RNA polymerase II depletion from the inactive X chromosome territory is not mediated by physical compartmentalization.
RNA polymerase II depletion from the inactive X chromosome territory is not mediated by physical compartmentalization.
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DOI：
10.1038/s41594-023-01008-5
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发表时间：
2023-08
影响因子：
16.8
通讯作者：
Heard, Edith
中科院分区：
文献类型：
--
作者：
Collombet, Samuel;Rall, Isabell;Dugast-Darzacq, Claire;Heckert, Alec;Halavatyi, Aliaksandr;Le Saux, Agnes;Dailey, Gina;Darzacq, Xavier;Heard, Edith
亚核区室化被认为在基因调控中起重要作用，它通过在不同的物理和生化环境中分离基因组的活性和非活性部分。在X染色体失活（XCI）期间，非编码Xist RNA包覆X染色体，触发基因沉默并形成异染色质的致密体，转录机制似乎被排除在外。相分离已被提出参与XCI，并可能解释排斥的转录机制，防止其扩散到XIST包被的领土。在这里，使用定量荧光显微镜和单粒子跟踪，我们表明，RNA聚合酶II（RNAPII）自由访问Xist领土在启动XCI。相反，RNAPII的明显消耗是由于其染色质稳定结合部分的损失。这些研究结果表明，最初排除RNAPII从非活性X反映了积极转录RNAPII的情况下，而不是一个假定的物理区室化的非活性X异染色质结构域的后果。作者表明，RNAPII从失活X染色体区域的明显消耗不是由于生物物理区室化效应，而是由于染色质上RNAPII结合部分的损失。
Subnuclear compartmentalization has been proposed to play an important role in gene regulation by segregating active and inactive parts of the genome in distinct physical and biochemical environments. During X chromosome inactivation (XCI), the noncoding Xist RNA coats the X chromosome, triggers gene silencing and forms a dense body of heterochromatin from which the transcription machinery appears to be excluded. Phase separation has been proposed to be involved in XCI, and might explain the exclusion of the transcription machinery by preventing its diffusion into the Xist-coated territory. Here, using quantitative fluorescence microscopy and single-particle tracking, we show that RNA polymerase II (RNAPII) freely accesses the Xist territory during the initiation of XCI. Instead, the apparent depletion of RNAPII is due to the loss of its chromatin stably bound fraction. These findings indicate that initial exclusion of RNAPII from the inactive X reflects the absence of actively transcribing RNAPII, rather than a consequence of putative physical compartmentalization of the inactive X heterochromatin domain. The authors show that the apparent depletion of RNAPII from the inactive X chromosome territory is not due to a biophysical compartmentalization effect, but rather due to the loss of RNAPII bound fraction on chromatin.
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DOI：
10.1103/physreve.91.062716
发表时间：
2015-06
期刊：
Physical review. E, Statistical, nonlinear, and soft matter physics
影响因子：
--
作者：
Backlund MP;Joyner R;Moerner WE
通讯作者：
Moerner WE
影响因子：
7.7
作者：
Heckert, Alec;Dahal, Liza;Tijan, Robert;Darzacq, Xavier
通讯作者：
Darzacq, Xavier
预测聚合物建模揭示了染色体构象和转录中的波动耦合。
影响因子：
64.5
作者：
Giorgetti L;Galupa R;Nora EP;Piolot T;Lam F;Dekker J;Tiana G;Heard E
通讯作者：
Heard E
影响因子：
16.8
作者：
Jachowicz JW;Strehle M;Banerjee AK;Blanco MR;Thai J;Guttman M
通讯作者：
Guttman M
影响因子：
16
作者：
Chong, Shasha;Graham, Thomas G. W.;Tjian, Robert
通讯作者：
Tjian, Robert