title: Genome-wide screen of Saccharomyces cerevisiae for killer toxin HM-1 resistance.
abstract: We screened a set of Saccharomyces cerevisiae deletion mutants for resistance to killer toxin HM-1, which kills susceptible yeasts through inhibiting 1,3-beta-glucan synthase. By using HM-1 plate assay, we found that eight gene-deletion mutants had higher HM-1-resistance compared with the wild-type. Among these eight genes, five--ALG3, CAX4, MNS1, OST6 and YBL083C--were associated with N-glycan formation and maturation. The ALG3 gene has been shown before to be highly resistant to HM-1. The YBL083C gene may be a dubious open reading frame that overlaps partially the ALG3 gene. The deletion mutant of the MNS1 gene that encodes 1,2-alpha-mannosidase showed with a 13-fold higher HM-1 resistance compared with the wild-type. By HM-1 binding assay, the yeast plasma membrane fraction of alg3 and mns1 cells had less binding ability compared with wild-type cells. These results indicate that the presence of the terminal 1,3-alpha-linked mannose residue of the B-chain of the N-glycan structure is essential for interaction with HM-1. A deletion mutant of aquaglyceroporin Fps1p also showed increased HM-1 resistance. A deletion mutant of osmoregulatory mitogen-activated protein kinase Hog1p was more sensitive to HM-1, suggesting that high-osmolarity glycerol pathways plays an important role in the compensatory response to HM-1 action.
authors.affiliation: Department of Biochemistry, Faculty of Pharmaceutical Sciences, Niigata University of Pharmacy and Applied Life Sciences, 265-1 Higashijima, Akiha-ku, Niigata 956-8603, Japan. miyamoto@nupals.ac.jp
authors.forename: Masahiko
authors.initials: M
authors.lastname: Miyamoto
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Furuichi
authors.forename: Tadazumi
authors.initials: T
authors.lastname: Komiyama
mesh_terms: D002473:Cell Wall / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D005800:Genes, Fungal; D016681:Genome, Fungal; D005964:Glucosyltransferases / Q000037:antagonists & inhibitors / Q000235:genetics; D055646:Killer Factors, Yeast / Q000378:metabolism*; D008364:Mannosyltransferases / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D016366:Open Reading Frames; D012441:Saccharomyces cerevisiae / Q000235:genetics* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D055646:Killer Factors, Yeast; D008565:Membrane Proteins; D029701:Saccharomyces cerevisiae Proteins; C104466:ALG3 protein, S cerevisiae; D005964:Glucosyltransferases; D008364:Mannosyltransferases; C020570:1,3-beta-glucan synthase