Selective modulation of wild type receptor functions by mutants of G-protein-coupled receptors.
Members of the G-protein-coupled receptor (GPCR) family are involved in most aspects of higher eukaryote biology, and mutations in their coding sequence have been linked to several diseases. In the present study, we report that mutant GPCR can affect the functional properties of the co-expressed wild type (WT) receptor. Mutants of the human platelet-activating factor receptor that fail to show any detectable ligand binding (N285I and K298stop) or coupling to a G-protein (D63N, D289A, and Y293A) were co-expressed with the WT receptor in Chinese hamster ovary and COS-7 cells. In this context, N285I and K298stop mutant receptors inhibited 3H-WEB2086 binding and surface expression. Co-transfection with D63N resulted in a constitutively active receptor phenotype. Platelet-activating factor-induced inositol phosphate production in cells transfected with a 1:1 ratio of WT:D63N was higher than with the WT cDNA alone but was abolished with a 1:3 ratio. We confirmed that these findings could be extended to other GPCRs by showing that co-expression of the WT C-C chemokine receptor 2b with a carboxyl-terminal deletion mutant (K311stop), resulted in a decreased affinity and responsiveness to MCP-1. A better understanding of this phenomenon could lead to important tools for the prevention or treatment of certain diseases.
Le Gouill
C
C
Immunology Division, Department of Pediatrics, Faculty of Medicine, University of Sherbrooke, Sherbrooke, Quebec J1H 5N4, Canada. sternsdo@hpi@uni-hamburg.de
Parent
J L
JL
Caron
C A
CA
Gaudreau
R
R
Volkov
L
L
Rola-Pleszczynski
M
M
Stanková
J
J
D000818:Animals; D001381:Azepines / Q000494:pharmacology; D001483:Base Sequence; D016466:CHO Cells; D019556:COS Cells; D018932:Chemokine CCL2 / Q000378:metabolism; D006224:Cricetinae; D017931:DNA Primers; D019204:GTP-Binding Proteins / Q000378:metabolism*; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D016296:Mutagenesis; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D010980:Platelet Membrane Glycoproteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D054390:Receptors, CCR2; D011956:Receptors, Cell Surface; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine / Q000235:genetics; D043562:Receptors, G-Protein-Coupled; D014162:Transfection; D014230:Triazoles / Q000494:pharmacology
D001381:Azepines; C515334:CCR2 protein, human; D018932:Chemokine CCL2; D017931:DNA Primers; D007295:Inositol Phosphates; D010975:Platelet Aggregation Inhibitors; D010980:Platelet Membrane Glycoproteins; D054390:Receptors, CCR2; D011956:Receptors, Cell Surface; D019707:Receptors, Chemokine; D018121:Receptors, Cytokine; D043562:Receptors, G-Protein-Coupled; D014230:Triazoles; C039351:platelet activating factor receptor; C052518:WEB 2086; D019204:GTP-Binding Proteins