Title: | Self-compatible B mutants in coprinus with altered pheromone-receptor specificities |
Author(s): | Olesnicky NS; Brown AJ; Honda Y; Dyos SL; Dowell SJ; Casselton LA; |
Address: | "Department of Plant Sciences, University of Oxford, Oxford OX1 3RB, United Kingdom" |
DOI: | 10.1093/genetics/156.3.1025 |
ISSN/ISBN: | 0016-6731 (Print) 0016-6731 (Linking) |
Abstract: | "A successful mating in the mushroom Coprinus cinereus brings together a compatible complement of pheromones and G-protein-coupled receptors encoded by multiallelic genes at the B mating-type locus. Rare B gene mutations lead to constitutive activation of B-regulated development without the need for mating. Here we characterize a mutation that arose in the B6 locus and show that it generates a mutant receptor with a single amino acid substitution (R96H) at the intracellular end of transmembrane domain III. Using a heterologous yeast assay and synthetic pheromones we show that the mutation does not make the receptor constitutively active but permits it to respond inappropriately to a normally incompatible pheromone encoded within the same B6 locus. Parallel experiments carried out in Coprinus showed that a F67W substitution in this same pheromone enabled it to activate the normally incompatible wild-type receptor. Together, our experiments show that a single amino acid replacement in either pheromone or receptor can deregulate the specificity of ligand-receptor recognition and confer a self-compatible B phenotype. In addition, we use the yeast assay to demonstrate that different receptors and pheromones found at a single B locus belong to discrete subfamilies within which receptor activation cannot normally occur" |
Keywords: | "Amino Acid Sequence Chemoreceptor Cells/*physiology Chromosome Mapping Chromosomes, Fungal/*genetics Coprinus/*genetics Crosses, Genetic Fungal Proteins/genetics/*physiology Genetic Complementation Test Mutagenesis, Site-Directed Pheromones/genetics Prote;" |
Notes: | "MedlineOlesnicky, N S Brown, A J Honda, Y Dyos, S L Dowell, S J Casselton, L A eng Research Support, Non-U.S. Gov't 2000/11/07 Genetics. 2000 Nov; 156(3):1025-33. doi: 10.1093/genetics/156.3.1025" |