DRA symposium on Receptor structure and function
Wednesday May 7 2008, 13:00-17:30 in Auditorium 3
The Faculty of Pharmaceutical Sciences, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen Ø
Program
| 13:00 - 13:05 | Welcome Jette Sandholm Kastrup, University of Copenhagen |
| 13:05 - 13:50 | Structure of the beta adrenergic receptors: Progress in obtaining recombinant G protein coupled receptor structures Gebhard F. X. Schertler, MRC Laboratory of Molecular Biology, Cambridge, UK |
| 13:50 - 14:05 | Discussions |
| 14:05 - 14:30 | Coffee |
| 14:30 - 15:15 | New insights from heterodimers of orphan G-protein-coupled receptors Ralf Jockers, Institut Cochin, INSERM U567, Université Paris Descartes, France |
| 15:15 - 15:30 | Discussions |
| 15:30 - 16:15 | Dissection of the growth factor signaling pathway via quantitative phosphoproteomics Irina Kratchmarova, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark |
| 16:15 - 16:30 | Discussions |
| 16:30 - 16:35 | Concluding remarks |
| 16:35 - 17:30 | Beer and snacks! |
Organized on behalf of the Drug Research Academy, PHARMA by Michael Gajhede, Hans Bräuner-Osborne, Jan Egebjerg and Jette Sandholm Kastrup, Department of Medicinal Chemistry at The Faculty of Pharmaceutical Sciences, University of Copenhagen, e-mail: jsk(at)farma.ku.dk
The participation is free of charge and is open for attendance by all interested parties. No prior registration is required.
Abstracts:
Structure of the Beta Adrenergic Receptors: Progress in obtaining recombinant G protein Coupled Receptor Structures
Gebhard F X Schertler
MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
G protein coupled receptors (GPCRs) are remarkably versatile signalling molecules. There has been significant progress in understanding the pharmacology, cell biology and physiology of this large family of membrane proteins over past two decades. Yet we still know very little about the structural basis of GPCR-mediated signal transduction. I will discuss recent progress in efforts to obtain high-resolution crystal structures of recombinant stabilised rhodopsin and beta adrenergic receptors. Stabilisation of the expressed receptors is essential for success in crystallisation and data collection. The development of micro crystallography techniques has played an important role in this effort, allowing the collection of diffraction data from crystals that are too small and heterogeneous to analyse using conventional synchrotron radiation sources. Mammalian membrane proteins are invariably less stable than bacterial membrane proteins after detergent solubilisation and purification, which makes them far more difficult to crystallise. We have developed a generic methodology based upon alanine scanning mutagenesis and a selection strategy to improve the thermo stability of any membrane protein. This was used to stabilise the 1 adrenergic receptor. The thermo stabilised mutant bAR-m23 contained 6 mutations and was more stable than the wild type protein by 21˚C. This allowed the purification and crystallisation of the protein in small detergents, which normally causes the receptor to denature and aggregate. The 2.7Å structure clearly shows the ligand in the receptor binding pocket and will be compared with the recently determined structures of the beta adrenergic receptor and the rhodopsin structure. Similarities and differences between rhodopsin and catecholamine receptors will be highlighted. The implications of the new GPCR structure templates for modelling other GPCRs will be discussed. Further progress in this area will provide new mechanistic insights into GPCR signal transduction and enhance rational structure-based drug discovery for this large family of pharmacological targets.
Maria J. Serrano-Vega, Francesca Magnani, Yoko Shibata & Christopher G. Tate* (2008) Conformational thermostabilisation of the -adrenergic receptor in a detergent-resistant form. Proc Natl Acad Sci USA 105, 877-882
Tony Warne, Maria J. Serrano-Vega, Jillian G. Baker#, Rouslan Moukhametzianov, Patricia C. Edwards, Richard Henderson, Andrew G.W. Leslie, Christopher G. Tate* & Gebhard F.X. Schertler* (2008) Structure of b1 adrenergic G protein-coupled receptor. Manuscript in preparation
MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
# School of Medicine, Institute of Cell Signalling, Nottingham NG7 2UH, UK
New insights from heterodimers of orphan G protein-coupled receptors
Ralf Jockers, Institut Cochin, INSERM U567, Université Paris Descartes, France
G protein-coupled receptors (GPCRs), also characterized as 7 transmembrane proteins (7TM), constitute the largest family of membrane receptors in humans with approximately 800 members, which are equally divided into odorant and non-odorant receptors. More than 100 of the non-odorant GPCRs are still orphans (without assigned ligand). Part of these orphans are likely to be deorphenized in the future by matching them with their natural ligand. Recent evidence however suggests that some of these 7TM proteins might be true orphans for which no endogenous ligand exists. The evolutionary conservation of these orphans indicates that other, ligand-independent functions exist for these proteins. Regulation of the function of non-orphan GPCRs through heterodimerization with orphans might be one of these ligand-independent functions. Several examples reported in the literature support this new role of orphan 7TM proteins in heterodimers.
Dissection of the growth factor signaling pathway via quantitative phosphoproteomics
Irina Kratchmarova, Department of Biochemistry and Molecular Biology, University of Southern Denmark, Odense, Denmark
The binding of growth factors to their corresponding receptors on the cell surface initiates signal transduction cascades that induce a defined cellular response. The transmission of signal from the plasma membrane to the nucleus is accomplished via complex network of receptors, kinases, adaptor and scaffold proteins. The development of mass spectrometry based quantitative approaches greatly facilitates investigation of the signal depended interactions and creation of interaction networks. Here we demonstrate how SILAC methodology can be utilized to compare entire signaling pathways initiated by different signals. Examples will include the EGF and PDGF signaling in human mesenchymal stem cells as well as the insulin and IGF-1 dependent signal transduction cascades in adipocytes.
