ISSN:
1432-0983
Schlagwort(e):
Key words G protein-coupled receptor
;
Peptide
;
α-factor
;
Ligand selectivity
;
Pheromone
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Biologie
Notizen:
Abstract The specificity of mating-pheromone systems helps prevent mating between different species of yeast. The mechanism of specificity of G protein-coupled receptors in other organisms may be similar. To determine the structural basis of species discrimination between α-factor variants, small extracellular segments of the Saccharomyces cerevisiaeα-factor receptor were substituted with residues from the Saccharomyces kluyveriα-factor receptor. Three substitutions altered specificity towards S. cerevisiae and S. kluyveriα-factor pheromone peptides. A substitution at residues 47–49 affected specificity for pheromone binding but not for pheromone activation of response. Substitution of residues 267–269 affected pheromone specificity for activation of cellular responses, but not for pheromone binding (under the assay conditions used). Substitution of residues 104–123 modestly affected both types of specificity. These results suggest two distinct types of receptor/ligand specificity (perhaps corresponding to ligand binding to G protein-coupled or uncoupled conformational states of the receptor) that evolved independently as S. cerevisiae and S. kluyveri diverged as species.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/s002940050200
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