Modulation of GPCR Conformationsby Ligands, G-Proteins, and Arrestins

Conference paper
Part of the Ernst Schering Foundation Symposium Proceedings book series (SCHERING FOUND, volume 2006/2)


G-protein-coupled receptors (GPCRs) have traditionally been thought to adopt two conformations: the inactive unliganded conformation and the active ligand-bound conformation. Interactions with G-proteins in cells and membranes are known to modulate the affinity of the receptor for ligand and therefore the conformation of the receptor. Such observations led to the proposal of the ternary complex model. However, subsequent studies of constitutively active GPCRs led to the development of an extended version of this model to account for active conformations of the receptor in the absence of agonist. A significant difficulty with many of the studies, upon which this latter model was based, is the lack of knowledge of receptor and G-protein concentrations due to the two-dimensional nature of the membranes used to perform the measurements. Over the past decade, we have studied the interaction of GPCRs, G-proteins, arrestins, and ligands in solubilized systems, where the concentration of each component can be defined. Here we summarize results of these studies as they pertain to the regulation of GPCR conformations and affinities for interacting species.


Ternary Complex Partial Agonist Ligand Affinity Receptor Phosphorylation High Ligand Affinity 



Work in the authors' laboratories was supported by grants AI36357 and AI43932 (ERP) and EB00264 (LAS) from the National Institutes of Health, U.S. Public Health Service. We also appreciate the contribution of Dr. Anna Waller to computations efforts.


  1. Bennett TA, Foutz TD, Gurevich VV, Sklar LA, Prossnitz ER (2001a) Partial phosphorylation of the N-formyl peptide receptor inhibits G protein association independent of arrestin binding. J Biol Chem 276:49195–49203CrossRefPubMedGoogle Scholar
  2. Bennett TA, Key TA, Gurevich VV, Neubig R, Prossnitz ER, Sklar LA (2001b) Real-time analysis of G protein-coupled receptor reconstitution in a solubilized system. J Biol Chem 276:22453–22460CrossRefPubMedGoogle Scholar
  3. Fay SP, Posner RG, Swann WN, Sklar LA (1991) Real-time analysis of the assembly of ligand, receptor, and G protein by quantitative fluorescence flow cytometry. Biochemistry 30:5066–5075CrossRefPubMedGoogle Scholar
  4. Hill SJ (2006) G-protein-coupled receptors: past, present and future. Br J Pharmacol 147(Suppl 1):S27–37PubMedGoogle Scholar
  5. Key TA, Bennett TA, Foutz TD, Gurevich VV, Sklar LA, Prossnitz ER (2001) Regulation of formyl peptide receptor agonist affinity by reconstitution with arrestins and heterotrimeric g proteins. J Biol Chem 276:49204–49212CrossRefPubMedGoogle Scholar
  6. Key TA, Foutz TD, Gurevich VV, Sklar LA, Prossnitz ER (2003) N-formyl peptide receptor phosphorylation domains differentially regulate arrestin and agonist affinity. J Biol Chem 278:4041–4047CrossRefPubMedGoogle Scholar
  7. Key TA, Vines CM, Wagener BM, Gurevich VV, Sklar LA, Prossnitz ER (2005) Inhibition of chemoattractant N-formyl peptide receptor trafficking by active arrestins. Traffic 6:87–99CrossRefPubMedGoogle Scholar
  8. Le Y, Murphy PM, Wang JM (2002) Formyl-peptide receptors revisited. Trends Immunol 23:541–548CrossRefPubMedGoogle Scholar
  9. Luttrell LM (2005) Composition and function of G protein-coupled receptor signalsomes controlling mitogen-activated protein kinase activity. J Mol Neurosci 26:253–264CrossRefPubMedGoogle Scholar
  10. Maestes DC, Potter RM, Prossnitz ER (1999) Differential phosphorylation paradigms dictate desensitization and internalization of the N-formyl peptide receptor. J Biol Chem 274:29791–29795CrossRefPubMedGoogle Scholar
  11. Maudsley S, Martin B, Luttrell LM (2005) The origins of diversity and specificity in G protein-coupled receptor signaling. J Pharmacol Exp Ther 314:485–494CrossRefPubMedGoogle Scholar
  12. Niedel J, Kahane I, Lachman L, Cuatrecasas P (1980) A subpopulation of cultured human promyelocytic leukemia cells (HL-60) displays the formyl peptide chemotactic receptor. Proc Natl Acad Sci USA 77:1000–1004CrossRefPubMedGoogle Scholar
  13. Prossnitz ER (2004) Novel roles for arrestins in the post-endocytic trafficking of G protein-coupled receptors. Life Sci 75:893–899CrossRefPubMedGoogle Scholar
  14. Prossnitz ER, Ye RD (1997) The N-formyl peptide receptor: a model for the study of chemoattractant receptor structure and function. Pharmacol Ther 74:73–102CrossRefPubMedGoogle Scholar
  15. Prossnitz ER, Gilbert TL, Chiang S, Campbell JJ, Qin S, Newman W, Sklar LA, Ye RD (1999) Multiple activation steps of the N-formyl peptide receptor. Biochemistry 38:2240–2247CrossRefPubMedGoogle Scholar
  16. Schmitt M, Painter RG, Jesaitis AJ, Preissner K, Sklar LA, Cochrane CG (1983) Photoaffinity labeling of the N-formyl peptide receptor binding site of intact human polymorphonuclear leukocytes. A label suitable for following the fate of the receptor-ligand complex. J Biol Chem 258:649–654PubMedGoogle Scholar
  17. Simons PC, Shi M, Foutz T, Cimino DF, Lewis J, Buranda T, Lim WK, Neubig RR, McIntire WE, Garrison J, Prossnitz E, Sklar LA (2003) Ligand-receptor-G-protein molecular assemblies on beads for mechanistic studies and screening by flow cytometry. Mol Pharmacol 64:1227–1238CrossRefPubMedGoogle Scholar
  18. Simons PC, Biggs SM, Waller A, Foutz T, Cimino DF, Guo Q, Neubig RR, Tang WJ, Prossnitz ER, Sklar LA (2004) Real-time analysis of ternary complex on particles: direct evidence for partial agonism at the agonist-receptor-G protein complex assembly step of signal transduction. J Biol Chem 279:13514–13521CrossRefPubMedGoogle Scholar
  19. Sklar LA, Oades ZG, Jesaitis AJ, Painter RG, Cochrane CG (1981) Fluoresceinated chemotactic peptide and high-affinity antifluorescein antibody as a probe of the temporal characteristics of neutrophil stimulation. Proc Natl Acad Sci USA 78:7540–7544CrossRefPubMedGoogle Scholar
  20. Sklar LA, Finney DA, Oades ZG, Jesaitis AJ, Painter RG, Cochrane CG (1984) The dynamics of ligand-receptor interactions. Real-time analyses of association, dissociation, and internalization of an N-formyl peptide and its receptors on the human neutrophil. J Biol Chem 259:5661–5669PubMedGoogle Scholar
  21. Sklar LA, Hyslop PA, Oades ZG, Omann GM, Jesaitis AJ, Painter RG, Cochrane CG (1985) Signal transduction and ligand-receptor dynamics in the human neutrophil. Transient responses and occupancy–response relations at the formyl peptide receptor. J Biol Chem 260:11461–11467PubMedGoogle Scholar
  22. Sklar LA, Bokoch GM, Button D, Smolen JE (1987) Regulation of ligand-receptor dynamics by guanine nucleotides. Real-time analysis of interconverting states for the neutrophil formyl peptide receptor. J Biol Chem 262:135–139PubMedGoogle Scholar
  23. Sklar LA, Mueller H, Omann G, Oades Z (1989) Three states for the formyl peptide receptor on intact cells. J Biol Chem 264:8483–8486PubMedGoogle Scholar
  24. Sklar LA, Vilven J, Lynam E, Neldon D, Bennett TA, Prossnitz E (2000) Solubilization and display of G protein-coupled receptors on beads for real-time fluorescence and flow cytometric analysis. Biotechniques 28:976–985PubMedGoogle Scholar
  25. Sklar LA, Edwards BS, Graves SW, Nolan JP, Prossnitz ER (2002) Flow cytometric analysis of ligand-receptor interactions and molecular assemblies. Annu Rev Biophys Biomol Struct 31:97–119CrossRefPubMedGoogle Scholar
  26. Vauquelin G, Van Liefde I (2005) G protein-coupled receptors: A count of 1001 conformations. Fundam Clin Pharmacol 19:45–56CrossRefPubMedGoogle Scholar
  27. Vilven JC, Domalewski M, Prossnitz ER, Ye RD, Muthukumaraswamy N, Harris RB, Freer RJ, Sklar LA (1998) Strategies for positioning fluorescent probes and crosslinkers on formyl peptide ligands. J Recept Signal Transduct Res 18:187–221CrossRefPubMedGoogle Scholar
  28. Wise A, Gearing K, Rees S (2002) Target validation of G-protein coupled receptors. Drug Discov Today 7:235–246CrossRefPubMedGoogle Scholar

Copyright information

© Springer-Verlag 2007

Authors and Affiliations

  1. 1.Department of Cell Biology and PhysiologyCancer Research and Treatment Center, University of New Mexico Health Sciences CenterAlbuquerque NMUSA

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