Mating-type locus control of killer toxins from Kluyveromyces lactis and Pichia acaciae
Killer-toxin complexes produced by Kluyveromyces lactis and Pichia acaciae inhibit cell proliferation of Saccharomyces cerevisiae. Analysis of their actions in haploid MAT[alpha] cells revealed that introduction of the opposite mating-type locus (MATa) significantly suppressed antizymosis. Together...
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Published in | FEMS yeast research Vol. 6; no. 3; pp. 404 - 413 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford, UK
Blackwell Publishing Ltd
01.05.2006
Oxford University Press |
Subjects | |
Online Access | Get full text |
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Summary: | Killer-toxin complexes produced by Kluyveromyces lactis and Pichia acaciae inhibit cell proliferation of Saccharomyces cerevisiae. Analysis of their actions in haploid MAT[alpha] cells revealed that introduction of the opposite mating-type locus (MATa) significantly suppressed antizymosis. Together with resistance expressed by MATa/MAT[alpha] diploids, the reciprocal action of MATa or MAT[alpha] in haploids of opposite mating types suggests that these killer toxins may be subject to MAT locus control. Congruently, derepressing the silent mating-type loci, HMR and HML, by removing individual components of the histone deacetylase complex Sir1[-]4, either by transposon-tagging or by chemically inactivating the histone deacetylase catalytic subunit Sir2, yields toxin resistance. Consistent with MAT control of toxin action, killer-toxin-insensitive S. cerevisiae mutants (kti) become mating-compromised despite resisting the toxins' cell-cycle effects. Mating inhibition largely depends on the time point of toxin application to the mating mixtures and is less pronounced in Elongator mutants, whose resistance to the toxins' cell-cycle effects is the result of toxin-target process deficiencies. In striking contrast, non-Elongator mutants defective in early-response events such as toxin import/activation hardly recover from toxin-induced mating inhibition. This study reveals a novel effect of yeast killer toxins on mating and sexual reproduction that is independent of their impact on cellular proliferation and cell-cycle progression. |
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Bibliography: | http://dx.doi.org/10.1111/j.1567-1364.2005.00006.x These two authors contributed equally. * Editor: Lex Scheffers |
ISSN: | 1567-1356 1567-1364 |
DOI: | 10.1111/j.1567-1364.2005.00006.x |