Concentration- and chromosome-organization-dependent regulator unbinding from DNA for transcription regulation in living cells.
Concentration- and chromosome-organization-dependent regulator unbinding from DNA for transcription regulation in living cells.
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DOI：
10.1038/ncomms8445
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发表时间：
2015-07-06
影响因子：
16.6
通讯作者：
Chen P
中科院分区：
文献类型：
--
作者：
Chen TY;Santiago AG;Jung W;Krzemiński Ł;Yang F;Martell DJ;Helmann JD;Chen P
转录调控因子在操纵子位点的结合和解结合构成了基因调控的主要机制。虽然已知许多细胞因子调节它们的结合，但对细胞如何调节它们的非结合以进行调节知之甚少。利用纳米精度的单分子跟踪技术，我们研究了两种金属敏感转录调节因子在大肠杆菌活细胞中从DNA中的解结合动力学。我们发现，他们表现出不寻常的浓度依赖性解结合动力学从染色体识别位点在他们的载脂蛋白和全息形式。出乎意料的是，它们的解结合动力学进一步随着染色体浓缩的程度而变化，更令人惊讶的是，它们的脱辅基阻遏物与全激活物形式以相反的方式变化。这些研究结果表明，可能广泛相关的机制，在体内转录激活和失活之间的轻松切换，并在协调耐药基因的转录调控与细胞周期。 转录调控因子在操纵基因位点的结合和解结合调控基因表达。通过对金属敏感调节剂的单分子追踪，作者发现，解离动力学依赖于调节剂浓度和染色体凝聚，并随其金属结合状态而变化。
Binding and unbinding of transcription regulators at operator sites constitute a primary mechanism for gene regulation. While many cellular factors are known to regulate their binding, little is known on how cells can modulate their unbinding for regulation. Using nanometer-precision single-molecule tracking, we study the unbinding kinetics from DNA of two metal-sensing transcription regulators in living Escherichia coli cells. We find that they show unusual concentration-dependent unbinding kinetics from chromosomal recognition sites in both their apo and holo forms. Unexpectedly, their unbinding kinetics further varies with the extent of chromosome condensation, and more surprisingly, varies in opposite ways for their apo-repressor versus holo-activator forms. These findings suggest likely broadly relevant mechanisms for facile switching between transcription activation and deactivation in vivo and in coordinating transcription regulation of resistance genes with the cell cycle. Binding and unbinding of transcription regulators at operator sites regulates gene expression. By single-molecule tracking of metal-sensing regulators, here the authors show that the unbinding kinetics depends on regulator concentration and chromosome condensation, and varies with their metal-binding states.