ste20基因突变抑制葡萄糖诱导的酿酒酵母细胞凋亡

近年来，酿酒酵母的细胞调亡研究取得了很大进展。多种因素可以诱导其调亡，譬如过氧化氢（H2O2）、醋酸、高渗透压和高盐浓度等。葡萄糖是酿酒酵母生长所必须的重要营养物质之一。同时，在其他营养元素缺乏的条件下，只用葡萄糖培养将迅速的诱导酿酒酵母的细胞凋亡。Ste20是PAK（p21 activated kinase）家族的成员，它参与酿酒酵母的信息素应答、假菌丝生长和侵入生长等途径。有研究表明，ste20突变株能抵抗由信息素和过氧化物诱导的细胞调亡。我们发现STE20基因突变也能抑制葡萄糖诱导的凋亡，用葡萄糖处理时，与野生型相比，ste20突变株细胞能保持完整的细胞膜和细胞核结构。H2O2诱导酿酒酵母细胞凋亡时，需要Ste20激酶磷酸化组蛋白H2B第十号丝氨酸（S10）。因此，葡萄糖诱导的酿酒酵母细胞凋亡作用可能通过类似于过氧化氢诱导的酿酒酵母细胞凋亡的途径进行的。

Saccharomyces cerevisiae ste20 Mutant Showing Resistance to Glucose-Induced Cell Death

Glucose is one of the most important nutrients for yeast growth, which induces cell death of S. cerevisiae in the absence of other nutrients to support growth. In the present study, we reported that the S. cerevisiae ste20 mutant was resistant to glucose-induced cell death. Cells of ste20 mutant that were treated with glucose maintained intact membrane and nuclei. Ste20 kinase phosphorylates histone H2B at serine 10 (S10) during hydrogen peroxide (H2O2)-induced cell death. Therefore, glucose-induced cell death (GICD) may be regulated via a similar pathway of H2O2-induced apoptosis.