AT-hook proteins stimulate induction of senescence markers triggered by 5-bromodeoxyuridine in mammalian cells
AT-hook proteins stimulate induction of senescence markers triggered by 5-bromodeoxyuridine in mammalian cells
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DOI：
10.1016/j.exger.2003.10.008
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发表时间：
2004-02-01
影响因子：
3.9
通讯作者：
Ayusawa, D
中科院分区：
文献类型：
--
作者：
Satou, W;Suzuki, T;Ayusawa, D
5-溴脱氧尿苷（BrdU）在哺乳动物细胞中诱导类似细胞衰老的现象。为了解决这一现象的潜在分子机制，我们评估了AT-钩蛋白结合特定AT-丰富序列的小沟的作用。我们在HeLa细胞中以强力霉素依赖性方式表达了DsRed标记的HMGI、MATH 2和MATH 20蛋白。这些蛋白质的适度表达显示对细胞没有明显的影响，尽管高水平的表达对细胞有毒性。相反，它们在低浓度BrdU存在下的适度表达类似地并且剂量依赖性地诱导衰老标记物被检查，尽管相同浓度的BrdU单独没有显示出明显的效果。在这两种情况下，DsRed荧光主要观察到Hoechst 33342染色区域上的病灶或强点。这些分布模式没有改变，通过添加BrdU。由于AT-钩结构域可以取代染色质压缩蛋白预绑定在AT丰富的序列，这些结果表明，染色质解包的因素之一，刺激衰老标志物在人类细胞中的表达。(C)2003年爱思唯尔公司All rights reserved.
5-Bromodeoxyuridine (BrdU) induces a phenomenon similar to cellular senescence in mammalian cells. To address an underlying molecular mechanism in this phenomenon, we assessed the role of AT-hook proteins that bind to the minor grooves of specific AT-rich sequences. We expressed DsRed-tagged HMGI, MATH2, and MATH20 proteins in HeLa cells in a doxycycline dependent manner. Modest expression of these proteins revealed no apparent effect on the cells although high levels of expression were toxic to the cells. In contrast, their modest expression in the presence of low concentrations of BrdU similarly and dose-dependently induced senescence markers examined, although the same concentrations of BrdU alone showed no obvious effect. In both cases, DsRed fluorescence was mainly observed as foci or intense dots on Hoechst 33342-staining regions. These distribution patterns were not changed by addition of BrdU. Since AT-hook domains can displace chromatin compacting proteins pre-bound on AT-rich sequences, these results suggest that chromatin unpacking is one of the factors stimulating expression of the senescence markers in human cells. (C) 2003 Elsevier Inc. All rights reserved.