Magherini Francesca, Tani Chiara, Gamberi Tania, Caselli Anna, Bianchi Laura, Bini Luca, Modesti Alessandra
Dipartimento di Scienze Biochimiche, Università degli Studi di Firenze, Firenze, Italy.
Proteomics. 2007 May;7(9):1434-45. doi: 10.1002/pmic.200600796.
We identified the proteins involved during apoptosis induced by H2O2 in Saccharomyces cerevisiae, and analyzed the global protein pattern by 2-DE. We analyzed classical parameters of apoptosis such as chromatin condensation, DNA fragmentation, and morphology changes of cells. Exposure of yeast cells to nonphysiological doses of peroxides decreases the expression (or increases degradation) of enzymes involved in protection against oxidative stress. This leads the yeast cells to a reduction of their antioxidant defense and makes the cells more prone to apoptosis. In our data the down expression of peroxiredoxin II and GST I, could induce a perturbation of mitochondrial function with an alteration of permeability of the membrane leading to the mitochondria-mediated apoptosis. Moreover, we identified a new spot of a classical glycolytic enzyme: the glyceraldehyde 3-phosphate dehydrogenase during apoptosis. It is known that GAPDH is an extremely abundant glycolytic enzyme with multiple functions and that its overexpression is evident during apoptosis induced by a variety of stimuli. Our results confirm that it is a major intracellular messenger mediating apoptotic death and that this new spot of GAPDH could be an intracellular sensor of oxidative stress during apoptosis induced by H2O2 in S. cerevisiae.
我们鉴定了酿酒酵母中由过氧化氢诱导的细胞凋亡过程中涉及的蛋白质，并通过双向电泳分析了整体蛋白质模式。我们分析了细胞凋亡的经典参数，如染色质浓缩、DNA片段化和细胞形态变化。将酵母细胞暴露于非生理剂量的过氧化物会降低参与抗氧化应激保护的酶的表达（或增加其降解）。这导致酵母细胞的抗氧化防御能力下降，使细胞更容易发生凋亡。在我们的数据中，过氧化物酶II和谷胱甘肽S-转移酶I的表达下调，可能会引起线粒体功能紊乱，导致膜通透性改变，进而引发线粒体介导的凋亡。此外，我们在细胞凋亡过程中鉴定出一种经典糖酵解酶的新斑点：3-磷酸甘油醛脱氢酶。已知3-磷酸甘油醛脱氢酶是一种极其丰富且具有多种功能的糖酵解酶，在多种刺激诱导的细胞凋亡过程中其过表达很明显。我们的结果证实它是介导凋亡死亡的主要细胞内信使，并且这个新的3-磷酸甘油醛脱氢酶斑点可能是酿酒酵母中过氧化氢诱导的细胞凋亡过程中氧化应激的细胞内传感器。
