Centromere domain organization and histone modifications
Centromere domain organization and histone modifications
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DOI：
10.1590/s0100-879x2002000500001
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发表时间：
2002-05-01
影响因子：
2.3
通讯作者：
Ekwall, K.
中科院分区：
文献类型：
--
作者：
Bjerling, P.;Ekwall, K.
着丝粒的功能需要几个子功能的适当协调，如动粒组装，姐妹染色单体凝聚力，结合的动粒微管，姐妹动粒的方向相反的纺锤体极，和他们的运动向纺锤体极。着丝粒结构似乎是组织在不同的，可分离的域，以完成这些功能。尽管着丝粒功能具有保守性，但在酵母酿酒酵母和粟酒裂殖酵母、果蝇黑腹果蝇和人类中形成着丝粒的DNA序列的分子遗传学定义揭示了在着丝粒DNA序列水平上几乎没有保守性。同样在蛋白质水平上，几乎没有着丝粒蛋白在所有这四种生物中是保守的，并且许多是不同生物所特有的。对酵母S.通过电子显微镜和详细的免疫荧光显微镜的果蝇着丝粒的粟酒裂殖子的研究，揭示了这些着丝粒和人类着丝粒之间在整体结构水平上的惊人相似性。着丝粒的结构组织通常是多层的，具有异染色质结构域和中央核心/内板区域，其包含动粒的外板结构。越来越清楚的是，着丝粒结构的组装和功能的关键因素是存在于着丝粒异染色质和中央核心的染色质中的特化历史和修饰的组蛋白。因此，尽管定义着丝粒的DNA序列和蛋白质存在差异，但在进化上不同的真核生物中，着丝粒之间存在总体结构相似性。
Centromere function requires the proper coordination of several subfunctions, such as kinetochore assembly, sister chromatid cohesion, binding of kinetochore microtubules, orientation of sister kinetochores to opposite spindle poles, and their movement towards the spindle poles. Centromere structure appears to be organized in different, separable domains in order to accomplish these functions. Despite the conserved nature of centromere functions, the molecular genetic definition of the DNA sequences that form a centromere in the yeasts Saccharomyces cerevisiae and Schizosaccharomyces pombe, in the fruit fly Drosophila melanogaster, and in humans has revealed little conservation at the level of centromere DNA sequences. Also at the protein level few centromere proteins are conserved in all of these four organisms and many are unique to the different organisms. The recent analysis of the centromere structure in the yeast S. pombe by electron microscopy and detailed immunofluorescence microscopy of Drosophila centromeres have brought to light striking similarities at the overall structural level between these centromeres and the human centromere. The structural organization of the centromere is generally multilayered with a heterochromaun domain and a central core/inner plate region, which harbors the outer plate structures of the kinetochore. It is becoming increasingly clear that the key factors for assembly and function of the centromere structure are the specialized histories and modified histones which are present in the centromeric heterochromatin and in the chromatin of the central core. Thus, despite the differences in the DNA sequences and the proteins that define a centromere, there is an overall structural similarity between centromeres in evolutionarily diverse eukaryotes.