Dissecting toxin immunity in virus-infected killer yeast uncovers an intrinsic strategy of self-protection.

ABSTRACT: Toxin-secreting "killer" yeasts were initially identified >40 years ago in Saccharomyces cerevisiae strains infected with a double-stranded RNA "killer" virus. Despite extensive research conducted on yeast killer toxins, the mechanism of protecting immunity by which toxin-producing cells evade the lethal activities of these proteins has remained elusive. Here, we identify the mechanism leading to protecting immunity in a killer yeast secreting a viral alpha/beta protein toxin (K28) that enters susceptible cells by receptor-mediated endocytosis and, after retrograde transport into the cytosol, blocks DNA synthesis, resulting in both cell-cycle arrest and caspase-mediated apoptosis. We demonstrate that toxin immunity is effected within the cytosol of a toxin-secreting yeast and occurs via th

SUBMITTER: Breinig F 

PROVIDER: S-EPMC1533781 | biostudies-literature | 2006 Mar

REPOSITORIES: biostudies-literature