|
|
|
|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Institute of Pharmacology, University of Heidelberg, Heidelberg, Germany (S.T., J.K., S.O.); and Forschungsinstitut für Molekulare Pharmakologie, Berlin, Germany (J.L., G.K.)
The G-protein-coupled receptor GPR109A (HM74A/PUMA-G) has recently been shown to function as a receptor for nicotinic acid (niacin) and to mediate its antilipolytic effects. Nicotinic acid is able to strongly raise plasma levels of high-density lipoprotein cholesterol, a property that distinguishes nicotinic acid from other lipid-lowering drugs. To investigate the structural determinants of GPR109A ligand binding, we performed site-directed mutagenesis of putative ligand binding residues combined with generation of chimeric receptors consisting of GPR109A and its close relative GPR109B, which does not bind nicotinic acid. We could identify Asn86/Trp91 [transmembrane helix (TMH) 2/extracellular loop (ECL) 1], Arg111 (TMH3), Ser178 (ECL2), Phe276 (TMH7), and Tyr284 (TMH7) as amino acid residues critical for binding of nicotinic acid. Together with data from molecular modeling studies, our data suggest that the ligand binding pocket for nicotinic acid of GPR109A is distinct from that of most other group A receptors. Although Arg111 at TMH3 serves as the basic anchor point for the carboxylate ligands, the ring system of nicotinic acid is embedded between Trp91 at the junction TMH2/ECL1 and Phe276/Tyr284 at TMH7. The heterocyclic ring is also bound to Ser178 at ECL2 via an H-bond. These data will facilitate the design of new antidyslipidemic drugs acting via GPR109A.
Address correspondence to: Stefan Offermanns, Institute of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany. E-mail: stefan.offermanns{at}urz.uni-heidelberg.de
This article has been cited by other articles:
![]() |
C. Liu, J. Wu, J. Zhu, C. Kuei, J. Yu, J. Shelton, S. W. Sutton, X. Li, S. J. Yun, T. Mirzadegan, et al. Lactate Inhibits Lipolysis in Fat Cells through Activation of an Orphan G-protein-coupled Receptor, GPR81 J. Biol. Chem., January 30, 2009; 284(5): 2811 - 2822. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Neumann, G. Kleinau, S. Costanzi, S. Moore, J.-k. Jiang, B. M. Raaka, C. J. Thomas, G. Krause, and M. C. Gershengorn A Low-Molecular-Weight Antagonist for the Human Thyrotropin Receptor with Therapeutic Potential for Hyperthyroidism Endocrinology, December 1, 2008; 149(12): 5945 - 5950. [Abstract] [Full Text] [PDF] |
||||
![]() |
L. A. Stoddart, N. J. Smith, L. Jenkins, A. J. Brown, and G. Milligan Conserved Polar Residues in Transmembrane Domains V, VI, and VII of Free Fatty Acid Receptor 2 and Free Fatty Acid Receptor 3 Are Required for the Binding and Function of Short Chain Fatty Acids J. Biol. Chem., November 21, 2008; 283(47): 32913 - 32924. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. D. Lim, A. Jongejan, R. A. Bakker, E. Haaksma, I. J. P. de Esch, and R. Leurs Phenylalanine 169 in the Second Extracellular Loop of the Human Histamine H4 Receptor Is Responsible for the Difference in Agonist Binding between Human and Mouse H4 Receptors J. Pharmacol. Exp. Ther., October 1, 2008; 327(1): 88 - 96. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. S. Torhan, B. Cheewatrakoolpong, L. Kwee, and S. Greenfeder Cloning and characterization of the hamster and guinea pig nicotinic acid receptors J. Lipid Res., September 1, 2007; 48(9): 2065 - 2071. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Basu, V. R. Jala, S. Mathis, S. T. Rajagopal, A. Del Prete, P. Maturu, J. O. Trent, and B. Haribabu Critical Role for Polar Residues in Coupling Leukotriene B4 Binding to Signal Transduction in BLT1 J. Biol. Chem., March 30, 2007; 282(13): 10005 - 10017. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Krietsch, M. S. Fernandes, J. Kero, R. Losel, M. Heyens, E. W.-F. Lam, I. Huhtaniemi, J. J. Brosens, and B. Gellersen Human Homologs of the Putative G Protein-Coupled Membrane Progestin Receptors (mPR{alpha}, {beta}, and {gamma}) Localize to the Endoplasmic Reticulum and Are Not Activated by Progesterone Mol. Endocrinol., December 1, 2006; 20(12): 3146 - 3164. [Abstract] [Full Text] [PDF] |
||||
![]() |
H. Jaschke, S. Neumann, S. Moore, C. J. Thomas, A.-O. Colson, S. Costanzi, G. Kleinau, J.-K. Jiang, R. Paschke, B. M. Raaka, et al. A Low Molecular Weight Agonist Signals by Binding to the Transmembrane Domain of Thyroid-stimulating Hormone Receptor (TSHR) and Luteinizing Hormone/Chorionic Gonadotropin Receptor (LHCGR) J. Biol. Chem., April 14, 2006; 281(15): 9841 - 9844. [Abstract] [Full Text] [PDF] |
||||