Dynamic associations of heterochromatin protein 1 with the nuclear envelope
Dynamic associations of heterochromatin protein 1 with the nuclear envelope
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DOI：
10.1093/emboj/19.23.6558
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发表时间：
2000-12-01
期刊：
影响因子：
11.4
通讯作者：
Georgatos, SD
中科院分区：
文献类型：
--
作者：
Kourmouli, N;Theodoropoulos, PA;Georgatos, SD
为了研究哺乳动物HP 1蛋白的动力学，我们将重组形式的mHP 1 α、M31和M32显微注射到活细胞的细胞质中。正如从先前的研究中可以预期的，三种融合蛋白被有效地转运到细胞核中并靶向特定的染色质区域。然而，在掺入这些区域之前，外源性蛋白质积累在外周区并与核膜紧密结合。这种短暂的关联没有发生时，细胞用去乙酰化酶抑制剂处理，表明乙酰化抑制的相互作用。与这些观察结果一致，重组HP 1蛋白表现出与纯化的核膜的饱和结合，并以边缘样方式染色去污剂透化细胞的细胞核。与各种M31突变体的竞争实验允许映射的N-末端区域内，包括chromodomain的核膜结合位点。代表该区域的His（6）标记肽抑制了凝聚染色体表面周围LAP 2 β和B型核纤层蛋白的募集，表明HP 1蛋白参与核膜重组。
To study the dynamics of mammalian HP1 proteins we have microinjected recombinant forms of mHP1 alpha, M31 and M32 into the cytoplasm of living cells. As could be expected from previous studies, the three fusion proteins were efficiently transported into the nucleus and targeted specific chromatin areas. However, before incorporation into these areas the exogenous proteins accumulated in a peripheral zone and associated closely,vith the nuclear envelope. This transient association did not occur when the cells were treated with deacetylase inhibitors, indicating an acetylation-inhibited interaction. In line with these observations, recombinant HP1 proteins exhibited saturable binding to purified nuclear envelopes and stained the nuclei of detergent-permeabilized cells in a rim-like fashion. Competition experiments with various M31 mutants allowed mapping of the nuclear envelope-binding site within an N-terminal region that includes the chromodomain. A His(6)-tagged peptide representing this region inhibited recruitment of LAP2 beta and B-type lamins around the surfaces of condensed chromosomes, suggesting involvement of HP1 proteins in nuclear envelope reassembly.