Characterization of the stability and folding of H2A.Z chromatin particles -: Implications for transcriptional activation
Characterization of the stability and folding of H2A.Z chromatin particles -: Implications for transcriptional activation
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DOI：
10.1074/jbc.m108217200
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发表时间：
2001-11-09
影响因子：
4.8
通讯作者：
Ausió, J
中科院分区：
文献类型：
--
作者：
Abbott, DW;Ivanova, VS;Ausió, J
使用这些组蛋白的重组形式和在适当的DNA模板上重构的天然组蛋白H2 B/H3/H4补体获得H2A.Z和H2A.1核小体核心颗粒和核小体阵列。使用天然聚丙烯酰胺凝胶电泳和DNA酶I足迹分析重构的核小体核心颗粒表明，H2A.Z核小体核心颗粒与其H2A.1或天然鸡红细胞对应物在结构上几乎无法区分。虽然该结果与最近公布的H2A.Z核小体核心颗粒的晶体学结构（Suto，R. K.，克拉克森，M J.，Tremethick，D. J.，和Luger，YL（2000）Nat.Struct.Biol.7，1121 -1124），这些颗粒的沉降系数的离子强度依赖性表现出显著的不稳定性，这很可能是组蛋白H2 A.Z-H213二聚体与核小体结合较不紧密的结果。H2A.Z 208-12是一种由来自海胆Lytechinus variegatus 5 S rRNA基因的208个碱基对序列的12个串联重复序列组成的DNA模板，在不存在组蛋白HI的情况下重建了染色体复合物，其分析性超电泳分析表明，它们的NaCl依赖性折叠能力显著降低。这些结果支持组蛋白H2A.Z变体可能发挥染色质去稳定作用的观点，这可能对转录激活很重要。
H2A.Z and H2A.1 nucleosome core particles and oligonucleosome arrays were obtained using recombinant versions of these histones and a native histone H2B/H3/H4 complement reconstituted onto appropriate DNA templates. Analysis of the reconstituted nucleosome core particles using native polyacrylamide gel electrophoresis and DNase I footprinting showed that H2A.Z nucleosome core particles were almost structurally indistinguishable from its H2A.1 or native chicken erythrocyte counterparts. While this result is in good agreement with the recently published crystallographic structure of the H2A.Z nucleosome core particle (Suto, R. K., Clarkson, M J., Tremethick, D. J., and Luger, YL (2000) Nat. Struct. Biol. 7,1121-1124), the ionic strength dependence of the sedimentation coefficient of these particles exhibits a substantial destabilization, which is most likely the result of the histone H2A.Z-H213 dimer binding less tightly to the nucleosome. Analytical ultracentrifuge analysis of the H2A.Z 208-12, a DNA template consisting of 12 tandem repeats of a 208-base pair sequence derived from the sea urchin Lytechinus variegatus 5 S rRNA gene, reconstituted oligonucleosome complexes in the absence of histone HI shows that their NaCl-dependent folding ability is significantly reduced. These results support the notion that the histone H2A.Z variant may play a chromatin-destabilizing role, which may be important for transcriptional activation.