RT Journal Article
SR Electronic
T1 A reciprocal mutation supports helix 2 and helix 7 proximity in the gonadotropin-releasing hormone receptor.
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP 165
OP 170
VO 45
IS 2
A1 W Zhou
A1 C Flanagan
A1 J A Ballesteros
A1 K Konvicka
A1 J S Davidson
A1 H Weinstein
A1 R P Millar
A1 S C Sealfon
YR 1994
UL http://molpharm.aspetjournals.org/content/45/2/165.abstract
AB Activation of the pituitary gonadotropin-releasing hormone receptor, a member of the seven-transmembrane G protein-coupled receptor (GPCR) family, triggers a cascade of events leading to gonadotropin release and stimulation of the reproductive system. An unusual feature of this receptor, observed in mice, rats, and humans, is the presence of Asn87 in the second putative transmembrane helix at the location of a highly conserved aspartate in the GPCR family and of Asp318 in the putative seventh transmembrane helix where nearly all other GPCRs have asparagine. The possibility that these residues interact was suggested by this reciprocal pattern and by a three-dimensional model of the gonadotropin-releasing hormone receptor and was investigated by site-directed mutagenesis. Replacing Asn87 in the second transmembrane domain by aspartate eliminated detectable ligand binding. A second mutation, generating the double-mutant receptor Asp87Asn318, recreated the arrangement found in other GPCRs and re-established high affinity agonist and antagonist binding. The restoration of binding by a reciprocal mutation indicates that these two specific residues in helices 2 and 7 are adjacent in space and provides an empirical basis to refine the model of the transmembrane helix bundle of the receptor.