Durand-Dubief Mickaël, Ekwall Karl
Karolinska Institutet, Department of Biosciences and Medical Nutrition/School of Life Sciences, University College Sodertorn, Sweden.
Bioessays. 2008 Jun;30(6):526-9. doi: 10.1002/bies.20763.
The centromere is the region of the chromosome where the kinetochore forms. Kinetochores are the attachment sites for spindle microtubules that separate duplicated chromosomes in mitosis and meiosis. Kinetochore formation depends on a special chromatin structure containing the histone H3 variant CENP-A. The epigenetic mechanisms that maintain CENP-A chromatin throughout the cell cycle have been studied extensively but little is known about the mechanism that targets CENP-A to naked centromeric DNA templates. In a recent report published in Science, such de novo centromere assembly of CENP-A is shown to be dependent on heterochromatin and the RNA interference pathway.
着丝粒是染色体上形成动粒的区域。动粒是纺锤体微管的附着位点，在有丝分裂和减数分裂中分离复制后的染色体。动粒的形成依赖于一种特殊的染色质结构，该结构包含组蛋白H3变体CENP - A。在整个细胞周期中维持CENP - A染色质的表观遗传机制已得到广泛研究，但关于将CENP - A靶向裸露的着丝粒DNA模板的机制却知之甚少。在最近发表于《科学》杂志的一篇报告中，CENP - A的这种从头着丝粒组装被证明依赖于异染色质和RNA干扰途径。
