Immunity to K1 killer toxin: internal TOK1 blockade.
K1 killer strains of Saccharomyces cerevisiae harbor RNA viruses that mediate secretion of K1, a protein toxin that kills virus-free cells. Recently, external K1 toxin was shown to directly activate TOK1 channels in the plasma membranes of sensitive yeast cells, leading to excess potassium flux and cell death. Here, a mechanism by which killer cells resist their own toxin is shown: internal toxin inhibits TOK1 channels and suppresses activation by external toxin.
Sesti
F
F
Departments of Pediatrics and Cellular and Molecular Physiology, Boyer Center for Molecular Medicine, Yale University School of Medicine, 295 Congress Avenue, New Haven, CT 06536, USA.
Shih
T M
TM
Nikolaeva
N
N
Goldstein
S A
SA
D015966:Gene Expression Regulation, Fungal; D007113:Immunity, Innate / Q000502:physiology; D015640:Ion Channel Gating / Q000502:physiology; D055646:Killer Factors, Yeast; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009154:Mutation / Q000502:physiology; D009183:Mycotoxins / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000821:virology*; D029701:Saccharomyces cerevisiae Proteins
C089359:K1 killer toxin; D055646:Killer Factors, Yeast; D009183:Mycotoxins; D015221:Potassium Channels; D029701:Saccharomyces cerevisiae Proteins; C095220:TOK1 protein, S cerevisiae; D011188:Potassium