Single-molecule analysis of steroid receptor and cofactor action in living cells.
Single-molecule analysis of steroid receptor and cofactor action in living cells.
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DOI：
10.1038/ncomms15896
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发表时间：
2017-06-21
影响因子：
16.6
通讯作者：
Hager GL
中科院分区：
文献类型：
--
作者：
Paakinaho V;Presman DM;Ball DA;Johnson TA;Schiltz RL;Levitt P;Mazza D;Morisaki T;Karpova TS;Hager GL
基于群体的分析已被广泛用于研究转录因子（TF）与染色质的相互作用，并且通常被解释为静态和顺序结合。然而，荧光显微镜技术揭示了活细胞中TF的更动态的结合行为。在这里，我们分析了体内单分子跟踪的优势和局限性，并对四种类固醇受体和一些已知的辅因子的核内停留时间进行了全面分析。虽然绝对停留时间估计值可能取决于成像采集参数由于采样偏差，我们的研究结果表明，只有一小部分的因素是专门结合到染色质在任何给定的时间。有趣的是，糖皮质激素受体及其辅因子以不对称的方式影响彼此的停留时间。总的来说，我们的数据表明，在单分子水平上，TF-辅因子染色质相互作用是短暂的，而不是稳定的。转录因子（Transcription Factor，TF）被认为通过与靶DNA元件稳定结合来调节基因表达。在这里，作者使用单分子跟踪来分析类固醇受体TF的动态行为，并表明与染色质的大多数特异性相互作用是短暂和动态的。
Population-based assays have been employed extensively to investigate the interactions of transcription factors (TFs) with chromatin and are often interpreted in terms of static and sequential binding. However, fluorescence microscopy techniques reveal a more dynamic binding behaviour of TFs in live cells. Here we analyse the strengths and limitations of in vivo single-molecule tracking and performed a comprehensive analysis on the intranuclear dwell times of four steroid receptors and a number of known cofactors. While the absolute residence times estimates can depend on imaging acquisition parameters due to sampling bias, our results indicate that only a small proportion of factors are specifically bound to chromatin at any given time. Interestingly, the glucocorticoid receptor and its cofactors affect each other’s dwell times in an asymmetric manner. Overall, our data indicate transient rather than stable TF-cofactors chromatin interactions at response elements at the single-molecule level. Transcription factors (TFs) are thought to regulate gene expression by stably binding to target DNA elements. Here, the authors use single-molecule tracking to analyse the dynamic behaviour of steroid receptors TFs and show that most specific interactions with chromatin are transient and dynamic.