Spatiotemporal alteration of chromatin structure at promoter regions

我们分析了芳香酶基因(CYP19A1)的染色质结构，该基因由三个主要启动子转录而成。我们新的沉降速度离心法发现，工作启动子完全由开放染色质组成。相反，在未使用的启动子周围观察到组蛋白H3赖氨酸27的三甲基化，这是已知的转录负性标记，表明多组合蛋白选择性地抑制启动子。

We analyzed chromatin structure responsible to the alternativepromoter usage of the aromatase gene (CYP19A1), which is transcribed from three majorpromoters. Our novel method using sedimentation velocity centrifugation revealed thatworking promoters were exclusively composed of open chromatin. In contrast, therecruitment of trimethylation of histone H3 lysine 27, which is known as a negative markfor transcription, was observed around unused promoters, suggesting that polycombproteins repressed the promoters selectively.