Beyond the Xi -: MacroH2A chromatin distribution and post-translational modification in an avian system
Beyond the Xi -: MacroH2A chromatin distribution and post-translational modification in an avian system
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DOI：
10.1074/jbc.m500170200
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发表时间：
2005-04-22
影响因子：
4.8
通讯作者：
Ausi贸, J
中科院分区：
文献类型：
--
作者：
Abbott, DW;Chadwick, BP;Ausi贸, J
MacroH 2A（mH 2A）是一种组蛋白变体，在哺乳动物雌性的失活X染色体中富集。为了表征该蛋白在其他核过程中的作用，我们从鸡肝中分离了染色质颗粒，鸡肝是一种不经历X失活的脊椎动物系统。染色质消化和分级分离研究确定mH 2A均匀分布在染色质结构的几个水平上，并稳定溶液中的核小体核心颗粒。然而，在染色体的水平上，选择性盐沉淀显示mH 2A和H1之间存在相互排斥的关系，这可能揭示了这些蛋白质之间的功能冗余。二维凝胶电泳表明存在一个主要的人口mH 2A含有核小体，这可能成为ADP-核糖基化。这份报告提供了新的线索如何mH 2A的分布和以前未识别的翻译后修饰可能有助于调节常染色体染色质的抑制。
MacroH2A (mH2A) is a histone variant that is enriched in the inactivated X-chromosomes of mammalian females. To characterize the role of this protein in other nuclear processes we isolated chromatin particles from chicken liver, a vertebrate system that does not undergo X-inactivation. Chromatin digestion and fractionation studies determined that mH2A is evenly distributed at several levels of chromatin structure and stabilizes the nucleosome core particle in solution. However, at the level of the chromatosome, selective salt precipitation showed the existence of a mutually exclusive relationship between mH2A and H1, which may reveal functional redundancy between these proteins. Two-dimensional gel electrophoresis demonstrated the presence of one major population of mH2A containing nucleosomes, which may become ADP-ribosylated. This report provides new clues into how mH2A distribution and a previously unidentified post-translational modification may help regulate the repression of autosomal chromatin.