We previously reported that Saccharomyces cerevisiae mutants in mRNA decapping and mutants expressing a truncated form of the KILSM4 gene, showed premature senescence and apoptotic phenotypes. Here, we show that this truncated protein is dispersed in the cytoplasm and does not assemble to P-bodies. As reported in decapping mutants, we observed an increase in the number of P-bodies suggesting that the truncation of the protein impairs this process. The number of P-bodies also increases after oxidative stress and is not dependent on the meta-caspase gene YCA1, placing this phenomenon upstream to the onset of apoptosis. (c) 2007 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.