热休克诱导细胞周期素D1表达水平降低的转录调控机制

Mechanism of heat shock-induced transcriptional inhibition of cyclinD1 expression

目的:研究人的细胞周期素D1基因启动子热休克效应的表达调控机制.方法:以RT-PCR技术研究细胞周期素D1mRNA水平的变化;构建一系列人细胞周期素D1基因启动子报告基因质粒.通过报告基因方法确认细胞周期素D1启动子的热休克效应区.应用染色质免疫沉技术检测核心启动子区域的组蛋白乙酰化修饰情况.结果:热休克造成细胞周期素D1mRNA水平下降;报告基因结果显示人细胞周期素D1基因的热休克的效应区位于-50～+141bp范围.核心启动子区组蛋白H3第九位赖氨酸乙酰化程度降低.结论:热休克抑制人的细胞周期素D1基因的启动子转录活性,其效应区位于核心启动子的-50～+141bp范围.热休克效应与核心启动子区的组蛋白乙酰化程度下降有关.

AIM：To investigate the heat shock response mechanism of human cyclin D1 promoter. METHODS：The mRNA level is detected by RT-PCR. The CAT reporter gene plasmids driven by the series of human cyclin D1 promoter truncations are constructed into pREP4-m-CAT vector. The responsible region is investigated by reporter gene analysis. The histone acetylation status is detected by chromatin immunoprecipitation （ChIP）. RESULTS：The mRNA level of cyclin D1 decreased under heat shock. This transcription depression is promoter activity dependent and the heat shock response region is located in - 50 - ＋ 141 region in which the Ac-H3k9 modification decreased. CONCLUSION ： These results reveal that the heat inhibits cyclin D1 transcription involves its -50 - ＋ 141 region. The histone acetylation modification decreased under heat treatment which may be responsible for the heat shock response.