Cell-Cycle-Coupled Structural Oscillation of Centromeric Nucleosomes in Yeast
Cell-Cycle-Coupled Structural Oscillation of Centromeric Nucleosomes in Yeast
复制标题
DOI：
10.1016/j.cell.2012.05.034
复制
发表时间：
2012-07-20
期刊：
影响因子：
64.5
通讯作者：
Gerton, Jennifer L.
中科院分区：
文献类型：
--
作者：
Shivaraju, Manjunatha;Unruh, Jay R.;Gerton, Jennifer L.
着丝粒是调节染色体分离的特殊染色体结构。着丝粒由组蛋白H3变体标记。在芽殖酵母中，组蛋白H3变体Cse 4存在于单个着丝粒核小体中。实验证据支持着丝粒核小体结构的几种不同模型。为了研究活酵母中Cse 4的拷贝数，我们开发了一种耦合荧光相关光谱和校准成像的方法。我们发现，着丝粒核小体有一个拷贝的Cse 4在大部分的细胞周期，而两个拷贝检测到在后期。Cse 4-Cse 4相互作用、Cse 4的掺入和后期Scm 3的缺失支持了后期偶联结构变化的提议。核小体重建和ChIP表明两种Cse 4结构都含有H2 A/H2 B。在白念珠菌中也观察到Cse 4强度增加和后期沉积。我们的实验证据支持酵母中着丝粒核小体结构的细胞周期偶联振荡。
The centromere is a specialized chromosomal structure that regulates chromosome segregation. Centromeres are marked by a histone H3 variant. In budding yeast, the histone H3 variant Cse4 is present in a single centromeric nucleosome. Experimental evidence supports several different models for the structure of centromeric nucleosomes. To investigate Cse4 copy number in live yeast, we developed a method coupling fluorescence correlation spectroscopy and calibrated imaging. We find that centromeric nucleosomes have one copy of Cse4 during most of the cell cycle, whereas two copies are detected at anaphase. The proposal of an anaphase-coupled structural change is supported by Cse4-Cse4 interactions, incorporation of Cse4, and the absence of Scm3 in anaphase. Nucleosome reconstitution and ChIP suggests both Cse4 structures contain H2A/H2B. The increase in Cse4 intensity and deposition at anaphase are also observed in Candida albicans. Our experimental evidence supports a cell-cycle-coupled oscillation of centromeric nucleosome structure in yeast.