This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Copyright Permission Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kitanovic, S. Articles by Sealfon, S. C. Search for Related Content PubMed PubMed Citation Articles by Kitanovic, S. Articles by Sealfon, S. C.

Insertional Mutagenesis of the Arginine Cage Domain of the Gonadotropin-Releasing Hormone Receptor

Fishberg Research Center for Neurobiology (S.K., T.Y., S.C.S.) and Department of Neurology (C.A.F., B.J.E., S.C.S.) Mount Sinai School of Medicine New York, New York 10029

The pattern of side-chain conservation at the cytoplasmic side of the third transmembrane domain of rhodopsin family G protein-coupled receptors, Asp/Glu-Arg-Tyr/X-X-X-Ile/Val, defines a structural "arginine cage" domain. Previous computational and mutagenesis studies of the GnRH receptor indicated an important contribution of local interactions to the function of this domain. We have investigated the functional importance of the intrahelical position and orientation of the arginine cage using insertional mutagenesis. Introduction of a single Ala proximal to the conserved Asp-Arg of this domain caused loss of detectable ligand binding. Inserting a second Ala, however, restored high-affinity agonist binding. Further insertion of three or four Ala residues at this site generated receptors that bound agonist with an affinity 3- to 10-fold higher than that of the wild-type receptor. Loss of detectable coupling to inositol phosphate turnover in all these mutant receptors confirms that the structure required in this region for efficient signaling is highly constrained. In contrast, the recovery of agonist binding with the progressive insertion of two to four Ala residues indicates that specific orientations of this segment can stabilize high-affinity receptor conformations that are uncoupled from signal transduction.

This article has been cited by other articles:

				M R Silver and S A Sower Functional characterization and kinetic studies of an ancestral lamprey GnRH-III selective type II GnRH receptor from the sea lamprey, Petromyzon marinus. J. Mol. Endocrinol., June 1, 2006; 36(3): 601 - 610. [Abstract] [Full Text] [PDF]

				C. Prioleau, I. Visiers, B. J. Ebersole, H. Weinstein, and S. C. Sealfon Conserved Helix 7 Tyrosine Acts as a Multistate Conformational Switch in the 5HT2C Receptor. IDENTIFICATION OF A NOVEL "LOCKED-ON" PHENOTYPE AND DOUBLE REVERTANT MUTATIONS J. Biol. Chem., September 20, 2002; 277(39): 36577 - 36584. [Abstract] [Full Text] [PDF]