Genes responsive to the addition of spermidine or spermine to a polyamine-deficient Saccharomyces cerevisiae mutant. Saccharomyces cerevisiae

The naturally occurring polyamines putrescine, spermidine or spermine are ubiquitous in all cells. Although polyamines have prominent regulatory roles in cell division and growth, precise molecular and cellular functions are not well established in vivo. In this work we have performed a microarray experiment in a polyamine mutant (delta-spe3 delta-fms1) strain to investigate the responsiveness of yeast genes to supplementation with spermidine and spermine. Expression analysis identified genes responsive to the addition of either excess spermidine (10-5 M) or spermine (10-5 M) compared to a control culture containing 10-8 M spermidine. 247 genes were up-regulated >2-fold, and 11 genes were up-regulated more than 10-fold after spermidine addition. Functional categorization of the genes showed induction of transport related genes, and genes involved in methionine, arginine, lysine, NAD and biotin biosynthesis. 268 genes were down-regulated more than 2-fold, and 6 genes were down-regulated more than 8-fold after spermidine addition. A majority of the down-regulated genes are involved in nucleic acid metabolism and various stress responses. In contrast, only few genes (18) were significantly responsive to spermine. Thus, results from global gene expression profiling demonstrate a more major role for spermidine in modulating gene expression in yeast than spermine. Overall design: 5 control replicates vs. 3 spermine (SP)-treated or 5 spermidine (SPD)-treated samples.

天然存在的多胺（polyamines）腐胺（putrescine）、亚精胺（spermidine）与精胺（spermine）广泛分布于所有细胞中。尽管多胺在细胞分裂与生长过程中具有显著的调控功能，但其在活体内的确切分子与细胞功能尚未得到明确阐释。本研究针对多胺缺陷型（delta-spe3 delta-fms1）酵母菌株开展微阵列（microarray）实验，以探究酵母基因对亚精胺与精胺补充处理的响应情况。相较于添加10^-8 M亚精胺的对照培养物，本研究通过表达分析鉴定出了对10^-5 M过量亚精胺或10^-5 M精胺处理产生响应的基因。添加亚精胺后，共有247个基因的表达水平上调超过2倍，其中11个基因的上调幅度超过10倍。对上述基因进行功能分类后发现，转运相关基因以及参与甲硫氨酸、精氨酸、赖氨酸、烟酰胺腺嘌呤二核苷酸（NAD）与生物素生物合成的基因均被显著诱导。添加亚精胺后，另有268个基因的表达水平下调超过2倍，其中6个基因的下调幅度超过8倍。此类下调基因大多参与核酸代谢与各类应激响应过程。与之相比，仅有18个基因对精胺处理产生显著响应。综上，全基因组表达谱分析结果表明，相较于精胺，亚精胺在调控酵母基因表达方面发挥更为核心的作用。实验整体设计：设置5个生物学重复的对照样本，分别与3个精胺（SP）处理组样本或5个亚精胺（SPD）处理组样本进行比较分析。