Characterization of dominant lethal mutations in the yeast plasma membrane H+-ATPase gene.
Site-directed mutants of yeast ATPase were studied after introduction of mutant alleles into a yeast strain where these alleles were constitutively expressed and the expression of the wild-type chromosomal ATPase gene was turned off. One objection to this constitutive expression system was made apparent recently, as dominant lethal mutations are lost by gene conversion with the wild-type allele during the process. Here, the phenotypes of the mutant alleles, which were studied in a constitutive expression system, are re-evaluated under conditions in which these site-directed mutants are conditionally expressed. We show that 12 of 25 site-directed mutations previously described are actually dominant lethal alleles. In addition, we show that dominant mutant proteins interfere with transport of wild-type ATPase to the plasma membrane.
Portillo
F
F
Departamento de Bioquímica de la Facultad de Medicina de la Universidad Autónoma de Madrid, Spain. FPortillo@biomed.iib.uam.es
D002462:Cell Membrane / Q000201:enzymology; D015825:Chromosomes, Fungal; D005799:Genes, Dominant; D005804:Genes, Lethal; D005808:Genes, Recessive; D008961:Models, Structural; D016297:Mutagenesis, Site-Directed; D010957:Plasmids; D011487:Protein Conformation; D006180:Proton-Translocating ATPases / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development
D011994:Recombinant Proteins; D006180:Proton-Translocating ATPases