1
|
Bower JB, Robson SA, Ziarek JJ. Insights on the G protein-coupled receptor helix 8 solution structure and orientation using a neurotensin receptor 1 peptide. Protein Sci 2024; 33:e4976. [PMID: 38757374 PMCID: PMC11099793 DOI: 10.1002/pro.4976] [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: 02/02/2024] [Revised: 03/12/2024] [Accepted: 03/14/2024] [Indexed: 05/18/2024]
Abstract
G-protein coupled receptors (GPCRs) are the largest class of membrane proteins encoded in the human genome with high pharmaceutical relevance and implications to human health. These receptors share a prevalent architecture of seven transmembrane helices followed by an intracellular, amphipathic helix 8 (H8) and a disordered C-terminal tail (Ctail). Technological advancements have led to over 1000 receptor structures in the last two decades, yet frequently H8 and the Ctail are conformationally heterogeneous or altogether absent. Here we synthesize a peptide comprising the neurotensin receptor 1 (NTS1) H8 and Ctail (H8-Ctail) to investigate its structural stability, conformational dynamics, and orientation in the presence of detergent and phospholipid micelles, which mimic the membrane. Circular dichroism (CD) and nuclear magnetic resonance (NMR) measurements confirm that zwitterionic 1,2-diheptanoyl-sn-glycero-3-phosphocholine is a potent stabilizer of H8 structure, whereas the commonly-used branched detergent lauryl maltose neopentyl glycol (LMNG) is unable to completely stabilize the helix - even at amounts four orders of magnitude greater than its critical micellar concentration. We then used NMR spectroscopy to assign the backbone chemical shifts. A series of temperature and lipid titrations were used to define the H8 boundaries as F376-R392 from chemical shift perturbations, changes in resonance intensity, and chemical-shift-derived phi/psi angles. Finally, the H8 azimuthal and tilt angles, defining the helix orientation relative of the membrane normal were measured using paramagnetic relaxation enhancement NMR. Taken together, our studies reveal the H8-Ctail region is sensitive to membrane physicochemical properties and is capable of more adaptive behavior than previously suggested by static structural techniques.
Collapse
Affiliation(s)
- James B. Bower
- Molecular and Cellular Biochemistry DepartmentIndiana UniversityBloomingtonIndianaUSA
| | - Scott A. Robson
- Department of PharmacologyNorthwestern University Feinberg School of MedicineChicagoIllinoisUSA
| | - Joshua J. Ziarek
- Molecular and Cellular Biochemistry DepartmentIndiana UniversityBloomingtonIndianaUSA
- Department of PharmacologyNorthwestern University Feinberg School of MedicineChicagoIllinoisUSA
| |
Collapse
|
2
|
Verma DK, Malhotra H, Woellert T, Calvert PD. Hydrophobic interaction between the TM1 and H8 is essential for rhodopsin trafficking to vertebrate photoreceptor outer segments. J Biol Chem 2023; 299:105412. [PMID: 37918805 PMCID: PMC10687059 DOI: 10.1016/j.jbc.2023.105412] [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: 05/16/2023] [Revised: 10/15/2023] [Accepted: 10/25/2023] [Indexed: 11/04/2023] Open
Abstract
A major unsolved question in vertebrate photoreceptor biology is the mechanism of rhodopsin transport to the outer segment. In rhodopsin-like class A G protein-coupled receptors, hydrophobic interactions between C-terminal α-helix 8 (H8), and transmembrane α-helix-1 (TM1) have been shown to be important for transport to the plasma membrane, however whether this interaction is important for rhodopsin transport to ciliary rod outer segments is not known. We examined the crystal structures of vertebrate rhodopsins and class A G protein-coupled receptors and found a conserved network of predicted hydrophobic interactions. In Xenopus rhodopsin (xRho), this interaction corresponds to F313, L317, and L321 in H8 and M57, V61, and L68 in TM1. To evaluate the role of H8-TM1 hydrophobic interactions in rhodopsin transport, we expressed xRho-EGFP where hydrophobic residues were mutated in Xenopus rods and evaluated the efficiency of outer segment enrichment. We found that substituting L317 and M57 with hydrophilic residues had the strongest impact on xRho mislocalization. Substituting hydrophilic amino acids at positions L68, F313, and L321 also had a significant impact. Replacing L317 with M resulted in significant mislocalization, indicating that the hydrophobic interaction between residues 317 and 57 is exquisitely sensitive. The corresponding experiment in bovine rhodopsin expressed in HEK293 cells had a similar effect, showing that the H8-TM1 hydrophobic network is essential for rhodopsin transport in mammalian species. Thus, for the first time, we show that a hydrophobic interaction between H8 and TM1 is critical for efficient rhodopsin transport to the vertebrate photoreceptor ciliary outer segment.
Collapse
Affiliation(s)
- Dipesh Kumar Verma
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Himanshu Malhotra
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Torsten Woellert
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, USA
| | - Peter D Calvert
- Department of Ophthalmology and Visual Sciences, SUNY Upstate Medical University, Syracuse, New York, USA.
| |
Collapse
|
3
|
Thomas P, Pang Y, Kelder J. Membrane progesterone receptors on the cell membrane: A review highlighting potential export motifs in mPRα regulating its trafficking to the cell surface. Steroids 2023; 199:109295. [PMID: 37558174 DOI: 10.1016/j.steroids.2023.109295] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 08/03/2023] [Accepted: 08/05/2023] [Indexed: 08/11/2023]
Abstract
Substantial progress has been made in our understanding of the nongenomic actions, ligand binding, intracellular signaling pathways, and functions of membrane progesterone receptors (mPRs) in reproductive and nonreproductive tissues since their discovery 20 years ago. The five mPRs are members of the progestin adipoQ receptor (PAQR) family which also includes adiponectin receptors (AdipoRs). However, unlike AdipoRs, the 3-D structures of mPRs are unknown, and their structural characteristics remain poorly understood. The mechanisms regulating mPR functions and their trafficking to the cell surface have received little attention and have not been systematically reviewed. This paper summarizes some structural aspects of mPRs, including the ligand binding pocket of mPRα recently derived from homology modeling with AdipoRs, and the proposed topology of mPRs from the preponderance of positively charged amino acid residues in their intracellular domains. The mechanisms of trafficking membrane receptors to the cell surface are discussed, including the amino acid motifs involved with their export to the cell surface, the roles of adaptor proteins, and post-translational glycosylation and palmitoylation modifications that promote cell surface expression and retention. Evidence for similar mechanisms regulating the expression and functions of mPRs on the cell surface is discussed, including the identification of potential export motifs on mPRα required for its trafficking to the cell membrane. Collectively, these results have identified several potential mechanisms regulating the expression and functions of mPRs on the cell membrane for further investigation.
Collapse
Affiliation(s)
- Peter Thomas
- University of Texas at Austin Marine Science Institute, 750 Channel View Drive, Port Aransas, TX 78373, USA.
| | - Yefei Pang
- University of Texas at Austin Marine Science Institute, 750 Channel View Drive, Port Aransas, TX 78373, USA
| | - Jan Kelder
- Theoretical & Computational Chemistry, Radboud University Nijmegen, Heyendaalseweg 135, 6525 AJ Nijmegen, The Netherlands
| |
Collapse
|
4
|
Renna SA, McKenzie SE, Michael JV. Species Differences in Platelet Protease-Activated Receptors. Int J Mol Sci 2023; 24:ijms24098298. [PMID: 37176005 PMCID: PMC10179473 DOI: 10.3390/ijms24098298] [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: 03/28/2023] [Revised: 04/21/2023] [Accepted: 05/02/2023] [Indexed: 05/15/2023] Open
Abstract
Protease-activated receptors (PARs) are a class of integral membrane proteins that are cleaved by a variety of proteases, most notably thrombin, to reveal a tethered ligand and promote activation. PARs are critical mediators of platelet function in hemostasis and thrombosis, and therefore are attractive targets for anti-platelet therapies. Animal models studying platelet PAR physiology have relied heavily on genetically modified mouse strains, which have provided ample insight but have some inherent limitations. The current review aims to summarize the notable PAR expression and functional differences between the mouse and human, in addition to highlighting some recently developed tools to further study human physiology in mouse models.
Collapse
Affiliation(s)
- Stephanie A Renna
- Department of Medicine, The Cardeza Foundation for Hematologic Research, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Steven E McKenzie
- Department of Medicine, The Cardeza Foundation for Hematologic Research, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - James V Michael
- Department of Medicine, The Cardeza Foundation for Hematologic Research, Thomas Jefferson University, Philadelphia, PA 19107, USA
| |
Collapse
|
5
|
Respekta N, Pich K, Dawid M, Mlyczyńska E, Kurowska P, Rak A. The Apelinergic System: Apelin, ELABELA, and APJ Action on Cell Apoptosis: Anti-Apoptotic or Pro-Apoptotic Effect? Cells 2022; 12:cells12010150. [PMID: 36611944 PMCID: PMC9818302 DOI: 10.3390/cells12010150] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 12/23/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
The apelinergic system comprises two peptide ligands, apelin and ELABELA, and their cognate G-protein-coupled receptor, the apelin receptor APJ. Apelin is a peptide that was isolated from bovine stomach extracts; the distribution of the four main active forms, apelin-36, -17, -13, and pyr-apelin-13 differs between tissues. The mature form of ELABELA-32 can be transformed into forms called ELABELA-11 or -21. The biological function of the apelinergic system is multifaceted, and includes the regulation of angiogenesis, body fluid homeostasis, energy metabolism, and functioning of the cardiovascular, nervous, respiratory, digestive, and reproductive systems. This review summarises the mechanism of the apelinergic system in cell apoptosis. Depending on the cell/tissue, the apelinergic system modulates cell apoptosis by activating various signalling pathways, including phosphoinositide 3-kinase (PI3K), extracellular signal-regulated protein kinase (ERK1/2), protein kinase B (AKT), 5'AMP-activated protein kinase(AMPK), and protein kinase A (PKA). Apoptosis is critically important during various developmental processes, and any dysfunction leads to pathological conditions such as cancer, autoimmune diseases, and developmental defects. The purpose of this review is to present data that suggest a significant role of the apelinergic system as a potential agent in various therapies.
Collapse
|
6
|
Helix 8 in chemotactic receptors of the complement system. PLoS Comput Biol 2022; 18:e1009994. [PMID: 35862436 PMCID: PMC9359563 DOI: 10.1371/journal.pcbi.1009994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 08/08/2022] [Accepted: 06/09/2022] [Indexed: 11/19/2022] Open
Abstract
Host response to infection involves the activation of the complement system leading to the production of anaphylatoxins C3a and C5a. Complement factor C5a exerts its effect through the activation of C5aR1, chemotactic receptor 1, and triggers the G protein-coupled signaling cascade. Orthosteric and allosteric antagonists of C5aR1 are a novel strategy for anti-inflammatory therapies. Here, we discuss recent crystal structures of inactive C5aR1 in terms of an inverted orientation of helix H8, unobserved in other GPCR structures. An analysis of mutual interactions of subunits in the C5aR1—G protein complex has provided new insights into the activation mechanism of this distinct receptor. By comparing two C5aR receptors C5aR1 and C5aR2 we explained differences between their signaling pathways on the molecular level. By means of molecular dynamics we explained why C5aR2 cannot transduce signal through the G protein pathway but instead recruits beta-arrestin. A comparison of microsecond MD trajectories started from active and inactive C5aR1 receptor conformations has provided insights into details of local and global changes in the transmembrane domain induced by interactions with the Gα subunit and explained the impact of inverted H8 on the C5aR1 activation. Anaphylatoxin C5a produced as a host response to bacterial infections triggers the complement cascade through two chemotactic receptors: C5aR1 and C5aR2. Despite being classified as G protein-coupled receptors, these two receptors transduce the signal in two different ways—one with G protein and the other one with beta-arrestin only. Here, we demonstrated that microsecond molecular dynamics simulations can be used to discriminate one of these signaling pathways for a certain C5aR receptor subtype as indeed nonexistent. This functional selectivity of C5aR receptors results from their structural differences involving not only the receptor core, but also an inverted helix H8 of a much less amphipathic character in the case of C5aR2 than in C5aR1. In addition, transmembrane helix TM6 is shorter in C5aR2 compared to C5aR1, and thus the intracellular region consisting of TM5, ICL3 and TM6 is not stable enough to form any interactions with the G-alpha subunit. Conformational changes in C5aR1 contributing to the beginning of its activation were observed in changing over simulation time contact maps that were generated for interresidual distances and changed over the course of the simulation.
Collapse
|
7
|
Martínez-Morales JC, Romero-Ávila MT, Reyes-Cruz G, García-Sáinz JA. Roles of receptor phosphorylation and Rab proteins in G protein-coupled receptor function and trafficking. Mol Pharmacol 2021; 101:144-153. [PMID: 34969830 DOI: 10.1124/molpharm.121.000429] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Accepted: 12/22/2021] [Indexed: 11/22/2022] Open
Abstract
The G Protein-Coupled Receptors form the most abundant family of membrane proteins and are crucial physiological players in the homeostatic equilibrium, which we define as health. They also participate in the pathogenesis of many diseases and are frequent targets of therapeutic intervention. Considering their importance, it is not surprising that different mechanisms regulate their function, including desensitization, resensitization, internalization, recycling to the plasma membrane, and degradation. These processes are modulated in a highly coordinated and specific way by protein kinases and phosphatases, ubiquitin ligases, protein adaptors, interaction with multifunctional complexes, molecular motors, phospholipid metabolism, and membrane distribution. This review describes significant advances in the study of the regulation of these receptors by phosphorylation and endosomal traffic (where signaling can take place); we revisited the bar code hypothesis and include two additional observations: a) that different phosphorylation patterns seem to be associated with internalization and endosome sorting for recycling or degradation, and b) that, surprisingly, phosphorylation of some G protein-coupled receptors appears to be required for proper receptor insertion into the plasma membrane. Significance Statement G protein-coupled receptor phosphorylation is an early event in desensitization/ signaling switching, endosomal traffic, and internalization. These events seem crucial for receptor responsiveness, cellular localization, and fate (recycling/ degradation) with important pharmacological/ therapeutic implications. Phosphorylation sites vary depending on the cells in which they are expressed and on the stimulus that leads to such covalent modification. Surprisingly, evidence suggests that phosphorylation also seems to be required for proper insertion into the plasma membrane for some receptors.
Collapse
|
8
|
Dawid M, Mlyczyńska E, Jurek M, Respekta N, Pich K, Kurowska P, Gieras W, Milewicz T, Kotula-Balak M, Rak A. Apelin, APJ, and ELABELA: Role in Placental Function, Pregnancy, and Foetal Development-An Overview. Cells 2021; 11:cells11010099. [PMID: 35011661 PMCID: PMC8750556 DOI: 10.3390/cells11010099] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 12/21/2021] [Accepted: 12/24/2021] [Indexed: 11/17/2022] Open
Abstract
The apelinergic system, which includes the apelin receptor (APJ) as well as its two specific ligands, namely apelin and ELABELA (ELA/APELA/Toddler), have been the subject of many recent studies due to their pleiotropic effects in humans and other animals. Expression of these factors has been investigated in numerous tissues and organs—for example, the lungs, heart, uterus, and ovary. Moreover, a number of studies have been devoted to understanding the role of apelin and the entire apelinergic system in the most important processes in the body, starting from early stages of human life with regulation of placental function and the proper course of pregnancy. Disturbances in the balance of placental processes such as proliferation, apoptosis, angiogenesis, or hormone secretion may lead to specific pregnancy pathologies; therefore, there is a great need to search for substances that would help in their early diagnosis or treatment. A number of studies have indicated that compounds of the apelinergic system could serve this purpose. Hence, in this review, we summarized the most important reports about the role of apelin and the entire apelinergic system in the regulation of placental physiology and pregnancy.
Collapse
Affiliation(s)
- Monika Dawid
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Ewa Mlyczyńska
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Małgorzata Jurek
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Natalia Respekta
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Karolina Pich
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Patrycja Kurowska
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Wiktoria Gieras
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
| | - Tomasz Milewicz
- Department of Gynecological Endocrinology, Jagiellonian University Medical College, 31-501 Krakow, Poland;
| | - Małgorzata Kotula-Balak
- University Centre of Veterinary Medicine JU-UA, University of Agriculture in Krakow, 30-059 Krakow, Poland;
| | - Agnieszka Rak
- Laboratory of Physiology and Toxicology of Reproduction, Institute of Zoology and Biomedical Research, Jagiellonian University in Krakow, 30-387 Krakow, Poland; (M.D.); (E.M.); (M.J.); (N.R.); (K.P.); (P.K.); (W.G.)
- Correspondence: ; Tel.: +48-1-2664-5003
| |
Collapse
|
9
|
Geng S, Xu T, Sun Y. Genome-wide identification and analysis of chemokine receptor superfamily in miiuy croaker, Miichthys miiuy. FISH & SHELLFISH IMMUNOLOGY 2021; 118:343-353. [PMID: 34555531 DOI: 10.1016/j.fsi.2021.09.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Revised: 09/16/2021] [Accepted: 09/16/2021] [Indexed: 06/13/2023]
Abstract
The chemokine receptor (ChemR) superfamily, which is divided into 4 subfamilies (CXCR, CCR, XCR, and CX3CR), is the main receptors of chemokines in innate immune responses. In the current study, we have identified 27 ChemRs in miiuy croaker: 13 CCR genes, 11 CXCR genes, and 3 XCR genes. Multiple characteristics of these genes, including phylogeny, gene structures, conserved motifs, chromosome locations, evolutionary mechanism, and expression levels upon the bacterial challenge were analyzed. Gene structure and location analysis showed that all ChemR genes contain fewer introns (≤4) and they are unevenly distributed on the 12 chromosomes. And the XCR subfamily of miiuy croaker don't have the DRY motif of ChemR. Phylogenetic and synteny analysis showed that these genes experienced tandem and segmental duplication event in several species, and tandem duplication might be the main expansion way in miiuy croaker. The major ChemRs of each orthologous group in vertebrates were selected for molecular evolution analysis, the results of which indicated that compared with vertebrates, ChemRs of teleost fishes may have a relatively high evolutionary dynamic. In addition, a total of 21 positively selected codons were detected in vertebrate ChemRs under Model 8. RNA-Seq analysis and qRT-PCR verification demonstrated that CXCR3.2, CXCR5, and XCR1 genes were up-regulated significantly upon the Vibrio harveyi infection. These results provide valuable information for investigating the evolutionary relationships of chemokine receptor superfamily in miiuy croaker and laid the basis for further functional analysis.
Collapse
Affiliation(s)
- Shang Geng
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China
| | - Tianjun Xu
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Laboratory of Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; National Pathogen Collection Center for Aquatic Animals, Shanghai Ocean University, China
| | - Yuena Sun
- Laboratory of Fish Molecular Immunology, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai, China; Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources (Shanghai Ocean University), Ministry of Education, China.
| |
Collapse
|
10
|
Solís KH, Romero-Ávila MT, Guzmán-Silva A, García-Sáinz JA. The LPA 3 Receptor: Regulation and Activation of Signaling Pathways. Int J Mol Sci 2021; 22:ijms22136704. [PMID: 34201414 PMCID: PMC8269014 DOI: 10.3390/ijms22136704] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 06/08/2021] [Accepted: 06/12/2021] [Indexed: 12/17/2022] Open
Abstract
The lysophosphatidic acid 3 receptor (LPA3) participates in different physiological actions and in the pathogenesis of many diseases through the activation of different signal pathways. Knowledge of the regulation of the function of the LPA3 receptor is a crucial element for defining its roles in health and disease. This review describes what is known about the signaling pathways activated in terms of its various actions. Next, we review knowledge on the structure of the LPA3 receptor, the domains found, and the roles that the latter might play in ligand recognition, signaling, and cellular localization. Currently, there is some information on the action of LPA3 in different cells and whole organisms, but very little is known about the regulation of its function. Areas in which there is a gap in our knowledge are indicated in order to further stimulate experimental work on this receptor and on other members of the LPA receptor family. We are convinced that knowledge on how this receptor is activated, the signaling pathways employed and how the receptor internalization and desensitization are controlled will help design new therapeutic interventions for treating diseases in which the LPA3 receptor is implicated.
Collapse
|
11
|
Chandrabalan A, Ramachandran R. Molecular mechanisms regulating Proteinase‐Activated Receptors (PARs). FEBS J 2021; 288:2697-2726. [DOI: 10.1111/febs.15829] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/10/2021] [Accepted: 03/18/2021] [Indexed: 12/13/2022]
Affiliation(s)
- Arundhasa Chandrabalan
- Department of Physiology and Pharmacology Schulich School of Medicine and Dentistry University of Western Ontario London Canada
| | - Rithwik Ramachandran
- Department of Physiology and Pharmacology Schulich School of Medicine and Dentistry University of Western Ontario London Canada
| |
Collapse
|
12
|
Liu R, Du K, Ormanns J, Adolfi MC, Schartl M. Melanocortin 4 receptor signaling and puberty onset regulation in Xiphophorus swordtails. Gen Comp Endocrinol 2020; 295:113521. [PMID: 32470471 DOI: 10.1016/j.ygcen.2020.113521] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 04/15/2020] [Accepted: 05/22/2020] [Indexed: 01/01/2023]
Abstract
Fish of the genus Xiphophorus provide a prominent example of genetic control of male body size and reproductive tactics. In X.nigrensis and X.multilineatus, puberty onset and body length are determined by melanocortin 4 receptor (Mc4r) allelic and copy number variations which were proposed to fine-tune the signaling output of the system. Accessory protein Mrap2 is required for growth across species by affecting Mc4r signaling. The molecular mechanism how Mc4r signaling controls puberty regulation in Xiphophorus and whether the interaction with Mrap2 is also involved was so far unclear. Hence, we examined Mc4r and Mrap2 in X.nigrensis and X.multilineatus, in comparison to a more distantly related species, X.hellerii. mc4r and mrap2 transcripts co-localized in the hypothalamus and preoptic regions in large males, small males and females of X.nigrensis, with similar signal strength for mrap2 but higher expression of mc4r in large males. This overexpression is constituted by wild-type and one subtype of mutant alleles. In vitro studies revealed that Mrap2 co-expressed with Mc4r increased cAMP production but did not change EC50. Cells co-expressing the wild-type and one mutant allele showed lower cAMP signaling than Mc4r wild-type cells. This indicates a role of Mc4r alleles, but not Mrap2, in puberty signaling. Different from X.nigrensis and X.multilineatus, X.hellerii has only wild-type alleles, but also shows a puberty onset and body length polymorphism, despite the absence of mutant alleles. Like in the two other species, mc4r and mrap2 transcripts colocalized and mc4r is expressed at substantially higher levels in large males. This demonstrates that puberty and growth regulation mechanism may not be identical even within same genus.
Collapse
MESH Headings
- Adaptor Proteins, Signal Transducing/metabolism
- Alleles
- Amino Acid Sequence
- Animals
- Cyprinodontiformes/genetics
- Cyprinodontiformes/metabolism
- DNA Copy Number Variations/genetics
- Female
- Gene Expression Regulation, Developmental
- Male
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptor, Melanocortin, Type 4/chemistry
- Receptor, Melanocortin, Type 4/genetics
- Receptor, Melanocortin, Type 4/metabolism
- Sexual Maturation/physiology
- Signal Transduction
Collapse
Affiliation(s)
- Ruiqi Liu
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Kang Du
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Jenny Ormanns
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Mateus C Adolfi
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany
| | - Manfred Schartl
- Physiological Chemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; Developmental Biochemistry, Biocenter, University of Wuerzburg, Wuerzburg, Germany; The Xiphophorus Genetic Stock Center, Department of Chemistry and Biochemistry, Texas State University, San Marcos, TX, USA.
| |
Collapse
|
13
|
Dijkman PM, Muñoz-García JC, Lavington SR, Kumagai PS, dos Reis RI, Yin D, Stansfeld PJ, Costa-Filho AJ, Watts A. Conformational dynamics of a G protein-coupled receptor helix 8 in lipid membranes. SCIENCE ADVANCES 2020; 6:eaav8207. [PMID: 32851152 PMCID: PMC7428336 DOI: 10.1126/sciadv.aav8207] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 07/02/2020] [Indexed: 05/21/2023]
Abstract
G protein-coupled receptors (GPCRs) are the largest and pharmaceutically most important class of membrane proteins encoded in the human genome, characterized by a seven-transmembrane helix architecture and a C-terminal amphipathic helix 8 (H8). In a minority of GPCR structures solved to date, H8 either is absent or adopts an unusual conformation. The controversial existence of H8 of the class A GPCR neurotensin receptor 1 (NTS1) has been examined here for the nonthermostabilized receptor in a functionally supporting membrane environment using electron paramagnetic resonance, molecular dynamics simulations, and circular dichroism. Lipid-protein interactions with phosphatidylserine and phosphatidylethanolamine lipids, in particular, stabilize the residues 374 to 390 of NTS1 into forming a helix. Furthermore, introduction of a helix-breaking proline residue in H8 elicited an increase in ß-arrestin-NTS1 interactions observed in pull-down assays, suggesting that the structure and/or dynamics of H8 might play an important role in GPCR signaling.
Collapse
Affiliation(s)
- Patricia M. Dijkman
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Juan C. Muñoz-García
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Steven R. Lavington
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Patricia Suemy Kumagai
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense 400, C.P. 369, São Carlos SP 13560-970, Brazil
| | - Rosana I. dos Reis
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Daniel Yin
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Phillip J. Stansfeld
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- School of Life Sciences & Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - Antonio José Costa-Filho
- Departamento de Física, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes 3900, Ribeirão Preto SP 14040-901, Brazil
| | - Anthony Watts
- Biomembrane Structure Unit, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
- Corresponding author.
| |
Collapse
|
14
|
Issahaku AR, Agoni C, Kumi RO, Olotu FA, Soliman MES. Lipid-Embedded Molecular Dynamics Simulation Model for Exploring the Reverse Prostaglandin D2 Agonism of CT-133 towards CRTH2 in the Treatment of Type-2 Inflammation Dependent Diseases. Chem Biodivers 2020; 17:e1900548. [PMID: 32034875 DOI: 10.1002/cbdv.201900548] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 02/07/2020] [Indexed: 12/17/2022]
Abstract
Chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2) has been involved in several inflammation dependent diseases by mediating the chemotaxis of pro-inflammatory cells in response to allergy and other responses through PGD2 ligation. This CRTH2-PGD2 signaling pathway has become a target for treating allergic and type 2 inflammation dependent diseases, with many inhibitors developed to target the PGD2 binding pocket. One of such inhibitors is the ramatroban analog, CT-133, which exhibited therapeutic potency cigarette smoke-induced acute lung injury in patients. Nonetheless, the molecular mechanism and structural dynamics that accounts for its therapeutic prowess remain unclear. Employing computational tools, this study revealed that although the carboxylate moiety in CT-133 and the native agonist PGD2 aided in their stability within the CRTH2 binding pocket, the tetrahydrocarbazole group of CT-133 engaged in strong interactions with binding pocket residues which could have formed as the basis of the antagonistic advantage of CT-133. Tetrahydrocarbazole group interactions also enhanced the relative stability CT-133 within the binding pocket which consequently favored CT-133 binding affinity. CT-133 binding also induced an inactive or 'desensitized' state in the helix 8 of CRTH2 which could conversely favor the recruitment of arrestin. These revelations would aid in the speedy development of small molecule inhibitors of CRTH2 in the treatment of type 2 inflammation dependent diseases.
Collapse
Affiliation(s)
- Abdul Rashid Issahaku
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4001, South Africa
| | - Clement Agoni
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4001, South Africa
| | - Ransford O Kumi
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4001, South Africa
| | - Fisayo A Olotu
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4001, South Africa
| | - Mahmoud E S Soliman
- Molecular Bio-computation and Drug Design Laboratory, School of Health Sciences, University of KwaZulu-Natal, Westville Campus, Durban, 4001, South Africa
| |
Collapse
|
15
|
Abstract
Sphingosine-1-phosphate (S1P) is a lipidic mediator in mammals that functions either as a second messenger or as a ligand. In the latter case, it is transported by its HDL-associated apoM carrier and circulated in blood where it binds to specific S1P receptors on cell membranes and induces downstream reactions. Although S1P signaling pathways are essential for many biological processes, they are poorly understood at the molecular level. Here, the solved crystal structures of the S1P1 receptor were used to evaluate molecular dynamics (MD) simulations to generate greater detailed molecular insights into the mechanism of S1P signaling. The MD simulations provided observations at the coarse-grained and atomic levels indicating that S1P may access the receptor binding pocket directly from solvents. Lifting of the bulky N-terminal cap region of the receptor precedes initial S1P binding. Glu1213.29 guides S1P penetration, and together with Arg2927.34 is responsible for the stabilization of S1P in the binding pocket, which is consistent with experimental predictions. The complete binding of S1P is followed by receptor activation, wherein Trp2696.48 moves toward the transmembrane helix (TM) 7, resulting in the formation of an enhanced hydrogen bond network in the lower region of TM7. The distance between TM3 and TM6 is subsequently increased, resulting in the opening of the intracellular binding pocket that enables G protein binding. Further analysis of the force distribution network in the receptor yielded a detailed molecular understanding of the signal transmission network that is activated upon agonist binding.
Collapse
|
16
|
Pandey A, LeBlanc DM, Parmar HB, Phạm TTT, Sarker M, Xu L, Duncan R, Liu XQ, Rainey JK. Structure, amphipathy, and topology of the membrane-proximal helix 8 influence apelin receptor plasma membrane localization. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1861:183036. [PMID: 31394100 DOI: 10.1016/j.bbamem.2019.183036] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 07/08/2019] [Accepted: 08/02/2019] [Indexed: 12/11/2022]
Abstract
G-protein coupled receptors (GPCRs) typically have an amphipathic helix ("helix 8") immediately C-terminal to the transmembrane helical bundle. To date, a number of functional roles have been associated with GPCR helix 8 segments, but structure-function analysis for this region remains limited. Here, we examine helix 8 of the apelin receptor (AR or APJ), a class A GPCR with wide physiological and pathophysiological relevance. The 71 residue C-terminal tail of the AR is primarily intrinsically disordered, with a detergent micelle-induced increase in helical character. This helicity was localized to the helix 8 region, in good agreement with the recent AR crystal structure. A series of helix 8 mutants were made to reduce helicity, remove amphipathy, or flip the hydrophobic and hydrophilic faces. Each mutant AR was tested both biophysically, in the isolated C-terminal tail, and functionally in HEK 293 T cells, for full-length AR. In all instances, micelle interactions were maintained, and steady-state AR expression was efficient. However, removal of amphipathy or helical character led to a significant decrease in cell surface localization. Flipping of helix 8 amphipathic topology restored cell surface localization to some degree, but still was significantly reduced relative to wild-type. Structural integrity, amphipathy to drive membrane association, and correct topology of helix 8 membrane association all thus appear important for cell surface localization of the AR. This behavior correlates well to GPCR C-terminal tail sequence motifs, implying that these serve to specify key topological features of helix 8 and its proximity to the transmembrane domain.
Collapse
Affiliation(s)
- Aditya Pandey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Danielle M LeBlanc
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Hirendrasinh B Parmar
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Trần Thanh Tâm Phạm
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Muzaddid Sarker
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Lingling Xu
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Roy Duncan
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Xiang-Qin Liu
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada; Department of Chemistry, Dalhousie University, Halifax, Nova Scotia B3H 4R2, Canada.
| |
Collapse
|
17
|
Zhang M, Wu G. Mechanisms of the anterograde trafficking of GPCRs: Regulation of AT1R transport by interacting proteins and motifs. Traffic 2018; 20:110-120. [PMID: 30426616 DOI: 10.1111/tra.12624] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 10/29/2018] [Accepted: 11/08/2018] [Indexed: 12/11/2022]
Abstract
Anterograde cell surface transport of nascent G protein-coupled receptors (GPCRs) en route from the endoplasmic reticulum (ER) through the Golgi apparatus represents a crucial checkpoint to control the amount of the receptors at the functional destination and the strength of receptor activation-elicited cellular responses. However, as compared with extensively studied internalization and recycling processes, the molecular mechanisms of cell surface trafficking of GPCRs are relatively less defined. Here, we will review the current advances in understanding the ER-Golgi-cell surface transport of GPCRs and use angiotensin II type 1 receptor as a representative GPCR to discuss emerging roles of receptor-interacting proteins and specific motifs embedded within the receptors in controlling the forward traffic of GPCRs along the biosynthetic pathway.
Collapse
Affiliation(s)
- Maoxiang Zhang
- Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Augusta University, Augusta, Georgia
| |
Collapse
|
18
|
Arginine 313 of the putative 8th helix mediates Gα q/14 coupling of human CC chemokine receptors CCR2a and CCR2b. Cell Signal 2018; 53:170-183. [PMID: 30321592 DOI: 10.1016/j.cellsig.2018.10.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Revised: 10/08/2018] [Accepted: 10/10/2018] [Indexed: 01/29/2023]
Abstract
In man, two CC chemokine receptor isoforms, CCR2a and CCR2b, are present that belong to the rhodopsin-like G protein-coupled receptor family, and couple to Gi and Gq family members. The CCR2 receptors are known to regulate canonical functions of chemokines such as directed migration of leukocytes, and to potentially control non-canonical functions such as differentiation, proliferation, and gene transcription of immune and non-immune cells. We recently reported on the activation of phospholipase C isoenzymes and RhoA GTPases by coupling of the two CCR2 receptors to members of the Gq family, in particular Gαq and Gα14. So far little is known about the structural requirements for the CCR2/Gq/14 interaction. Interestingly, the CCR2 receptor isoforms are identical up to arginine 313 (R313) that is part of the putative 8th helix in CCR2 receptors, and the 8th helix has been implicated in the interaction of rhodopsin-like G protein-coupled receptors with Gαq. In the present work we describe that the 8th helix of both CCR2a and CCR2b is critically involved in selectively activating Gαq/14-regulated signaling. Refined analysis using various CCR2a and CCR2b mutants and analyzing their cellular signaling, e.g. ligand-dependent (i) activation of phospholipase C isoenzymes, (ii) stimulation of serum response factor-mediated gene transcription, (iii) activation of mitogen-activated protein kinases, (iv) internalization, and (v) changes in intracellular calcium concentrations, identified arginine 313 within the amino terminal portion of helix 8 to play a role for the agonist-mediated conformational changes and the formation of a Gαq/14 binding surface. We show that R313 determines Gαq/14 protein-dependent but not Gi protein-dependent cellular signaling, and plays no role in Gq/Gi-independent receptor internalization, indicating a role of R313 in biased signaling of CCR2 receptors.
Collapse
|
19
|
Wang L, Yao D, Deepak RNVK, Liu H, Xiao Q, Fan H, Gong W, Wei Z, Zhang C. Structures of the Human PGD 2 Receptor CRTH2 Reveal Novel Mechanisms for Ligand Recognition. Mol Cell 2018; 72:48-59.e4. [PMID: 30220562 DOI: 10.1016/j.molcel.2018.08.009] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 07/25/2018] [Accepted: 08/06/2018] [Indexed: 12/31/2022]
Abstract
The signaling of prostaglandin D2 (PGD2) through G-protein-coupled receptor (GPCR) CRTH2 is a major pathway in type 2 inflammation. Compelling evidence suggests the therapeutic benefits of blocking CRTH2 signaling in many inflammatory disorders. Currently, a number of CRTH2 antagonists are under clinical investigation, and one compound, fevipiprant, has advanced to phase 3 clinical trials for asthma. Here, we present the crystal structures of human CRTH2 with two antagonists, fevipiprant and CAY10471. The structures, together with docking and ligand-binding data, reveal a semi-occluded pocket covered by a well-structured amino terminus and different binding modes of chemically diverse CRTH2 antagonists. Structural analysis suggests a ligand entry port and a binding process that is facilitated by opposite charge attraction for PGD2, which differs significantly from the binding pose and binding environment of lysophospholipids and endocannabinoids, revealing a new mechanism for lipid recognition by GPCRs.
Collapse
Affiliation(s)
- Lei Wang
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Dandan Yao
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Chinese Academy of Sciences, Beijing 100049, China
| | - R N V Krishna Deepak
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A(∗)STAR), Singapore 138671, Singapore
| | - Heng Liu
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Qingpin Xiao
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA; Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China
| | - Hao Fan
- Bioinformatics Institute (BII), Agency for Science, Technology and Research (A(∗)STAR), Singapore 138671, Singapore
| | - Weimin Gong
- Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China; Hefei National Research Center for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230027, China
| | - Zhiyi Wei
- Department of Biology, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
| | - Cheng Zhang
- Department of Pharmacology and Chemical Biology, School of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA.
| |
Collapse
|
20
|
Lee TH, Hirst DJ, Kulkarni K, Del Borgo MP, Aguilar MI. Exploring Molecular-Biomembrane Interactions with Surface Plasmon Resonance and Dual Polarization Interferometry Technology: Expanding the Spotlight onto Biomembrane Structure. Chem Rev 2018; 118:5392-5487. [PMID: 29793341 DOI: 10.1021/acs.chemrev.7b00729] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The molecular analysis of biomolecular-membrane interactions is central to understanding most cellular systems but has emerged as a complex technical challenge given the complexities of membrane structure and composition across all living cells. We present a review of the application of surface plasmon resonance and dual polarization interferometry-based biosensors to the study of biomembrane-based systems using both planar mono- or bilayers or liposomes. We first describe the optical principals and instrumentation of surface plasmon resonance, including both linear and extraordinary transmission modes and dual polarization interferometry. We then describe the wide range of model membrane systems that have been developed for deposition on the chips surfaces that include planar, polymer cushioned, tethered bilayers, and liposomes. This is followed by a description of the different chemical immobilization or physisorption techniques. The application of this broad range of engineered membrane surfaces to biomolecular-membrane interactions is then overviewed and how the information obtained using these techniques enhance our molecular understanding of membrane-mediated peptide and protein function. We first discuss experiments where SPR alone has been used to characterize membrane binding and describe how these studies yielded novel insight into the molecular events associated with membrane interactions and how they provided a significant impetus to more recent studies that focus on coincident membrane structure changes during binding of peptides and proteins. We then discuss the emerging limitations of not monitoring the effects on membrane structure and how SPR data can be combined with DPI to provide significant new information on how a membrane responds to the binding of peptides and proteins.
Collapse
Affiliation(s)
- Tzong-Hsien Lee
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute , Monash University , Clayton , VIC 3800 , Australia
| | - Daniel J Hirst
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute , Monash University , Clayton , VIC 3800 , Australia
| | - Ketav Kulkarni
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute , Monash University , Clayton , VIC 3800 , Australia
| | - Mark P Del Borgo
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute , Monash University , Clayton , VIC 3800 , Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry and Molecular Biology and Biomedicine Discovery Institute , Monash University , Clayton , VIC 3800 , Australia
| |
Collapse
|
21
|
Abstract
Sensing external signals and transducing these into intracellular responses requires a molecular signaling system that is crucial for every living organism. Two important eukaryotic signal transduction pathways that are often interlinked are G-protein signaling and phospholipid signaling. Heterotrimeric G-protein subunits activated by G-protein-coupled receptors (GPCRs) are typical stimulators of phospholipid signaling enzymes such as phosphatidylinositol phosphate kinases (PIPKs) or phospholipase C (PLC). However, a direct connection between the two pathways likely exists in oomycetes and slime molds, as they possess a unique class of GPCRs that have a PIPK as an accessory domain. In principle, these so-called GPCR-PIPKs have the capacity of perceiving an external signal (via the GPCR domain) that, via PIPK, directly activates downstream phospholipid signaling. Here we reveal the sporadic occurrence of GPCR-PIPKs in all eukaryotic supergroups, except for plants. Notably, all species having GPCR-PIPKs are unicellular microorganisms that favor aquatic environments. Phylogenetic analysis revealed that GPCR-PIPKs are likely ancestral to eukaryotes and significantly expanded in the last common ancestor of oomycetes. In addition to GPCR-PIPKs, we identified five hitherto-unknown classes of GPCRs with accessory domains, four of which are universal players in signal transduction. Similarly to GPCR-PIPKs, this enables a direct coupling between extracellular sensing and downstream signaling. Overall, our findings point to an ancestral signaling system in eukaryotes where GPCR-mediated sensing is directly linked to downstream responses. G-protein-coupled receptors (GPCRs) are central sensors that activate eukaryotic signaling and are the primary targets of human drugs. In this report, we provide evidence for the widespread though limited presence of a novel class of GPCRs in a variety of unicellular eukaryotes. These include free-living organisms and organisms that are pathogenic for plants, animals, and humans. The novel GPCRs have a C-terminal phospholipid kinase domain, pointing to a direct link between sensing external signals via GPCRs and downstream intracellular phospholipid signaling. Genes encoding these receptors were likely present in the last common eukaryotic ancestor and were lost during the evolution of higher eukaryotes. We further describe five other types of GPCRs with a catalytic accessory domain, the so-called GPCR-bigrams, four of which may potentially have a role in signaling. These findings shed new light onto signal transduction in microorganisms and provide evidence for alternative eukaryotic signaling pathways.
Collapse
|
22
|
Tréfier A, Musnier A, Landomiel F, Bourquard T, Boulo T, Ayoub MA, León K, Bruneau G, Chevalier M, Durand G, Blache MC, Inoue A, Fontaine J, Gauthier C, Tesseraud S, Reiter E, Poupon A, Crépieux P. G protein-dependent signaling triggers a β-arrestin-scaffolded p70S6K/ rpS6 module that controls 5'TOP mRNA translation. FASEB J 2018; 32:1154-1169. [PMID: 29084767 DOI: 10.1096/fj.201700763r] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Many interaction partners of β-arrestins intervene in the control of mRNA translation. However, how β-arrestins regulate this cellular process has been poorly explored. In this study, we show that β-arrestins constitutively assemble a p70S6K/ribosomal protein S6 (rpS6) complex in HEK293 cells and in primary Sertoli cells of the testis. We demonstrate that this interaction is direct, and experimentally validate the interaction interface between β-arrestin 1 and p70S6K predicted by our docking algorithm. Like most GPCRs, the biological function of follicle-stimulating hormone receptor (FSHR) is transduced by G proteins and β-arrestins. Upon follicle-stimulating hormone (FSH) stimulation, activation of G protein-dependent signaling enhances p70S6K activity within the β-arrestin/p70S6K/rpS6 preassembled complex, which is not recruited to the FSHR. In agreement, FSH-induced rpS6 phosphorylation within the β-arrestin scaffold was decreased in cells depleted of Gαs. Integration of the cooperative action of β-arrestin and G proteins led to the translation of 5' oligopyrimidine track mRNA with high efficacy within minutes of FSH input. Hence, this work highlights new relationships between G proteins and β-arrestins when acting cooperatively on a common signaling pathway, contrasting with their previously shown parallel action on the ERK MAP kinase pathway. In addition, this study provides insights into how GPCR can exert trophic effects in the cell.-Tréfier, A., Musnier, A., Landomiel, F., Bourquard, T., Boulo, T., Ayoub, M. A., León, K., Bruneau, G., Chevalier, M., Durand, G., Blache, M.-C., Inoue, A., Fontaine, J., Gauthier, C., Tesseraud, S., Reiter, E., Poupon, A., Crépieux, P. G protein-dependent signaling triggers a β-arrestin-scaffolded p70S6K/ rpS6 module that controls 5'TOP mRNA translation.
Collapse
Affiliation(s)
- Aurélie Tréfier
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Astrid Musnier
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Flavie Landomiel
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Thomas Bourquard
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Thomas Boulo
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Mohammed Akli Ayoub
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France.,Biology Department, College of Science, United Arab Emirates University, Al Ain, United Arab Emirates
| | - Kelly León
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Gilles Bruneau
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Manon Chevalier
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Guillaume Durand
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Marie-Claire Blache
- Plateau d'Imagerie Cellulaire (PIC), Unité Mixte de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan; and
| | - Joël Fontaine
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Christophe Gauthier
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Sophie Tesseraud
- Metabolism of Birds, Quality and Adaptation (MOQA) Group, Unité de Recherches 83, Unité de Recherches Avicoles, Institut National de la Recherche Agronomique (INRA), Nouzilly, France
| | - Eric Reiter
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Anne Poupon
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| | - Pascale Crépieux
- Biology and Bioinformatics of Signaling Systems (BIOS) Group, Unité Mixtes de Recherche 85, Unité Physiologie de la Reproduction et des Comportements, Institut National de la Recherche Agronomique (INRA), Nouzilly, France.,Centre National de la Recherche Scientifique (CNRS), Unité Mixte de Recherche 7247, Nouzilly, France.,Université François Rabelais, Tours, France.,Institut Français du Cheval et de l'Équitation (IFCE), Nouzilly, France
| |
Collapse
|
23
|
Abstract
Apelin and apela (ELABELA/ELA/Toddler) are two peptide ligands for a class A G-protein-coupled receptor named the apelin receptor (AR/APJ/APLNR). Ligand-AR interactions have been implicated in regulation of the adipoinsular axis, cardiovascular system, and central nervous system alongside pathological processes. Each ligand may be processed into a variety of bioactive isoforms endogenously, with apelin ranging from 13 to 55 amino acids and apela from 11 to 32, typically being cleaved C-terminal to dibasic proprotein convertase cleavage sites. The C-terminal region of the respective precursor protein is retained and is responsible for receptor binding and subsequent activation. Interestingly, both apelin and apela exhibit isoform-dependent variability in potency and efficacy under various physiological and pathological conditions, but most studies focus on a single isoform. Biophysical behavior and structural properties of apelin and apela isoforms show strong correlations with functional studies, with key motifs now well determined for apelin. Unlike its ligands, the AR has been relatively difficult to characterize by biophysical techniques, with most characterization to date being focused on effects of mutagenesis. This situation may improve following a recently reported AR crystal structure, but there are still barriers to overcome in terms of comprehensive biophysical study. In this review, we summarize the three components of the apelinergic system in terms of structure-function correlation, with a particular focus on isoform-dependent properties, underlining the potential for regulation of the system through multiple endogenous ligands and isoforms, isoform-dependent pharmacological properties, and biological membrane-mediated receptor interaction. © 2018 American Physiological Society. Compr Physiol 8:407-450, 2018.
Collapse
Affiliation(s)
- Kyungsoo Shin
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Calem Kenward
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|
24
|
Ishizuka K, Fujita Y, Kawabata T, Kimura H, Iwayama Y, Inada T, Okahisa Y, Egawa J, Usami M, Kushima I, Uno Y, Okada T, Ikeda M, Aleksic B, Mori D, Someya T, Yoshikawa T, Iwata N, Nakamura H, Yamashita T, Ozaki N. Rare genetic variants in CX3CR1 and their contribution to the increased risk of schizophrenia and autism spectrum disorders. Transl Psychiatry 2017; 7:e1184. [PMID: 28763059 PMCID: PMC5611740 DOI: 10.1038/tp.2017.173] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 05/20/2017] [Accepted: 06/17/2017] [Indexed: 12/20/2022] Open
Abstract
CX3CR1, a G protein-coupled receptor solely expressed by microglia in the brain, has been repeatedly reported to be associated with neurodevelopmental disorders including schizophrenia (SCZ) and autism spectrum disorders (ASD) in transcriptomic and animal studies but not in genetic studies. To address the impacts of variants in CX3CR1 on neurodevelopmental disorders, we conducted coding exon-targeted resequencing of CX3CR1 in 370 Japanese SCZ and 192 ASD patients using next-generation sequencing technology, followed by a genetic association study in a sample comprising 7054 unrelated individuals (2653 SCZ, 574 ASD and 3827 controls). We then performed in silico three-dimensional (3D) structural modeling and in vivo disruption of Akt phosphorylation to determine the impact of the detected variant on CX3CR1-dependent signal transduction. We detected a statistically significant association between the variant Ala55Thr in CX3CR1 with SCZ and ASD phenotypes (odds ratio=8.3, P=0.020). A 3D structural model indicated that Ala55Thr could destabilize the conformation of the CX3CR1 helix 8 and affect its interaction with a heterotrimeric G protein. In vitro functional analysis showed that the CX3CR1-Ala55Thr mutation inhibited cell signaling induced by fractalkine, the ligand for CX3CR1. The combined data suggested that the variant Ala55Thr in CX3CR1 might result in the disruption of CX3CR1 signaling. Our results strengthen the association between microglia-specific genes and neurodevelopmental disorders.
Collapse
Affiliation(s)
- K Ishizuka
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan
| | - Y Fujita
- Department of Molecular Neuroscience,
Osaka University Graduate School of Medicine, Osaka,
Japan
| | - T Kawabata
- Institute for Protein Research, Osaka
University, Osaka, Japan
| | - H Kimura
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan
| | - Y Iwayama
- Laboratory for Molecular Psychiatry,
RIKEN Brain Science Institute, Wako, Japan
| | - T Inada
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan
| | - Y Okahisa
- Department of Neuropsychiatry, Okayama
University Graduate School of Medicine, Dentistry and Pharmaceutical
Sciences, Okayama, Japan
| | - J Egawa
- Department of Psychiatry, Niigata
University Graduate School of Medical and Dental Sciences,
Niigata, Japan
| | - M Usami
- Department of Child and Adolescent
Psychiatry, Kohnodai Hospital, National Center for Global Health and
Medicine, Ichikawa, Japan
| | - I Kushima
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan
| | - Y Uno
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan,Laboratory for Psychiatric and Molecular
Neuroscience, McLean Hospital, Belmont, MA,
USA
| | - T Okada
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan
| | - M Ikeda
- Department of Psychiatry, Fujita Health
University School of Medicine, Toyoake, Japan
| | - B Aleksic
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan,Department of Psychiatry, Nagoya University Graduate School
of Medicine, 65 Tsurumai-cho, Showa-ku,
Nagoya, Aichi
4668550, Japan. E-mail:
| | - D Mori
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan,Brain and Mind Research Center, Nagoya
University, Nagoya, Japan
| | - To Someya
- Department of Psychiatry, Niigata
University Graduate School of Medical and Dental Sciences,
Niigata, Japan
| | - T Yoshikawa
- Laboratory for Molecular Psychiatry,
RIKEN Brain Science Institute, Wako, Japan
| | - N Iwata
- Department of Psychiatry, Fujita Health
University School of Medicine, Toyoake, Japan
| | - H Nakamura
- Institute for Protein Research, Osaka
University, Osaka, Japan
| | - T Yamashita
- Department of Molecular Neuroscience,
Osaka University Graduate School of Medicine, Osaka,
Japan
| | - N Ozaki
- Department of Psychiatry, Nagoya
University Graduate School of Medicine, Nagoya,
Japan
| |
Collapse
|
25
|
Sato T, Kawasaki T, Mine S, Matsumura H. Functional Role of the C-Terminal Amphipathic Helix 8 of Olfactory Receptors and Other G Protein-Coupled Receptors. Int J Mol Sci 2016; 17:ijms17111930. [PMID: 27869740 PMCID: PMC5133925 DOI: 10.3390/ijms17111930] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Revised: 11/09/2016] [Accepted: 11/14/2016] [Indexed: 11/23/2022] Open
Abstract
G protein-coupled receptors (GPCRs) transduce various extracellular signals, such as neurotransmitters, hormones, light, and odorous chemicals, into intracellular signals via G protein activation during neurological, cardiovascular, sensory and reproductive signaling. Common and unique features of interactions between GPCRs and specific G proteins are important for structure-based design of drugs in order to treat GPCR-related diseases. Atomic resolution structures of GPCR complexes with G proteins have revealed shared and extensive interactions between the conserved DRY motif and other residues in transmembrane domains 3 (TM3), 5 and 6, and the target G protein C-terminal region. However, the initial interactions formed between GPCRs and their specific G proteins remain unclear. Alanine scanning mutagenesis of the murine olfactory receptor S6 (mOR-S6) indicated that the N-terminal acidic residue of helix 8 of mOR-S6 is responsible for initial transient and specific interactions with chimeric Gα15_olf, resulting in a response that is 2.2-fold more rapid and 1.7-fold more robust than the interaction with Gα15. Our mutagenesis analysis indicates that the hydrophobic core buried between helix 8 and TM1–2 of mOR-S6 is important for the activation of both Gα15_olf and Gα15. This review focuses on the functional role of the C-terminal amphipathic helix 8 based on several recent GPCR studies.
Collapse
Affiliation(s)
- Takaaki Sato
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorioka, Ikeda, Osaka 563-8577, Japan.
| | - Takashi Kawasaki
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorioka, Ikeda, Osaka 563-8577, Japan.
| | - Shouhei Mine
- Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology, 1-8-31 Midorioka, Ikeda, Osaka 563-8577, Japan.
| | - Hiroyoshi Matsumura
- College of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
| |
Collapse
|
26
|
Karnik SS, Unal H, Kemp JR, Tirupula KC, Eguchi S, Vanderheyden PML, Thomas WG. International Union of Basic and Clinical Pharmacology. XCIX. Angiotensin Receptors: Interpreters of Pathophysiological Angiotensinergic Stimuli [corrected]. Pharmacol Rev 2015; 67:754-819. [PMID: 26315714 PMCID: PMC4630565 DOI: 10.1124/pr.114.010454] [Citation(s) in RCA: 215] [Impact Index Per Article: 23.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The renin angiotensin system (RAS) produced hormone peptides regulate many vital body functions. Dysfunctional signaling by receptors for RAS peptides leads to pathologic states. Nearly half of humanity today would likely benefit from modern drugs targeting these receptors. The receptors for RAS peptides consist of three G-protein-coupled receptors—the angiotensin II type 1 receptor (AT1 receptor), the angiotensin II type 2 receptor (AT2 receptor), the MAS receptor—and a type II trans-membrane zinc protein—the candidate angiotensin IV receptor (AngIV binding site). The prorenin receptor is a relatively new contender for consideration, but is not included here because the role of prorenin receptor as an independent endocrine mediator is presently unclear. The full spectrum of biologic characteristics of these receptors is still evolving, but there is evidence establishing unique roles of each receptor in cardiovascular, hemodynamic, neurologic, renal, and endothelial functions, as well as in cell proliferation, survival, matrix-cell interaction, and inflammation. Therapeutic agents targeted to these receptors are either in active use in clinical intervention of major common diseases or under evaluation for repurposing in many other disorders. Broad-spectrum influence these receptors produce in complex pathophysiological context in our body highlights their role as precise interpreters of distinctive angiotensinergic peptide cues. This review article summarizes findings published in the last 15 years on the structure, pharmacology, signaling, physiology, and disease states related to angiotensin receptors. We also discuss the challenges the pharmacologist presently faces in formally accepting newer members as established angiotensin receptors and emphasize necessary future developments.
Collapse
Affiliation(s)
- Sadashiva S Karnik
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Hamiyet Unal
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Jacqueline R Kemp
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Kalyan C Tirupula
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Satoru Eguchi
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Patrick M L Vanderheyden
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| | - Walter G Thomas
- Department of Molecular Cardiology, Lerner Research Institute of Cleveland Clinic, Cleveland, Ohio (S.S.K., H.U., J.R.K., K.C.T.); Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania (S.E.); Faculty of Sciences and Bioengineering Sciences, Vrije Universiteit Brussel, Brussels, Belgium (P.M.L.V.); and Department of General Physiology, School of Biomedical Sciences, The University of Queensland, Brisbane, Queensland, Australia (W.G.T.)
| |
Collapse
|
27
|
Zhu S, Zhang M, Davis JE, Wu WH, Surrao K, Wang H, Wu G. A single mutation in helix 8 enhances the angiotensin II type 1a receptor transport and signaling. Cell Signal 2015; 27:2371-9. [PMID: 26342563 DOI: 10.1016/j.cellsig.2015.08.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 08/30/2015] [Indexed: 01/01/2023]
Abstract
The amphipathic helix 8 in the membrane-proximal C-terminus is a structurally conserved feature of class A seven transmembrane-spanning G protein-coupled receptors (GPCRs). Mutations of this helical motif often cause receptor misfolding, defective cell surface transport and dysfunction. Surprisingly, we demonstrated here that a single point mutation at Lys308 in helix 8 markedly enhanced the steady-state surface density of the angiotensin II type 1a receptor (AT1aR). Consistent with the enhanced cell surface expression, Lys308 mutation significantly augmented AT1aR-mediated mitogen-activated protein kinase ERK1/2 activation, inositol phosphate production, and vascular smooth muscle cell migration. This mutation also increased the overall expression of AT1aR without altering receptor degradation. More interestingly, Lys308 mutation abolished AT1aR interaction with β-COP, a component of COPI transport vesicles, and impaired AT1aR responsiveness to the inhibition of Rab6 GTPase involved in the Golgi-to-ER retrograde pathway. Furthermore, these functions of Lys308 were largely dependent on its positively charged property. These data reveal previously unappreciated functions of helix 8 and novel mechanisms governing the cell surface transport and function of AT1aR.
Collapse
Affiliation(s)
- Shu Zhu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta GA 30912, United States
| | - Maoxiang Zhang
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta GA 30912, United States
| | - Jason E Davis
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta GA 30912, United States
| | - William H Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta GA 30912, United States
| | - Kristen Surrao
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta GA 30912, United States
| | - Hong Wang
- School of Life Sciences and Technology, Tongji University, 1239 Siping Road, Shanghai, China
| | - Guangyu Wu
- Department of Pharmacology and Toxicology, Medical College of Georgia, Georgia Regents University, 1459 Laney Walker Blvd., Augusta GA 30912, United States.
| |
Collapse
|
28
|
Helix 8 of the angiotensin- II type 1A receptor interacts with phosphatidylinositol phosphates and modulates membrane insertion. Sci Rep 2015; 5:9972. [PMID: 26126083 PMCID: PMC5378882 DOI: 10.1038/srep09972] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2015] [Accepted: 03/26/2015] [Indexed: 11/16/2022] Open
Abstract
The carboxyl-terminus of the type 1 angiotensin II receptor (AT1A) regulates receptor activation/deactivation and the amphipathic Helix 8 within the carboxyl-terminus is a high affinity interaction motif for plasma membrane lipids. We have used dual polarisation interferometry (DPI) to examine the role of phosphatidylinositdes in the specific recognition of Helix 8 in the AT1A receptor. A synthetic peptide corresponding to Leu305 to Lys325 (Helix 8 AT1A) discriminated between PIPs and different charges on lipid membranes. Peptide binding to PtdIns(4)P-containing bilayers caused a dramatic change in the birefringence (a measure of membrane order) of the bilayer. Kinetic modelling showed that PtdIns(4)P is held above the bilayer until the mass of bound peptide reaches a threshold, after which the peptides insert further into the bilayer. This suggests that Helix 8 can respond to the presence of PI(4)P by withdrawing from the bilayer, resulting in a functional conformational change in the receptor.
Collapse
|
29
|
Liu R, Nahon D, le Roy B, Lenselink EB, IJzerman AP. Scanning mutagenesis in a yeast system delineates the role of the NPxxY(x)(5,6)F motif and helix 8 of the adenosine A(2B) receptor in G protein coupling. Biochem Pharmacol 2015; 95:290-300. [PMID: 25896847 DOI: 10.1016/j.bcp.2015.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Accepted: 04/10/2015] [Indexed: 01/05/2023]
Abstract
The adenosine receptor subfamily includes four subtypes: the A1, A2A, A2B and A3 receptors, which all belong to the superfamily of G protein-coupled receptors (GPCRs). The adenosine A2B receptor is the least investigated of the adenosine receptors, and the molecular mechanisms of its activation have hardly been explored. We used a single-GPCR-one-G protein yeast screening method in combination with mutagenesis studies, molecular modeling and bio-informatics to investigate the importance of the different amino acid residues of the NPxxY(x)6F motif and helix 8 in the human adenosine A2B receptor (hA2BR) activation. A scanning mutagenesis protocol was employed, yielding 11 single mutations and one double mutation of the NPxxY(x)6F motif and 16 single mutations of helix 8. The amino acid residues P287(7.50), Y290(7.53), R293(7.56) and I304(8.57) were found to be essential, since mutation of these amino acid residues to alanine led to a complete loss of function. Western blot analysis showed that mutant receptor R293(7.56)A was not expressed, whereas the other proteins were. Amino acid residues that are also important in receptor activation are: N286(7.49), V289(7.52), Y292(7.55), N294(8.47), F297(8.50), R298(8.51), H302(8.55) and R307(8.60). The mutation Y290(7.53)F lost 50% of efficacy, while F297(8.50)A behaved similar to wild type receptor. The double mutation, Y290(7.53)F/F297(8.50)Y, lost around 70% of efficacy and displayed a lower potency for the reference agonist 5'-(N-ethylcarboxamido)adenosine (NECA). This study provides new insight into the molecular interplay and impact of TM7 and helix 8 for hA2B receptor activation, which may be extrapolated to other adenosine receptors and possibly to other GPCRs.
Collapse
Affiliation(s)
- Rongfang Liu
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Dennis Nahon
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Beau le Roy
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Eelke B Lenselink
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands
| | - Adriaan P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research, Leiden University, P.O. Box 9502, 2300 RA Leiden, The Netherlands.
| |
Collapse
|
30
|
Dunn HA, Ferguson SSG. PDZ Protein Regulation of G Protein–Coupled Receptor Trafficking and Signaling Pathways. Mol Pharmacol 2015; 88:624-39. [DOI: 10.1124/mol.115.098509] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 03/25/2015] [Indexed: 01/03/2023] Open
|
31
|
Karpinsky-Semper D, Tayou J, Levay K, Schuchardt BJ, Bhat V, Volmar CH, Farooq A, Slepak VZ. Helix 8 and the i3 loop of the muscarinic M3 receptor are crucial sites for its regulation by the Gβ5-RGS7 complex. Biochemistry 2015; 54:1077-88. [PMID: 25551629 PMCID: PMC4318586 DOI: 10.1021/bi500980d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
The muscarinic M3 receptor (M3R)
is a Gq-coupled receptor and is
known to interact with many intracellular regulatory proteins. One
of these molecules is Gβ5-RGS7, the permanently associated heterodimer
of G protein β-subunit Gβ5 and RGS7, a regulator of G
protein signaling. Gβ5-RGS7 can attenuate M3R-stimulated release
of Ca2+ from intracellular stores or enhance the influx
of Ca2+ across the plasma membrane. Here we show that deletion
of amino acids 304–345 from the central portion of the i3 loop
renders M3R insensitive to regulation by Gβ5-RGS7. In addition
to the i3 loop, interaction of M3R with Gβ5-RGS7 requires helix
8. According to circular dichroism spectroscopy, the peptide corresponding
to amino acids 548–567 in the C-terminus of M3R assumes an
α-helical conformation. Substitution of Thr553 and Leu558 with
Pro residues disrupts this α-helix and abolished binding to
Gβ5-RGS7. Introduction of the double Pro substitution into full-length
M3R (M3RTP/LP) prevents trafficking of the receptor to
the cell surface. Using atropine or other antagonists as pharmacologic
chaperones, we were able to increase the level of surface expression
of the TP/LP mutant to levels comparable to that of wild-type M3R.
However, M3R-stimulated calcium signaling is still severely compromised.
These results show that the interaction of M3R with Gβ5-RGS7
requires helix 8 and the central portion of the i3 loop.
Collapse
Affiliation(s)
- Darla Karpinsky-Semper
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine , 1600 NW 10th Avenue, RMSB6024A, Miami, Florida 33136, United States
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Esaki K, Yoshinaga S, Tsuji T, Toda E, Terashima Y, Saitoh T, Kohda D, Kohno T, Osawa M, Ueda T, Shimada I, Matsushima K, Terasawa H. Structural basis for the binding of the membrane-proximal C-terminal region of chemokine receptor CCR2 with the cytosolic regulator FROUNT. FEBS J 2014; 281:5552-66. [DOI: 10.1111/febs.13096] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 09/09/2014] [Accepted: 09/30/2014] [Indexed: 12/14/2022]
Affiliation(s)
- Kaori Esaki
- Department of Structural BioImaging; Faculty of Life Sciences; Kumamoto University; Kumamoto Japan
| | - Sosuke Yoshinaga
- Department of Structural BioImaging; Faculty of Life Sciences; Kumamoto University; Kumamoto Japan
| | - Tatsuichiro Tsuji
- Department of Structural BioImaging; Faculty of Life Sciences; Kumamoto University; Kumamoto Japan
| | - Etsuko Toda
- Department of Molecular Preventive Medicine; Graduate School of Medicine; The University of Tokyo; Tokyo Japan
| | - Yuya Terashima
- Department of Molecular Preventive Medicine; Graduate School of Medicine; The University of Tokyo; Tokyo Japan
| | - Takashi Saitoh
- Division of Structural Biology; Medical Institute of Bioregulation; Kyushu University; Fukuoka Japan
| | - Daisuke Kohda
- Division of Structural Biology; Medical Institute of Bioregulation; Kyushu University; Fukuoka Japan
| | - Toshiyuki Kohno
- Department of Biochemistry; Kitasato University School of Medicine; Kanagawa Japan
| | - Masanori Osawa
- Division of Physical Chemistry; Graduate School of Pharmaceutical Sciences; The University of Tokyo; Tokyo Japan
| | - Takumi Ueda
- Division of Physical Chemistry; Graduate School of Pharmaceutical Sciences; The University of Tokyo; Tokyo Japan
| | - Ichio Shimada
- Division of Physical Chemistry; Graduate School of Pharmaceutical Sciences; The University of Tokyo; Tokyo Japan
| | - Kouji Matsushima
- Department of Molecular Preventive Medicine; Graduate School of Medicine; The University of Tokyo; Tokyo Japan
| | - Hiroaki Terasawa
- Department of Structural BioImaging; Faculty of Life Sciences; Kumamoto University; Kumamoto Japan
| |
Collapse
|
33
|
Structure of signaling-competent neurotensin receptor 1 obtained by directed evolution in Escherichia coli. Proc Natl Acad Sci U S A 2014; 111:E655-62. [PMID: 24453215 DOI: 10.1073/pnas.1317903111] [Citation(s) in RCA: 172] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Crystallography has advanced our understanding of G protein-coupled receptors, but low expression levels and instability in solution have limited structural insights to very few selected members of this large protein family. Using neurotensin receptor 1 (NTR1) as a proof of principle, we show that two directed evolution technologies that we recently developed have the potential to overcome these problems. We purified three neurotensin-bound NTR1 variants from Escherichia coli and determined their X-ray structures at up to 2.75 Å resolution using vapor diffusion crystallization experiments. A crystallized construct was pharmacologically characterized and exhibited ligand-dependent signaling, internalization, and wild-type-like agonist and antagonist affinities. Our structures are fully consistent with all biochemically defined ligand-contacting residues, and they represent an inactive NTR1 state at the cytosolic side. They exhibit significant differences to a previously determined NTR1 structure (Protein Data Bank ID code 4GRV) in the ligand-binding pocket and by the presence of the amphipathic helix 8. A comparison of helix 8 stability determinants between NTR1 and other crystallized G protein-coupled receptors suggests that the occupancy of the canonical position of the amphipathic helix is reduced to various extents in many receptors, and we have elucidated the sequence determinants for a stable helix 8. Our analysis also provides a structural rationale for the long-known effects of C-terminal palmitoylation reactions on G protein-coupled receptor signaling, receptor maturation, and desensitization.
Collapse
|
34
|
O'Carroll AM, Lolait SJ, Harris LE, Pope GR. The apelin receptor APJ: journey from an orphan to a multifaceted regulator of homeostasis. J Endocrinol 2013; 219:R13-35. [PMID: 23943882 DOI: 10.1530/joe-13-0227] [Citation(s) in RCA: 246] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The apelin receptor (APJ; gene symbol APLNR) is a member of the G protein-coupled receptor gene family. Neural gene expression patterns of APJ, and its cognate ligand apelin, in the brain implicate the apelinergic system in the regulation of a number of physiological processes. APJ and apelin are highly expressed in the hypothalamo-neurohypophysial system, which regulates fluid homeostasis, in the hypothalamic-pituitary-adrenal axis, which controls the neuroendocrine response to stress, and in the forebrain and lower brainstem regions, which are involved in cardiovascular function. Recently, apelin, synthesised and secreted by adipocytes, has been described as a beneficial adipokine related to obesity, and there is growing awareness of a potential role for apelin and APJ in glucose and energy metabolism. In this review we provide a comprehensive overview of the structure, expression pattern and regulation of apelin and its receptor, as well as the main second messengers and signalling proteins activated by apelin. We also highlight the physiological and pathological roles that support this system as a novel therapeutic target for pharmacological intervention in treating conditions related to altered water balance, stress-induced disorders such as anxiety and depression, and cardiovascular and metabolic disorders.
Collapse
Affiliation(s)
- Anne-Marie O'Carroll
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol BS1 3NY, UK
| | | | | | | |
Collapse
|
35
|
Structure of the C-terminal region of the Frizzled receptor 1 in detergent micelles. Molecules 2013; 18:8579-90. [PMID: 23881048 PMCID: PMC6269726 DOI: 10.3390/molecules18078579] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 07/18/2013] [Accepted: 07/18/2013] [Indexed: 12/13/2022] Open
Abstract
The C-terminal domains of the Frizzleds (FZDs) contain a short conserved motif (KTXXXW). It has been demonstrated that FZDs interacted with the PDZ domain of the cytoplasmic proteins such as Dishevelled through this motif and mutations in this motif disrupted Wnt/β-catenin signaling. We carried out structural studies for a peptide derived from the C-terminal domain of the FZD1 in different solvents using circular dichroism and solution NMR spectroscopy. Our results showed that this domain was unstructured in an aqueous solution and formed a helical structure in detergent micelles. Fluorescence studies suggested that the tryptophan residue (W630) in the motif interacted with micelles. The solution structure of the peptide in sodium dodecyl sulfate micelles was determined and an amphipathic helix was identified. This helix may have similar function to the helix 8 of other G protein-coupled receptors.
Collapse
|
36
|
Klos A, Wende E, Wareham KJ, Monk PN. International Union of Basic and Clinical Pharmacology. [corrected]. LXXXVII. Complement peptide C5a, C4a, and C3a receptors. Pharmacol Rev 2013; 65:500-43. [PMID: 23383423 DOI: 10.1124/pr.111.005223] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
The activation of the complement cascade, a cornerstone of the innate immune response, produces a number of small (74-77 amino acid) fragments, originally termed anaphylatoxins, that are potent chemoattractants and secretagogues that act on a wide variety of cell types. These fragments, C5a, C4a, and C3a, participate at all levels of the immune response and are also involved in other processes such as neural development and organ regeneration. Their primary function, however, is in inflammation, so they are important targets for the development of antiinflammatory therapies. Only three receptors for complement peptides have been found, but there are no satisfactory antagonists as yet, despite intensive investigation. In humans, there is a single receptor for C3a (C3a receptor), no known receptor for C4a, and two receptors for C5a (C5a₁ receptor and C5a₂ receptor). The most recently characterized receptor, the C5a₂ receptor (previously known as C5L2 or GPR77), has been regarded as a passive binding protein, but signaling activities are now ascribed to it, so we propose that it be formally identified as a receptor and be given a name to reflect this. Here, we describe the complex biology of the complement peptides, introduce a new suggested nomenclature, and review our current knowledge of receptor pharmacology.
Collapse
Affiliation(s)
- Andreas Klos
- Department for Medical Microbiology, Medical School Hannover, Hannover, Germany
| | | | | | | |
Collapse
|
37
|
Walther C, Lotze J, Beck-Sickinger AG, Mörl K. The anterograde transport of the human neuropeptide Y2 receptor is regulated by a subtype specific mechanism mediated by the C-terminus. Neuropeptides 2012; 46:335-43. [PMID: 23020974 DOI: 10.1016/j.npep.2012.08.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/24/2012] [Accepted: 08/28/2012] [Indexed: 02/06/2023]
Abstract
The export of newly synthesized proteins, including G protein-coupled receptors (GPCR), from the endoplasmic reticulum (ER) and further transport to the plasma membrane is a tightly regulated process. ER export and subsequent cell surface targeting of GPCR is initially mediated through COPII-coated vesicles. It is governed by specific amino acid sequences located in extracellular as well as intracellular receptor domains, for example in the C-terminus (CT) of the receptor. Herein, we determined the role of the CT in the anterograde transport of the human neuropeptide Y receptor (hYR) type 2. We identified a short sequence motif in the membrane proximal CT: Y(x)(3)F(x)(3)F in the region of the putative 8th helix has a critical functional relevance for the anterograde transport of hY(2)R, since its deletion leads to accumulation of the receptor in the ER. It is sequence and position specific. Furthermore we identified a distinct role of C-terminal sequences in hY(1)R, hY(2)R, hY(4)R and hY(5)R. Regulation of hY(5)R export is regulated by a different mechanism as compared to hY(2)R. Different sequence elements with respect to function and localization are involved as demonstrated by the construction of a hY(2)/hY(5) receptor chimera and a noneffective deletion in the region of helix eight in the hY(5)R. In contrast to hY(2)R, deletion of the corresponding helical segment F(x)(3)L(x)(3)F has no influence on anterograde transport of hY(1)R, whereas deletion of F(x)(3)I(x)(3)V in hY(4)R restrains the receptor to the Golgi apparatus. Interestingly this pattern is not mirrored by repression of COPII vesicle transport by Sar1[H79G] overexpression. Whereas the 8th helix is involved before or at the level of Sar1 dependent export pathways in the ER for the hY(2)R, in hY(4)R helix eight is involved at later stages of anterograde transport.
Collapse
Affiliation(s)
- Cornelia Walther
- Institute of Biochemistry, Faculty of Biosciences, Pharmacy and Psychology, Universität Leipzig, Germany
| | | | | | | |
Collapse
|
38
|
G Protein-Coupled Receptors. Mol Pharmacol 2012. [DOI: 10.1002/9781118451908.ch3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
|
39
|
Pedersen SL, Bhatia VK, Jurt S, Paulsson JF, Pedersen MH, Jorgensen R, Holst B, Stamou D, Vrang N, Zerbe O, Jensen KJ. Improving membrane binding as a design strategy for amphipathic peptide hormones: 2-helix variants of PYY3-36. J Pept Sci 2012; 18:579-87. [DOI: 10.1002/psc.2436] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 06/06/2012] [Indexed: 12/20/2022]
Affiliation(s)
- Søren L. Pedersen
- Department of Chemistry, Faculty of Science; University of Copenhagen; Thorvaldsensvej 40 1871 Frederiksberg C Denmark
- The Lundbeck Foundation Center for Biomembranes in Nanomedicine; Unversity of Copenhagen; Denmark
| | - Vikram K. Bhatia
- Faculty of Health Sciences; University of Copenhagen; Blegdamsvej 3B 2200 Copenhagen N Denmark
- Novozymes A/S; Bagsvaerd Denmark
| | - Simon Jurt
- Institute of Organic Chemistry; University of Zurich; Winterthurerstrasse 190 CH 8057 Zurich Switzerland
| | | | - Maria H. Pedersen
- Department of Chemistry, Faculty of Science; University of Copenhagen; Thorvaldsensvej 40 1871 Frederiksberg C Denmark
| | | | - Birgitte Holst
- Faculty of Health Sciences; University of Copenhagen; Blegdamsvej 3B 2200 Copenhagen N Denmark
| | - Dimitrios Stamou
- Department of Chemistry, Faculty of Science; University of Copenhagen; Thorvaldsensvej 40 1871 Frederiksberg C Denmark
- The Lundbeck Foundation Center for Biomembranes in Nanomedicine; Unversity of Copenhagen; Denmark
| | - Niels Vrang
- gubra Aps; Agern Allé 1 2970 Hørsholm Denmark
| | - Oliver Zerbe
- Institute of Organic Chemistry; University of Zurich; Winterthurerstrasse 190 CH 8057 Zurich Switzerland
| | - Knud J. Jensen
- Department of Chemistry, Faculty of Science; University of Copenhagen; Thorvaldsensvej 40 1871 Frederiksberg C Denmark
- The Lundbeck Foundation Center for Biomembranes in Nanomedicine; Unversity of Copenhagen; Denmark
| |
Collapse
|
40
|
Hamamoto A, Horikawa M, Saho T, Saito Y. Mutation of Phe318 within the NPxxY(x)(5,6)F motif in melanin-concentrating hormone receptor 1 results in an efficient signaling activity. Front Endocrinol (Lausanne) 2012; 3:147. [PMID: 23233849 PMCID: PMC3515998 DOI: 10.3389/fendo.2012.00147] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2012] [Accepted: 11/08/2012] [Indexed: 11/13/2022] Open
Abstract
Melanin-concentrating hormone receptor 1 (MCHR1) is a G-protein-coupled receptor (GPCR) that plays an important role in feeding by coupling to Gα(q)- and Gα(i)-mediated signal transduction pathways. To interrogate the molecular basis for MCHR1 activation, we analyzed the effect of a series of site-directed mutations on rat MCHR1 function. In the highly conserved NPxxY(x)(5,6)F domain of GPCRs, the phenylalanine residue is involved in structural constraints; replacement with alanine generally leads to impaired/lost GPCR function. However, Phe-to-Ala (F318A) mutation in MCHR1 had no significant effect on the level of cell surface expression and receptor signaling. By analyzing a further series of mutants, we found that Phe-to-Lys substitution (F318K) caused the most significant reduction in the EC(50) value of MCH for calcium mobilization without affecting receptor expression at the cell surface. Interestingly, GTPγS-binding, which monitors Gα(i) activation, was not modulated by F318K. Our results, combined with computer modeling, provide new insight into the role of Phe in the NPxxY(x)(5,6)F motif as a structurally critical site for receptor dynamics and a determinant of Gα protein interaction.
Collapse
Affiliation(s)
- Akie Hamamoto
- Graduate School of Integrated Arts and Sciences, Hiroshima UniversityHiroshima, Japan
| | - Manabu Horikawa
- Bioorganic Research Institute, Suntory Foundation for Life SciencesOsaka, Japan
| | - Tomoko Saho
- Graduate School of Integrated Arts and Sciences, Hiroshima UniversityHiroshima, Japan
| | - Yumiko Saito
- Graduate School of Integrated Arts and Sciences, Hiroshima UniversityHiroshima, Japan
- *Correspondence: Yumiko Saito, Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-hiroshima, Hiroshima 739-8521, Japan. e-mail:
| |
Collapse
|
41
|
Hazell GG, Hindmarch CC, Pope GR, Roper JA, Lightman SL, Murphy D, O’Carroll AM, Lolait SJ. G protein-coupled receptors in the hypothalamic paraventricular and supraoptic nuclei--serpentine gateways to neuroendocrine homeostasis. Front Neuroendocrinol 2012; 33:45-66. [PMID: 21802439 PMCID: PMC3336209 DOI: 10.1016/j.yfrne.2011.07.002] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2011] [Revised: 06/24/2011] [Accepted: 07/06/2011] [Indexed: 12/31/2022]
Abstract
G protein-coupled receptors (GPCRs) are the largest family of transmembrane receptors in the mammalian genome. They are activated by a multitude of different ligands that elicit rapid intracellular responses to regulate cell function. Unsurprisingly, a large proportion of therapeutic agents target these receptors. The paraventricular nucleus (PVN) and supraoptic nucleus (SON) of the hypothalamus are important mediators in homeostatic control. Many modulators of PVN/SON activity, including neurotransmitters and hormones act via GPCRs--in fact over 100 non-chemosensory GPCRs have been detected in either the PVN or SON. This review provides a comprehensive summary of the expression of GPCRs within the PVN/SON, including data from recent transcriptomic studies that potentially expand the repertoire of GPCRs that may have functional roles in these hypothalamic nuclei. We also present some aspects of the regulation and known roles of GPCRs in PVN/SON, which are likely complemented by the activity of 'orphan' GPCRs.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | - Stephen J. Lolait
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, Dorothy Hodgkin Building, School of Clinical Sciences, University of Bristol, Whitson Street, Bristol BS1 3NY, UK
| |
Collapse
|
42
|
Conformational dynamics of helix 8 in the GPCR rhodopsin controls arrestin activation in the desensitization process. Proc Natl Acad Sci U S A 2011; 108:18690-5. [PMID: 22039220 DOI: 10.1073/pnas.1015461108] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Arrestins are regulatory molecules for G-protein coupled receptor function. In visual rhodopsin, selective binding of arrestin to the cytoplasmic side of light-activated, phosphorylated rhodopsin (P-Rh*) terminates signaling via the G-protein transducin. While the "phosphate-sensor" of arrestin for the recognition of receptor-attached phosphates is identified, the molecular mechanism of arrestin binding and the involvement of receptor conformations in this process are still largely hypothetic. Here we used fluorescence pump-probe and time-resolved fluorescence depolarization measurements to investigate the kinetics of arrestin conformational changes and the corresponding nanosecond dynamical changes at the receptor surface. We show that at least two sequential conformational changes of arrestin occur upon interaction with P-Rh*, thus providing a kinetic proof for the suggested multistep nature of arrestin binding. At the cytoplasmic surface of P-Rh*, the structural dynamics of the amphipathic helix 8 (H8), connecting transmembrane helix 7 and the phosphorylated C-terminal tail, depends on the arrestin interaction state. We find that a high mobility of H8 is required in the low-affinity (prebinding) but not in the high-affinity binding state. High-affinity arrestin binding is inhibited when a bulky, inflexible group is bound to H8, indicating close interaction. We further show that this close steric interaction of H8 with arrestin is mandatory for the transition from prebinding to high-affinity binding; i.e., for arrestin activation. This finding implies a regulatory role for H8 in activation of visual arrestin, which shows high selectivity to P-Rh* in contrast to the broad receptor specificity displayed by the two nonvisual arrestins.
Collapse
|
43
|
Feierler J, Wirth M, Welte B, Schüssler S, Jochum M, Faussner A. Helix 8 plays a crucial role in bradykinin B(2) receptor trafficking and signaling. J Biol Chem 2011; 286:43282-93. [PMID: 22016392 DOI: 10.1074/jbc.m111.256909] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Upon activation the human bradykinin B(2) receptor (B(2)R) acts as guanine nucleotide exchange factor for the G proteins G(q/11) and G(i). Thereafter, it gets phosphorylated by G protein-coupled receptor kinases (GRKs) and recruits β-arrestins, which block further G protein activation and promote B(2)R internalization via clathrin-coated pits. As for most G protein-coupled receptors of family A, an intracellular helix 8 after transmembrane domain 7 is also predicted for the B(2)R. We show here that disruption of helix 8 in the B(2)R by either C-terminal truncation or just by mutation of a central amino acid (Lys-315) to a helix-breaking proline resulted in strong reduction of surface expression. Interestingly, this malfunction could be overcome by the addition of the membrane-permeable B(2)R antagonist JSM10292, suggesting that helix 8 has a general role for conformational stabilization that can be accounted for by an appropriate antagonist. Intriguingly, an intact helix 8, but not the C terminus with its phosphorylation sites, was indispensable for receptor sequestration and for interaction of the B(2)R with GRK2/3 and β-arrestin2 as shown by co-immunoprecipitation. Recruitment of β-arrestin1, however, required the presence of the C terminus. Taken together, our results demonstrate that helix 8 of the B(2)R plays a crucial role not only in efficient trafficking to the plasma membrane or the activation of G proteins but also for the interaction of the B(2)R with GRK2/3 and β-arrestins. Additional data obtained with chimera of B(2)R with other G protein-coupled receptors of family A suggest that helix 8 might have similar functions in other GPCRs as well.
Collapse
Affiliation(s)
- Jens Feierler
- Abteilung für Klinische Chemie und Klinische Biochemie, Ludwig-Maximilians-Universität, Nussbaumstrasse 20, D-80336 München, Germany
| | | | | | | | | | | |
Collapse
|
44
|
Cook JL, Singh A, DeHaro D, Alam J, Re RN. Expression of a naturally occurring angiotensin AT(1) receptor cleavage fragment elicits caspase-activation and apoptosis. Am J Physiol Cell Physiol 2011; 301:C1175-85. [PMID: 21813711 DOI: 10.1152/ajpcell.00040.2011] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Several transmembrane receptors are documented to accumulate in nuclei, some as holoreceptors and others as cleaved receptor products. Our prior studies indicate that a population of the 7-transmembrane angiotensin type-1 receptor (AT(1)R) is cleaved in a ligand-augmented manner after which the cytoplasmic, carboxy-terminal cleavage fragment (CF) traffics to the nucleus. In the present report, we determine the precise cleavage site within the AT(1)R by mass spectrometry and Edman sequencing. Cleavage occurs between Leu(305) and Gly(306) at the junction of the seventh transmembrane domain and the intracellular cytoplasmic carboxy-terminal domain. To evaluate the function of the CF distinct from the holoreceptor, we generated a construct encoding the CF as an in-frame yellow fluorescent protein fusion. The CF accumulates in nuclei and induces apoptosis in CHO-K1 cells, rat aortic smooth muscle cells (RASMCs), MCF-7 human breast adenocarcinoma cells, and H9c2 rat cardiomyoblasts. All cell types show nuclear fragmentation and disintegration, as well as evidence for phosphotidylserine displacement in the plasma membrane and activated caspases. RASMCs specifically showed a 5.2-fold increase (P < 0.001) in CF-induced active caspases compared with control and a 7.2-fold increase (P < 0.001) in cleaved caspase-3 (Asp174). Poly(ADP-ribose)polymerase was upregulated 4.8-fold (P < 0.001) in CF expressing cardiomyoblasts and colocalized with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). CF expression also induces DNA laddering, the gold-standard for apoptosis in all cell types studied. CF-induced apoptosis, therefore, appears to be a general phenomenon as it is observed in multiple cell types including smooth muscle cells and cardiomyoblasts.
Collapse
Affiliation(s)
- Julia L Cook
- Laboratory of Molecular Genetics, Department of Research, Ochsner Clinic Foundation, New Orleans, LA 70121, USA.
| | | | | | | | | |
Collapse
|
45
|
Bettinelli I, Graziani D, Marconi C, Pedretti A, Vistoli G. The Approach of Conformational Chimeras to Model the Role of Proline-Containing Helices on GPCR Mobility: the Fertile Case of Cys-LTR1. ChemMedChem 2011; 6:1217-27. [DOI: 10.1002/cmdc.201100037] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2011] [Revised: 03/24/2011] [Indexed: 12/15/2022]
|
46
|
Wichard JD, ter Laak A, Krause G, Heinrich N, Kühne R, Kleinau G. Chemogenomic analysis of G-protein coupled receptors and their ligands deciphers locks and keys governing diverse aspects of signalling. PLoS One 2011; 6:e16811. [PMID: 21326864 PMCID: PMC3033908 DOI: 10.1371/journal.pone.0016811] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 01/12/2011] [Indexed: 11/28/2022] Open
Abstract
Understanding the molecular mechanism of signalling in the important super-family of G-protein-coupled receptors (GPCRs) is causally related to questions of how and where these receptors can be activated or inhibited. In this context, it is of great interest to unravel the common molecular features of GPCRs as well as those related to an active or inactive state or to subtype specific G-protein coupling. In our underlying chemogenomics study, we analyse for the first time the statistical link between the properties of G-protein-coupled receptors and GPCR ligands. The technique of mutual information (MI) is able to reveal statistical inter-dependence between variations in amino acid residues on the one hand and variations in ligand molecular descriptors on the other. Although this MI analysis uses novel information that differs from the results of known site-directed mutagenesis studies or published GPCR crystal structures, the method is capable of identifying the well-known common ligand binding region of GPCRs between the upper part of the seven transmembrane helices and the second extracellular loop. The analysis shows amino acid positions that are sensitive to either stimulating (agonistic) or inhibitory (antagonistic) ligand effects or both. It appears that amino acid positions for antagonistic and agonistic effects are both concentrated around the extracellular region, but selective agonistic effects are cumulated between transmembrane helices (TMHs) 2, 3, and ECL2, while selective residues for antagonistic effects are located at the top of helices 5 and 6. Above all, the MI analysis provides detailed indications about amino acids located in the transmembrane region of these receptors that determine G-protein signalling pathway preferences.
Collapse
Affiliation(s)
- Jörg D. Wichard
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
- Bayer-Schering Pharma, Berlin, Germany
| | | | - Gerd Krause
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
| | | | - Ronald Kühne
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
- * E-mail:
| | - Gunnar Kleinau
- Leibniz-Institut für Molekulare Pharmakologie, Berlin, Germany
- Institute of Experimental Pediatric Endocrinology, Charité Universitätsmedizin Berlin, Berlin, Germany
| |
Collapse
|
47
|
Donnellan PD, Kimbembe CC, Reid HM, Kinsella BT. Identification of a novel endoplasmic reticulum export motif within the eighth α-helical domain (α-H8) of the human prostacyclin receptor. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:1202-18. [PMID: 21223948 DOI: 10.1016/j.bbamem.2011.01.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2010] [Revised: 12/20/2010] [Accepted: 01/03/2011] [Indexed: 01/20/2023]
Abstract
The human prostacyclin receptor (hIP) undergoes agonist-dependent trafficking involving a direct interaction with Rab11a GTPase. The region of interaction was localised to a 14 residue Rab11a binding domain (RBD) within the proximal carboxyl-terminal (C)-tail domain of the hIP, consisting of Val(299)-Val(307) within the eighth helical domain (α-H8) adjacent to the palmitoylated residues at Cys(308)-Cys(311). However, the factors determining the anterograde transport of the newly synthesised hIP from the endoplasmic reticulum (ER) to the plasma membrane (PM) have not been identified. The aim of the current study was to identify the major ER export motif(s) within the hIP initially by investigating the role of Lys residues in its maturation and processing. Through site-directed and Ala-scanning mutational studies in combination with analyses of protein expression and maturation, functional analyses of ligand binding, agonist-induced intracellular signalling and confocal image analyses, it was determined that Lys(297), Arg(302) and Lys(304) located within α-H8 represent the critical determinants of a novel ER export motif of the hIP. Furthermore, while substitution of those critical residues significantly impaired maturation and processing of the hIP, replacement of the positively charged Lys with Arg residues, and vice versa, was functionally permissible. Hence, this study has identified a novel 8 residue ER export motif within the functionally important α-H8 of the hIP. This ER export motif, defined by "K/R(X)(4)K/R(X)K/R," has a strict requirement for positively charged, basic Lys/Arg residues at the 1st, 6th and 8th positions and appears to be evolutionarily conserved within IP sequences from mouse to man.
Collapse
MESH Headings
- Amino Acid Motifs
- Amino Acid Sequence
- Arginine/chemistry
- Arginine/genetics
- Arginine/metabolism
- Binding Sites
- Blotting, Western
- Calcium/metabolism
- Calnexin/metabolism
- Computational Biology
- Endoplasmic Reticulum/metabolism
- HEK293 Cells
- Humans
- Lysine/chemistry
- Lysine/genetics
- Lysine/metabolism
- Microscopy, Confocal
- Models, Molecular
- Molecular Sequence Data
- Mutagenesis, Site-Directed
- Mutation
- Protein Binding
- Protein Structure, Secondary
- Protein Structure, Tertiary
- Protein Transport
- Radioligand Assay
- Receptors, Epoprostenol/chemistry
- Receptors, Epoprostenol/genetics
- Receptors, Epoprostenol/metabolism
- Sequence Homology, Amino Acid
Collapse
Affiliation(s)
- Peter D Donnellan
- School of Biomeolecular and Biomedical Sciences, University College Dublin, Belfield, Dublin 4, Ireland
| | | | | | | |
Collapse
|
48
|
Lampert KP, Schmidt C, Fischer P, Volff JN, Hoffmann C, Muck J, Lohse MJ, Ryan MJ, Schartl M. Determination of onset of sexual maturation and mating behavior by melanocortin receptor 4 polymorphisms. Curr Biol 2010; 20:1729-34. [PMID: 20869245 DOI: 10.1016/j.cub.2010.08.029] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2010] [Revised: 07/16/2010] [Accepted: 08/13/2010] [Indexed: 11/30/2022]
Abstract
Polymorphisms in reproductive strategies are among the most extreme and complex in nature. A prominent example is male body size and the correlated reproductive strategies in some species of platyfish and swordtails of the genus Xiphophorus. This polymorphism is controlled by a single Mendelian locus (P) that determines the onset of sexual maturity of males. Because males cease growth after reaching puberty, this results in a marked size polymorphism. The different male size classes show pronounced behavioral differences (e.g., courtship versus sneak mating), and females prefer large over small males. We show that sequence polymorphisms of the melanocortin receptor 4 gene (mc4r) comprise both functional and non-signal-transducing versions and that variation in copy number of mc4r genes on the Y chromosome underlies the P locus polymorphism. Nonfunctional Y-linked mc4r copies in larger males act as dominant-negative mutations and delay the onset of puberty. Copy number variation, as a regulating mechanism, endows this system with extreme genetic flexibility that generates extreme variation in phenotype. Because Mc4r is critically involved in regulation of body weight and appetite, a novel link between the physiological system controlling energy balance and the regulation of reproduction becomes apparent.
Collapse
Affiliation(s)
- Kathrin P Lampert
- Physiological Chemistry I, Biocenter, University of Wuerzburg, Am Hubland, D-97074 Wuerzburg, Germany
| | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Nakamura M, Yasuda D, Hirota N, Shimizu T. Specific ligands as pharmacological chaperones: The transport of misfolded G-protein coupled receptors to the cell surface. IUBMB Life 2010; 62:453-9. [PMID: 20503438 DOI: 10.1002/iub.344] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
In the endoplasmic reticulum (ER), quality control mechanisms distinguish between correctly and incorrectly folded structures to ensure that aberrant proteins are not processed along the secretory pathway. Numerous studies have demonstrated the functional rescue of ER-retained, aberrant proteins by small membrane permeable molecules called pharmacological chaperones. Pharmacological chaperones can bind to misfolded proteins, including G-protein coupled receptors (GPCRs), and promote their correct folding and export from the ER. Recently, common structural features of GPCRs have been uncovered, including the eighth helical domain in the C-terminal tail and conserved residues in the transmembrane domains. However, little is known about the importance of these features in signaling and intracellular trafficking, because receptors deficient in these domains are likely retained in the ER due to misfolding. In this review, we summarize the current knowledge about the requirement of these consensus domains and amino acid residues for the passing through the quality control of the ER. Furthermore, we propose the utilization of membrane permeable ligands for the transport of their cognate, ER-retained GPCRs to the cell surface. The chaperone activity of these ligands allows us to perform functional analyses of the structure-deficient receptors after their trafficking to the cell surface.
Collapse
Affiliation(s)
- Motonao Nakamura
- Department of Biochemistry and Molecular Biology, Faculty of Medicine, The University of Tokyo, Hongo, Tokyo, Japan.
| | | | | | | |
Collapse
|
50
|
Vaudry H, Do Rego JC, Le Mevel JC, Chatenet D, Tostivint H, Fournier A, Tonon MC, Pelletier G, Conlon JM, Leprince J. Urotensin II, from fish to human. Ann N Y Acad Sci 2010; 1200:53-66. [PMID: 20633133 DOI: 10.1111/j.1749-6632.2010.05514.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The cyclic peptide urotensin II (UII) was originally isolated from the urophysis of teleost fish on the basis of its ability to contract intestinal smooth muscle. The UII peptide has subsequently been isolated from frog brain and, later on, the pre-proUII cDNA has been characterized in mammals, including humans. A UII paralog called urotensin II-related peptide (URP) has been identified in the rat brain. The UII and URP genes originate from the same ancestral gene as the somatostatin and cortistatin genes. In the central nervous system (CNS) of tetrapods, UII is expressed primarily in motoneurons of the brainstem and spinal cord. The biological actions of UII and URP are mediated through a G protein-coupled receptor, termed UT, that exhibits high sequence similarity with the somatostatin receptors. The UT gene is widely expressed in the CNS and in peripheral organs. Consistent with the broad distribution of UT, UII and URP exert a large array of behavioral effects and regulate endocrine, cardiovascular, renal, and immune functions.
Collapse
Affiliation(s)
- Hubert Vaudry
- Laboratory of Cellular Neuroendocrinology, INSERM U413, European Institute for Peptide Research (IFRMP 23), University of Rouen, Mont-Saint-Aignan, France.
| | | | | | | | | | | | | | | | | | | |
Collapse
|