Plasticity of HP1 proteins in mammalian cells
Plasticity of HP1 proteins in mammalian cells
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DOI：
10.1242/jcs.012914
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发表时间：
2007-10-01
影响因子：
4
通讯作者：
Georgatos, Spyros D.
中科院分区：
文献类型：
--
作者：
Dialynas, George K.;Terjung, Stefan;Georgatos, Spyros D.
我们比较了内源性异染色质蛋白1(HP1)蛋白在不同上皮系、多能干细胞和胚胎成纤维细胞中的分布。同时，我们研究了新表达的HP1-GFP蛋白在缺乏HP1α和HP1β等位基因的细胞中的组装和动态，阻止在G1-S交界处的细胞，或者在HDAC和HAT抑制剂存在的情况下培养的细胞。结果揭示了一系列细胞类型和分化状态的特定模式，这些模式与异染色质中的“快”或“慢”亚基交换无关。此外，我们的观察表明，HP1伽马针对异染色点的靶向取决于HP1α和H1β，并且在体系结构水平上，HP1α是HP1家族中最多态的变体。这些数据为HP1在不断变化的微环境条件下的可塑性提供了证据，并为在分子水平上理解染色质动力学提供了一个新的概念框架。
We have compared the distribution of endogenous heterochromatin protein 1 ( HP1) proteins (alpha, beta and gamma) in different epithelial lines, pluripotent stem cells and embryonic fibroblasts. In parallel, we have interrogated assembly and dynamics of newly expressed HP1-GFP proteins in cells lacking both HP1 alpha and HP1 beta alleles, blocked at the G1-S boundary, or cultured in the presence of HDAC and HAT inhibitors. The results reveal a range of cell type and differentiation state-specific patterns that do not correlate with 'fast' or 'slow' subunit exchange in heterochromatin. Furthermore, our observations show that targeting of HP1 gamma to heterochromatic sites depends on HP1 alpha and H1 beta and that, on an architectural level, HP1 alpha is the most polymorphic variant of the HP1 family. These data provide evidence for HP1 plasticity under shifting microenvironmental conditions and offer a new conceptual framework for understanding chromatin dynamics at the molecular level.