Single-molecule imaging of the transcription factor SRF reveals prolonged chromatin-binding kinetics upon cell stimulation
Single-molecule imaging of the transcription factor SRF reveals prolonged chromatin-binding kinetics upon cell stimulation
复制标题
DOI：
10.1073/pnas.1812734116
复制
发表时间：
2019-01-15
影响因子：
11.1
通讯作者：
Knoell, Bernd
中科院分区：
文献类型：
--
作者：
Hipp, Lisa;Beer, Judith;Knoell, Bernd
血清反应因子（SRF）介导几乎任何细胞类型中的立即早期基因（IEG）和细胞骨架基因表达程序。到目前为止，SRF转录动力学尚未在单分子分辨率下进行研究。我们提供了成纤维细胞和原代神经元中单个Halo标记的SRF分子的研究。在这两种细胞类型中，SRF分子的单个结合事件分离成三种染色质停留时间制度，短，中间和长结合，表明细胞类型独立的SRF属性。染色质停留时间的长结合部分是1分钟，在静止的细胞和刺激后显着增加。刺激还增强了两种细胞类型在特定时间点（20和60分钟）的长结合SRF分数。这些峰与SRF辅因子MRTF-A和MRTF-B（肌红蛋白相关转录因子）的激活相关。信号通路和辅因子的干扰表明，肌动蛋白信号，MAP激酶和MRTF的SRF染色质占用的调制。
Serum response factor (SRF) mediates immediate early gene (IEG) and cytoskeletal gene expression programs in almost any cell type. So far, SRF transcriptional dynamics have not been investigated at single-molecule resolution. We provide a study of single Halo-tagged SRF molecules in fibroblasts and primary neurons. In both cell types, individual binding events of SRF molecules segregated into three chromatin residence time regimes, short, intermediate, and long binding, indicating a cell type-independent SRF property. The chromatin residence time of the long bound fraction was up to 1 min in quiescent cells and significantly increased upon stimulation. Stimulation also enhanced the long bound SRF fraction at specific timepoints (20 and 60 min) in both cell types. These peaks correlated with activation of the SRF cofactors MRTF-A and MRTF-B (myocardin-related transcription factors). Interference with signaling pathways and cofactors demonstrated modulation of SRF chromatin occupancy by actin signaling, MAP kinases, and MRTFs.