RT Journal Article
SR Electronic
T1 Identification of Leu276 of the S1P<sub>1</sub> Receptor and Phe263 of the S1P<sub>3</sub> Receptor in Interaction with Receptor Specific Agonists by Molecular Modeling, Site-Directed Mutagenesis, and Affinity Studies
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 724
OP 735
DO 10.1124/mol.106.029223
VO 71
IS 3
A1 Qiaolin Deng
A1 Joseph A. Clemas
A1 Gary Chrebet
A1 Paul Fischer
A1 Jeffrey J. Hale
A1 Zhen Li
A1 Sander G. Mills
A1 James Bergstrom
A1 Suzanne Mandala
A1 Ralph Mosley
A1 Stephen A. Parent
YR 2007
UL http://molpharm.aspetjournals.org/content/71/3/724.abstract
AB Sphingosine-1-phosphate (S1P) receptor agonists are novel immunosuppressive agents. The selectivity of S1P1 against S1P3 is strongly correlated with lymphocyte sequestration and minimum acute toxicity and bradycardia. This study describes molecular modeling, site-directed mutagenesis, and affinity studies exploring the molecular basis for selectivity between S1P1 and S1P3 receptors. Computational models of human S1P1 and S1P3 receptors bound with two nonselective agonists or two S1P1-selective agonists were developed based on the X-ray crystal structure of bovine rhodopsin. The models predict that S1P1 Leu276 and S1P3 Phe263 contribute to the S1P1/S1P3 selectivity of the two S1P1-selective agonists. These residues were subjected to site-directed mutagenesis. The wild-type and mutant S1P receptors were expressed in Chinese hamster ovary cells and examined for their abilities to bind to and be activated by agonists in vitro. The results indicate that the mutations have minimal effects on the activities of the two nonselective agonists, although they have dramatic effects on the S1P1-selective agonists. These studies provide a fundamental understanding of how these two receptor-selective agonists bind to the S1P1 and S1P3 receptors, which should aid development of more selective S1P1 receptor agonists with immunosuppressive properties and improved safety profiles. The American Society for Pharmacology and Experimental Therapeutics