组蛋白不同乙酰化位点突变对酵母细胞生长和Ssa3、Gal1基因表达的影响  

Effects of Different Mutations in Histone Acetylation Site on Ssa3 and Gal1 Transcription and Growth of Yeast Cells

作　　者：李芬[1] 孔艳[1] 张帅[1] 马瑜[1] 胡岩岩[1] 

机构地区：[1]河南师范大学生命科学学院,新乡453007

出　　处：《中国生物化学与分子生物学报》2010年第9期822-827,共6页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金(No.30600343);河南省重点科技攻关(No.092102310026);河南省重点学科建设项目资助~~

摘　　要：组蛋白乙酰化对基因表达和细胞生长非常重要.为揭示组蛋白H3K14和H4K8的乙酰化修饰对不同条件下细胞生长和Ssa3、Gal1基因表达的重要性及二者功能差异.构建了H3K14、H4K8分别突变为精氨酸的单突变株S14、S8及二者同时突变的双突变株D814,并对其在正常、高温、咖啡因存在等条件下生长及Ssa3、Gal1表达进行比较.结果表明,所有突变株对咖啡因敏感性增加;D814对温度敏感,且在供试条件下其生长及Ssa3和Gal1激活均明显慢于野生型和单突变株;除半乳糖和葡萄糖为单一碳源,30℃时两单突变株差别不大外,其它条件下S8生长及Ssa3和Gal1激活均慢于S14.表明H3K14、H4K8乙酰化对细胞生长和适应不利环境非常重要,而且在对不利条件的快速适应方面,H4K8的乙酰化修饰可能更为重要.组蛋白突变株的表型缺陷是因该条件下细胞生存所必需的基因激活延迟所致.Histone acetylated modifications have great impacts on gene expression and cell growth. To evaluate the roles of H3 K14 and H4 K8 acetylation in Ssa3, Gall expression and yeast growth. We established yeast strains carrying either or both mutations of lysine 14 and 8 to arginine in the tail of histone H3 and H4 to mimick positively charged unacetylated lysines. We then characterized the effects of these mutations on Ssa3 and Gall gene expression and cell growth using semi-quantitative RT-PCR at different conditions of normal, high temperature and caffeine exposure. Our results showed that three mutants affected histone acetylation exhibited more significant growth defects on Ssa3, Gall than those of wild type, and the impact of H4 K8→R / H3 K14→R double mutant strain D814 displayed the most severe phenotype. The defect of H4 K8→R mutants S8 was more severe than those of H3 K14→ R mutants S14, except for the growth on galactose and glucose plates at 30~C. As the H3 K14 and H4 K8 acetylation are important for the survival and growth of yeast in unfavorable conditions, histone acetylation at different sites are expected to have different effects on the gene expression in vivo. The H4 K8 acetylation may be more important for the adaptation for harsh condition. The histone mutant strains with defective phenotype could result in the slow activation of induciable gene that was essential for survival at abnormal conditions.

关 键 词：组蛋白乙酰化 赖氨酸 突变株 细胞生长 基因表达 

分 类 号：Q341[生物学—遗传学]