Histone acetylation: A possible mechanism for the inheritance of cell memory at mitosis
Histone acetylation: A possible mechanism for the inheritance of cell memory at mitosis
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DOI：
10.1002/bies.950190111
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发表时间：
1997-01-01
期刊：
影响因子：
4
通讯作者：
Jeppesen, P
中科院分区：
文献类型：
--
作者：
Jeppesen, P
免疫荧光标记表明，人类中期染色体含有超乙酰化组蛋白H4。除了雌性细胞中无活性的X染色体之外，其中大部分组蛋白H4乙酰化不足，H4超乙酰化沿着染色体不均匀分布，并聚集在细胞学上可分辨的染色质结构域中，这些结构域通常与常规染色的R带相对应。最强的免疫标记通常在T带中发现，T带是具有最高GC含量的强R带的子集。大多数定位的基因也出现在R带区域，T带的基因密度最高。这些观察结果与组蛋白H4的超乙酰化标记中期染色体上潜在活性基因序列的位置的模型一致。由于乙酰化在有丝分裂期间维持，后代细胞接收细胞分裂前存在于亲本染色体上的组蛋白H4乙酰化模式的印记。组蛋白乙酰化可以提供一种传播细胞记忆的机制，细胞记忆被定义为通过细胞谱系维持基因表达的承诺状态。
Immunofluorescent labelling demonstrates that human metaphase chromosomes contain hyperacetylated histone H4. With the exception of the inactive X chromosome in female cells, where the bulk of histone H4 is underacetylated, H4 hyperacetylation is non-uniformly distributed along the chromosomes and clustered in cytologically resolvable chromatin domains that correspond, in general, with the R-bands of conventional staining. The strongest immunolabelling is often found in T-bands, the subset of intense R-bands having the highest GC content. The majority of mapped genes also occurs in R-band regions, with the highest gene density in T-bands. These observations are consistent with a model in which hyperacetylation of histone H4 marks the position of potentially active gene sequences on metaphase chromosomes. Since acetylation is maintained during mitosis, progeny cells receive an imprint of the histone H4 acetylation pattern that was present on the parental chromosomes before cell division. Histone acetylation could provide a mechanism for propagating cell memory, defined as the maintenance of committed states of gene expression through cell lineages.