SATB2 interacts with chromatin-remodeling molecules in differentiating cortical neurons
SATB2 interacts with chromatin-remodeling molecules in differentiating cortical neurons
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DOI：
10.1111/j.1460-9568.2008.06061.x
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发表时间：
2008-02-01
影响因子：
3.4
通讯作者：
Agoston, Denes V.
中科院分区：
文献类型：
--
作者：
Gyorgy, Andrea B.;Szemes, Marianna;Agoston, Denes V.
在我们寻找神经元分化的发育调节因子的过程中，我们鉴定出了富含特殊AT序列结合蛋白（SATB）2，它在发育中的大鼠新皮质中特异性表达，并与富含AT的DNA元件结合。在此我们研究了SATB2的调节功能是否涉及富含AT的DNA位点的染色质重塑。利用识别的DNA亲和预孵育特异性试验以及染色质免疫沉淀进行的体外和体内实验表明，SATB2特异性地与组蛋白去乙酰化酶1和转移相关蛋白2结合，它们是核小体重塑和组蛋白去乙酰化酶复合物的成员。双重免疫组织化学显示，在发育中的大鼠新皮质中，SATB2与这两种蛋白共同表达。利用细胞培养模型，我们发现曲古抑菌素A处理（其阻断组蛋白去乙酰化酶的活性）可逆转SATB2的富含AT的双链DNA依赖性阻遏效应。这些发现表明SATB2的分子调节功能涉及染色质结构的改变。对来自SATB2突变体和野生型动物的皮质进行的半定量染色质免疫沉淀分析表明，在敲除大脑中，SATB2在染色质重塑复合物中被富含AU元件的RNA结合蛋白1所取代，这是另一种也在分化的皮质神经元中表达的富含AT的DNA结合蛋白。这些结果表明，由于染色质重塑复合物中存在不同的富含AT的DNA结合蛋白而导致的染色质结构改变，可能导致在SATB2突变体动物中观察到的发育异常。这些发现也提出了一个有趣的可能性，即SATB2与其他富含AT的DNA结合蛋白一起，参与在皮质发育过程中介导表观遗传影响。
During our search for developmental regulators of neuronal differentiation, we identified special AT-rich sequence-binding protein (SATB)2 that is specifically expressed in the developing rat neocortex and binds to AT-rich DNA elements. Here we investigated whether the regulatory function of SATB2 involves chromatin remodeling at the AT-rich DNA site. In-vitro and in-vivo assays using a DNA affinity pre-incubation specificity test of recognition and chromatin immunoprecipitation showed that SATB2 specifically binds to histone deacetylase 1 and metastasis-associated protein 2, members of the nucleosome-remodeling and histone deacetylase complex. Double immunohistochemistry showed that, in the developing rat neocortex, SATB2 is coexpressed with both proteins. Using a cell culture model, we showed that trichostatin A treatment, which blocks the activities of histone deacetylases, reverses the AT-rich dsDNA-dependent repressor effect of SATB2. These findings suggested that the molecular regulatory function of SATB2 involves modification of the chromatin structure. Semi-quantitative chromatin immunoprecipitation analysis of cortices from SATB2 mutant and wild-type animals indicated that, in the knock-out brains, SATB2 is replaced in the chromatin-remodeling complex by AU-rich element RNA binding protein 1, another AT-rich DNA binding protein also expressed in differentiating cortical neurons. These results suggested that an altered chromatin structure, due to the presence of different AT-rich DNA binding proteins in the chromatin-remodeling complex, may contribute to the developmental abnormalities observed in the SATB2 mutant animals. These findings also raised the interesting possibility that SATB2, along with other AT-rich DNA binding proteins, is involved in mediating epigenetic influences during cortical development.