Department of Molecular Genetics, University of Toronto, Toronto, Ontario, Canada.
Dev Cell. 2012 Jul 17;23(1):35-44. doi: 10.1016/j.devcel.2012.05.005. Epub 2012 Jun 21.
Autophagy controls cellular catabolism in diverse eukaryotes and modulates programmed cell death in plants and animals. While studies of the unicellular yeast Saccharomyces cerevisiae have provided fundamental insights into the mechanisms of autophagy, the roles of cell death pathways in yeast are less well understood. Here, we describe widespread developmentally programmed nuclear destruction (PND) events that occur during yeast gametogenesis. PND is executed through apoptotic-like DNA fragmentation in coordination with an unusual form of autophagy that is most similar to mammalian lysosomal membrane permeabilization and mega-autophagy, a form of plant autophagic cell death. Undomesticated strains execute gametogenic PND broadly in maturing colonies to the apparent benefit of sibling cells, confirming its prominence during the yeast life cycle. Our results reveal that diverse cell-death-related processes converge during gametogenesis in a microbe distantly related to plants or animals, highlighting gametogenesis as a process during which programmed cell death mechanisms may have evolved.
自噬控制着不同真核生物的细胞分解代谢，并调节动植物中的程序性细胞死亡。虽然对单细胞酵母酿酒酵母的研究为自噬机制提供了基本的见解，但酵母中细胞死亡途径的作用还不太清楚。在这里，我们描述了在酵母配子发生过程中广泛发生的发育程序性核破坏（PND）事件。PND 通过与一种不寻常的自噬形式协调执行，这种自噬形式与哺乳动物溶酶体膜通透性和巨型自噬最相似，巨型自噬是植物自噬性细胞死亡的一种形式。非驯化菌株在成熟菌落中广泛执行配子发生 PND，显然对同胞细胞有益，这证实了它在酵母生命周期中的重要性。我们的结果表明，在与植物或动物亲缘关系较远的微生物中，不同的与细胞死亡相关的过程在配子发生过程中汇聚在一起，突出了配子发生作为程序性细胞死亡机制可能进化的过程。
