Organismal Dysfunction. Cells 2024; 13:1826. [PMID: 39594576 PMCID: PMC11592504 DOI: 10.3390/cells13221826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2024] [Revised: 10/30/2024] [Accepted: 10/31/2024] [Indexed: 11/28/2024] Open
Abstract
The most common trigger of sepsis and septic shock is bacterial lipopolysaccharide (LPS). Endothelial cells are among the first to encounter LPS directly. Generally, their function is closely linked to active endothelial NO Synthase (eNOS), which is significantly reduced under septic conditions. LPS treatment of endothelial cells leads to their activation and apoptosis, resulting in loss of integrity and vascular leakage, a hallmark of septic shock. Hence, therapies that prevent endothelial leakage or restore the endothelial barrier would be invaluable for patients. Adhesion GPCRs (aGPCRs) have been largely overlooked in this context, although particularly one of them, ADGRL2/LPHN2, has been implicated in endothelial barrier function. Our study shows that overexpression of ADGRL2 protects endothelial cells from LPS-induced activation, apoptosis, and impaired migration. Mechanistically, ADGRL2 preserves eNOS activity by shifting its binding from Caveolin-1 to Heat Shock Protein 90. Furthermore, ADGRL2 enhances antioxidative responses by increasing NRF2 activity. Notably, we found that this function may be evolutionarily conserved. In the absence of lat-2, a homolog of ADGRL2 in Caenorhabditis elegans, worms show higher ROS levels and altered stress response gene expression. Additionally, lat-2 mutants have a significantly reduced lifespan, altogether indicating a protective role of ADGRL2 against oxidative stress across species.
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Affiliation(s)
- Philipp Jakobs
- Cardiovascular Degeneration, Haendeler Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (N.A.-A.); (O.E.)
| | - Anne Rafflenbeul
- Cardiovascular Degeneration, Altschmied Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (A.R.); (F.F.C.); (F.v.A.); (J.A.)
| | - Willem Berend Post
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (W.B.P.); (V.E.G.); (S.P.); (S.D.)
| | - Niloofar Ale-Agha
- Cardiovascular Degeneration, Haendeler Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (N.A.-A.); (O.E.)
| | - Victoria Elisabeth Groß
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (W.B.P.); (V.E.G.); (S.P.); (S.D.)
| | - Stephanie Pick
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (W.B.P.); (V.E.G.); (S.P.); (S.D.)
| | - Sascha Dolata
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (W.B.P.); (V.E.G.); (S.P.); (S.D.)
| | - Fiona F. Cox
- Cardiovascular Degeneration, Altschmied Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (A.R.); (F.F.C.); (F.v.A.); (J.A.)
| | - Florian von Ameln
- Cardiovascular Degeneration, Altschmied Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (A.R.); (F.F.C.); (F.v.A.); (J.A.)
| | - Olaf Eckermann
- Cardiovascular Degeneration, Haendeler Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (N.A.-A.); (O.E.)
| | - Joachim Altschmied
- Cardiovascular Degeneration, Altschmied Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (A.R.); (F.F.C.); (F.v.A.); (J.A.)
| | - Simone Prömel
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (W.B.P.); (V.E.G.); (S.P.); (S.D.)
| | - Judith Haendeler
- Cardiovascular Degeneration, Haendeler Group, Clinical Chemistry and Laboratory Diagnostics, Medical Faculty, University Hospital and Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany; (P.J.); (N.A.-A.); (O.E.)
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Kuhn CK, Stenzel U, Berndt S, Liebscher I, Schöneberg T, Horn S. The repertoire and structure of adhesion GPCR transcript variants assembled from publicly available deep-sequenced human samples. Nucleic Acids Res 2024; 52:3823-3836. [PMID: 38421639 DOI: 10.1093/nar/gkae145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 01/24/2024] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
Alternative splicing and multiple transcription start and termination sites can produce a diverse repertoire of mRNA transcript variants from a given gene. While the full picture of the human transcriptome is still incomplete, publicly available RNA datasets have enabled the assembly of transcripts. Using publicly available deep sequencing data from 927 human samples across 48 tissues, we quantified known and new transcript variants, provide an interactive, browser-based application Splice-O-Mat and demonstrate its relevance using adhesion G protein-coupled receptors (aGPCRs) as an example. On average, 24 different transcript variants were detected for each of the 33 human aGPCR genes, and several dominant transcript variants were not yet annotated. Variable transcription starts and complex exon-intron structures encode a flexible protein domain architecture of the N- and C termini and the seven-transmembrane helix domain (7TMD). Notably, we discovered the first GPCR (ADGRG7/GPR128) with eight transmembrane helices. Both the N- and C terminus of this aGPCR were intracellularly oriented, anchoring the N terminus in the plasma membrane. Moreover, the assessment of tissue-specific transcript variants, also for other gene classes, in our application may change the evaluation of disease-causing mutations, as their position in different transcript variants may explain tissue-specific phenotypes.
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Affiliation(s)
- Christina Katharina Kuhn
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Udo Stenzel
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Sandra Berndt
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Ines Liebscher
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
- Department of Biochemistry, School of Medicine, University of Global Health Equity (UGHE), PO Box 6955 Kigali, Rwanda
| | - Susanne Horn
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, University of Leipzig, 04103 Leipzig, Germany
- Institute of Translational Genomics, Helmholtz Zentrum München - German Research Center for Environmental Health, 85764 Neuherberg, Germany
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Schön JL, Groß VE, Post WB, Daum A, Matúš D, Pilz J, Schnorr R, Horn S, Bäumers M, Weidtkamp-Peters S, Hughes S, Schöneberg T, Prömel S. The adhesion GPCR and PCP component flamingo (FMI-1) alters body size and regulates the composition of the extracellular matrix. Matrix Biol 2024; 128:1-10. [PMID: 38378098 DOI: 10.1016/j.matbio.2024.02.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Revised: 02/02/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
The extracellular matrix (ECM) is a network of macromolecules that presents a vital scaffold for cells and enables multiple ways of cellular communication. Thus, it is essential for many physiological processes such as development, tissue morphogenesis, homeostasis, the shape and partially the size of the body and its organs. To ensure these, the composition of the ECM is tissue-specific and highly dynamic. ECM homeostasis is therefore tightly controlled by several mechanisms. Here, we show that FMI-1, the homolog of the Adhesion GPCR Flamingo/CELSR/ADGRC in the nematode Caenorhabditis elegans, modulates the composition of the ECM by controlling the production both of ECM molecules such as collagens and also of ECM modifying enzymes. Thereby, FMI-1 affects the morphology and functionality of the nematode´s cuticle, which is mainly composed of ECM, and also modulates the body size. Mechanistic analyses highlight the fact that FMI-1 exerts its function from neurons non-cell autonomously (trans) solely via its extracellular N terminus. Our data support a model, by which the activity of the receptor, which has a well-described role in the planar cell polarity (PCP) pathway, involves the PCP molecule VANG-1, but seems to be independent of the DBL-1/BMP pathway.
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Affiliation(s)
- Johanna Lena Schön
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany; Department of Dermatology, Venereology and Allergology, Leipzig University Medical Center, Leipzig University, Leipzig, Germany
| | - Victoria Elisabeth Groß
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Willem Berend Post
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Alexandra Daum
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Daniel Matúš
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany; Department of Molecular and Cellular Physiology, Stanford University, Stanford, USA
| | - Johanna Pilz
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Rene Schnorr
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Susanne Horn
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany
| | - Miriam Bäumers
- Center for Advanced Imaging, Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | | | - Samantha Hughes
- A-LIFE, Section Environmental Health and Toxicology, Free University Amsterdam, Amsterdam, the Netherlands
| | - Torsten Schöneberg
- Rudolf Schönheimer Institute of Biochemistry, Medical Faculty, Leipzig University, Leipzig, Germany; School of Medicine, University of Global Health Equity, Kigali, Rwanda
| | - Simone Prömel
- Institute of Cell Biology, Department of Biology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
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Medrano E, Collins KM. Muscle-directed mechanosensory feedback activates egg-laying circuit activity and behavior in Caenorhabditis elegans. Curr Biol 2023; 33:2330-2339.e8. [PMID: 37236183 PMCID: PMC10280788 DOI: 10.1016/j.cub.2023.05.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 03/29/2023] [Accepted: 05/03/2023] [Indexed: 05/28/2023]
Abstract
Mechanosensory feedback of the internal reproductive state drives decisions about when and where to reproduce.1 For instance, stretch in the Drosophila reproductive tract produced by artificial distention or from accumulated eggs regulates the attraction to acetic acid to ensure optimal oviposition.2 How such mechanosensory feedback modulates neural circuits to coordinate reproductive behaviors is incompletely understood. We previously identified a stretch-dependent homeostat that regulates egg laying in Caenorhabditis elegans. Sterilized animals lacking eggs show reduced Ca2+ transient activity in the presynaptic HSN command motoneurons that drive egg-laying behavior, while animals forced to accumulate extra eggs show dramatically increased circuit activity that restores egg laying.3 Interestingly, genetic ablation or electrical silencing of the HSNs delays, but does not abolish, the onset of egg laying,3,4,5 with animals recovering vulval muscle Ca2+ transient activity upon egg accumulation.6 Using an acute gonad microinjection technique to mimic changes in pressure and stretch resulting from germline activity and egg accumulation, we find that injection rapidly stimulates Ca2+ activity in both neurons and muscles of the egg-laying circuit. Injection-induced vulval muscle Ca2+ activity requires L-type Ca2+ channels but is independent of presynaptic input. Conversely, injection-induced neural activity is disrupted in mutants lacking the vulval muscles, suggesting "bottom-up" feedback from muscles to neurons. Direct mechanical prodding activates the vulval muscles, suggesting that they are the proximal targets of the stretch-dependent stimulus. Our results show that egg-laying behavior in C. elegans is regulated by a stretch-dependent homeostat that scales postsynaptic muscle responses with egg accumulation in the uterus.
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Affiliation(s)
- Emmanuel Medrano
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA
| | - Kevin M Collins
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL 33146, USA.
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Goodman MB, Haswell ES, Vásquez V. Mechanosensitive membrane proteins: Usual and unusual suspects in mediating mechanotransduction. J Gen Physiol 2023; 155:e202213248. [PMID: 36696153 PMCID: PMC9930137 DOI: 10.1085/jgp.202213248] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
This Viewpoint, which accompanies a Special Issue focusing on membrane mechanosensors, discusses unifying and unique features of both established and emerging mechanosensitive (MS) membrane proteins, their distribution across protein families and phyla, and current and future challenges in the study of these important proteins and their partners. MS membrane proteins are essential for tissue development, cellular motion, osmotic homeostasis, and sensing external and self-generated mechanical cues like those responsible for touch and proprioception. Though researchers' attention and this Viewpoint focus on a few famous ion channels that are considered the usual suspects as MS mechanosensors, we also discuss some of the more unusual suspects, such as G-protein coupled receptors. As the field continues to grow, so too will the list of proteins suspected to function as mechanosensors and the diversity of known MS membrane proteins.
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Affiliation(s)
- Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, USA
| | - Elizabeth S. Haswell
- Department of Biology, Center for Engineering Mechanobiology, Washington University in St. Louis, St. Louis, MO, USA
| | - Valeria Vásquez
- Department of Physiology, College of Medicine, University of Tennessee Health Science Center, Memphis, TN, USA
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Nojima Y, Toriyama M, Tago K, Mizuno N, Morishita K, Itoh H. GPR56 C-terminal fragment mediates signal received by N-terminal fragment of another adhesion GPCR Latrophilin1 in neurons. Genes Cells 2023; 28:83-96. [PMID: 36453010 DOI: 10.1111/gtc.12994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022]
Abstract
Adhesion GPCRs (aGPCRs) are a subfamily of GPCRs that are involved in cell adhesion, cell proliferation, and cell migration in various tissues. G protein-coupled receptor proteolytic site (GPS) of aGPCR is required to cleave the extracellular domain autocatalytically, generating two fragments; a N-terminal fragment (NTF) and a C-terminal fragment (CTF) containing seven transmembrane structure. NTF can interact with CTF non-covalently after cleavage, however the physiological significance of the cleavage of aGPCR at GPS, and also the interaction between NTF and CTF have not been fully clarified yet. In this study, we first investigated the expression profiles of two aGPCRs, GPR56/ADGRG1, and LPHN1/ADGRL1 in mouse brain, and found that the NTF and CTF of GPR56 independently expressed in different brain region at different developmental stages. Immunoprecipitation of GPR56CTF co-immunoprecipitated LPHN1NTF from mouse brain and HEK293T cells expressing both fragments. Stimulation with LPHN1 ligand, α-Latrotoxin N4C (αLTXN4C), to cells expressing LPHN1NTF and GPR56CTF increased intracellular Ca2+ concentration ([Ca2+ ]i). We also demonstrated that GPR56KO mouse neurons attenuated their Ca2+ response to αLTXN4C. These results suggest the possibility of functional and chimeric complex containing LPHN1NTF and GPR56CTF in neuronal signal transduction.
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Affiliation(s)
- Yusuke Nojima
- Laboratory of Molecular Signal Transduction, Division of Biological Science, Nara Institute of Science and Technology, Nara, Japan
| | - Manami Toriyama
- Laboratory of Molecular Signal Transduction, Division of Biological Science, Nara Institute of Science and Technology, Nara, Japan
| | - Kenji Tago
- Division of Structural Biochemistry, Department of Biochemistry, Jichi Medical University, Tochigi, Japan
| | - Norikazu Mizuno
- Faculty of Pharmaceutical Sciences, Aomori University, Aomori, Japan
| | - Kazuhiro Morishita
- Project for Advanced Medical Research and Development, Project Research Division, Frontier Science Research Center, University of Miyazaki, Miyazaki, Japan
| | - Hiroshi Itoh
- Laboratory of Molecular Signal Transduction, Division of Biological Science, Nara Institute of Science and Technology, Nara, Japan
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Adhesion G protein-coupled receptors-Structure and functions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 195:1-25. [PMID: 36707149 DOI: 10.1016/bs.pmbts.2022.06.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Adhesion G protein-coupled receptors (aGPCRs) are an ancient class of receptors that represent some of the largest transmembrane-integrated proteins in humans. First recognized as surface markers on immune cells, it took more than a decade to appreciate their 7-transmembrane structure, which is reminiscent of GPCRs. Roughly 30 years went by before the first functional proof of an interaction with a G protein was published. Besides classic features of GPCRs (extracellular N terminus, 7-transmembrane region, intracellular C terminus), aGPCRs display a distinct N-terminal structure, which harbors the highly conserved GPCR autoproteolysis-inducing (GAIN) domain with the GPCR proteolysis site (GPS) in addition to several functional domains. Several human diseases have been associated with variants of aGPCRs and subsequent animal models have been established to investigate these phenotypes. Much progress has been made in recent years to decipher the structure and functions of these receptors. This chapter gives an overview of our current understanding with respect to the molecular structural patterns governing aGPCR activation and the contribution of these giant molecules to the development of pathologies.
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