Aging
Old age in yeast cells results in insensitivity to mating pheromone. Reduced activity of the histone deactylase Sir2 and consequent alteration of chromatin at mating loci have been implicated in the decreased sensitivity of old cells. However, Schlissel et al. found a different mechanism in the yeast strains that they studied (see the Perspective by Gitler and Jarosz). Proper response to mating pheromone requires arrest of the cell cycle mediated by an RNA-binding protein, Whi3. If aggregation of Whi3 in old cells was inhibited by deletion of a glutamine-rich region that promotes aggregation, loss of sensitivity to mating pheromone was partially prevented, and replicative life span was slightly increased.
Science , this issue p. [1184][1]; see also p. [1126][2]
[1]: /lookup/doi/10.1126/science.aaj2103
[2]: /lookup/doi/10.1126/science.aam9740