A Saccharomyces cerevisiae genome-wide mutant screen for altered sensitivity to K1 killer toxin.
Using the set of Saccharomyces cerevisiae mutants individually deleted for 5718 yeast genes, we screened for altered sensitivity to the antifungal protein, K1 killer toxin, that binds to a cell wall beta-glucan receptor and subsequently forms lethal pores in the plasma membrane. Mutations in 268 genes, including 42 in genes of unknown function, had a phenotype, often mild, with 186 showing resistance and 82 hypersensitivity compared to wild type. Only 15 of these genes were previously known to cause a toxin phenotype when mutated. Mutants for 144 genes were analyzed for alkali-soluble beta-glucan levels; 63 showed alterations. Further, mutants for 118 genes with altered toxin sensitivity were screened for SDS, hygromycin B, and calcofluor white sensitivity as indicators of cell surface defects; 88 showed some additional defect. There is a markedly nonrandom functional distribution of the mutants. Many genes affect specific areas of cellular activity, including cell wall glucan and mannoprotein synthesis, secretory pathway trafficking, lipid and sterol biosynthesis, and cell surface signal transduction, and offer new insights into these processes and their integration.
Pagé
Nicolas
N
Biology Department, McGill University, Montreal, Quebec H3A 1B1, Canada.
Gérard-Vincent
Manon
M
Ménard
Patrice
P
Beaulieu
Maude
M
Azuma
Masayuki
M
Dijkgraaf
Gerrit J P
GJ
Li
Huijuan
H
Marcoux
José
J
Nguyen
Thuy
T
Dowse
Tim
T
Sdicu
Anne-Marie
AM
Bussey
Howard
H
D002473:Cell Wall / Q000737:chemistry; D005656:Fungal Proteins / Q000633:toxicity*; D015966:Gene Expression Regulation, Fungal; D016681:Genome, Fungal; D005936:Glucans / Q000235:genetics / Q000378:metabolism; D055646:Killer Factors, Yeast; D016296:Mutagenesis; D009183:Mycotoxins / Q000633:toxicity*; D016366:Open Reading Frames; D010641:Phenotype; D012270:Ribosomes / Q000235:genetics; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000235:genetics*; D017384:Sequence Deletion; D047071:beta-Glucans
D005656:Fungal Proteins; D005936:Glucans; C089359:K1 killer toxin; D055646:Killer Factors, Yeast; D009183:Mycotoxins; D047071:beta-Glucans; C064197:beta-1,6-glucan; C033363:beta-1,3-glucan