RNA聚合酶I传播rDNA静态染色质的单向传播
Stephen W Buck1, Joseph J Sandmeier, Jeffrey S Smith
1Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, VA 22908, USA.
Cell
|January 1, 2003
概括
在酵母体中,核糖体DNA (rDNA) 沉默以方向传播,需要RNA聚合酶I转录和SIR2. 这个过程限制了重组并影响了寿命.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
背景情况:
- 已知Saccharomyces cerevisiae中的核糖体DNA (rDNA) 诱导RNA聚合酶II基因的转录沉默.
- 这种SIR2-依赖的抑制 (rDNA沉默) 对于限制rDNA重组和调节寿命至关重要.
研究的目的:
- 研究酵母菌中rDNA沉默的传播动态和调控机制.
- 确定RNA聚合酶I (Pol I) 转录在rDNA沉默的建立和方向性中的作用.
主要方法:
- 对基因沉默和扩散到相邻的独特序列的分析.
- 监测与SIR2活性相关的基因组脱乙烯化 (H3和H4).
- 调查SIR2过度表达对沉默传播的影响.
- 评估Pol I转录对rDNA沉默的要求.
主要成果:
- rDNA沉默扩散到Pol I转录的下游的中心-近端单一序列,但不会扩散到上游的端粒-近端序列.
- 沉默传播与SIR2-依赖的素H3和H4脱乙化有关,并且可以通过SIR2过度表达来增强.
- rDNA沉默取决于Pol I转录,其传播方向是由Pol I转录的方向决定的.
结论:
- 聚I转录在确定rDNA沉默传播的方向性方面发挥着至关重要的作用.
- 这些发现揭示了一个新的机制,即Pol I转录决定了表观遗传沉默边界,影响了rDNA的稳定性和寿命.
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