Effects of Asn87 and Asp318 mutations on ligand binding and signal transduction in the rat GnRH receptor.
The gonadotrophin-releasing hormone (GnRH) receptor is unlike other G-protein coupled receptors in that the highly conserved amino acids, Asp in the second transmembrane region and Asn in the seventh, are interchanged. Site-directed mutagenesis studies mutated these residues back to their normally conserved positions. Two single mutants Asn87Asp & Asp318Asn and one double mutant Asn87Asp Asp318Asn were transiently expressed in COS-1 cells and their effect on binding to GnRH and inositol phosphate production measured. The single mutant Asp318Asn had no effect on ligand binding but abolished GnRH-dependent inositol phosphate production, whereas mutations Asn87Asp and Asn87Asp Asp318Asn show a complete loss of GnRH binding and subsequent inactivation of its second messenger system.
Cook
J V
JV
MRC Reproductive Biology Unit, Centre for Reproductive Biology, Edinburgh, United Kingdom.
Faccenda
E
E
Anderson
L
L
Couper
G G
GG
Eidne
K A
KA
Taylor
P L
PL
D000595:Amino Acid Sequence; D000596:Amino Acids / Q000737:chemistry*; D000818:Animals; D002460:Cell Line; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D007295:Inositol Phosphates / Q000096:biosynthesis; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011485:Protein Binding; D051381:Rats; D011966:Receptors, LHRH / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D015398:Signal Transduction
D000596:Amino Acids; D007295:Inositol Phosphates; D011966:Receptors, LHRH; D007987:Gonadotropin-Releasing Hormone