Dynamics of protein binding to telomeres in living cells:: Implications for telomere structure and function
Dynamics of protein binding to telomeres in living cells:: Implications for telomere structure and function
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DOI：
10.1128/mcb.24.12.5587-5594.2004
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发表时间：
2004-06-01
影响因子：
5.3
通讯作者：
Zijlmans, JMJM
中科院分区：
文献类型：
--
作者：
Mattern, KA;Swiggers, SJJ;Zijlmans, JMJM
端粒蛋白在调节端粒DNA束的长度和防止端到端染色体融合方面起着重要的作用。在活细胞中，端粒组织和单个蛋白质如何参与不同的端粒功能在很大程度上是未知的。利用绿色荧光蛋白标记和光漂白技术，研究了人端粒DNA结合蛋白与端粒DNA在体内的相互作用。我们的研究结果表明，端粒蛋白以一种复杂的动态方式与端粒相互作用：TRF2在染色体末端保护和端粒长度稳态中具有双重作用，位于两个不同的端粒池中。其中一个组分（约73%）具有与TRF1相似的结合动力学（停留时间约为44 s）。有趣的是，TRF2的另一部分与假定的末端保护因子hPOT1结合的动力学相似（停留时间类似于11分钟）。我们的数据支持端粒的动态模型，其中染色体末端保护和端粒长度稳态是由端粒蛋白与端粒DNA的差异结合所控制的。
Telomeric proteins have an essential role in the regulation of the length of the telomeric DNA tract and in protection against end-to-end chromosome fusion. Telomere organization and how individual proteins are involved in different tellomere functions in living cells is largely unknown. By using green fluorescent protein tagging and photobleaching, we investigated in vivo interactions of human telomeric DNA-binding proteins with tellomeric DNA. Our results show that telomeric proteins interact with telomeres in a complex dynamic fashion: TRF2, which has a dual role in chromosome end protection and telomere length homeostasis, resides at tellomeres in two distinct pools. One fraction (similar to73%) has binding dynamics similar to TRF1 (residence time of similar to44 s). Interestingly, the other fraction of TRF2 binds with similar dynamics as the putative end-protecting factor hPOT1 (residence time of similar to11 min). Our data support a dynamic model of telomeres in which chromosome end-protection and telomere length homeostasis are governed by differential binding of telomeric proteins to telomeric DNA.