转录抑制剂SIR3从端粒异色染色体中扩散
A Hecht1, S Strahl-Bolsinger, M Grunstein
1Department of Biological Chemistry, UCLA School of Medicine and Molecular Biology Institute, Los Angeles, California 90095, USA.
Nature
|September 5, 1996
概括
SIR3是酵母异染色素的关键结构组成部分,与其他蛋白质和组织蛋白形成大型复合体. 这种蛋白质从端粒扩散,抑制邻近的基因并建立一个沉默的染色质结构.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 酵母生物学的酵母生物学
背景情况:
- 在Saccharomyces cerevisiae中的端粒和HM位点表现出转录抑制和异色素蛋白结构.
- 转化作用因子RAP1,SIR3和SIR4对于端粒和HM沉默至关重要.
- 这些因素对基斯依赖抑制的确切机制尚不清楚.
研究的目的:
- 阐明SIR3在建立和维持异色素蛋白结构中的作用.
- 为了研究SIR3与其他沉默因子和基因组的相互作用.
- 为了确定SIR3在酵母染色体内的体内定位和扩散.
主要方法:
- 同免疫沉测试用于识别蛋白质复合体.
- 在体外相互作用研究与 histone amino termini.
- 染色体交叉连接实验以评估体内本地化.
- 基因表达分析以评估沉默.
主要成果:
- SIR3与SIR4,RAP1和基因组一起形成大型的染色质相关蛋白质复合体.
- 在SIR3的作用下,它与素H3和H4氨基末端相互作用.
- 在体内,SIR3定位在HMRa,HMLalpha和端粒.
- 过度表达SIR3导致其扩散到相邻的染色体.
结论:
- SIR3是酵母异色素的结构组成部分.
- 通过沿着染色体扩散,SIR3通过介导基因抑制.
- 大型蛋白质复合物的形成对于异色染色素的建立和维护至关重要.
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