Transcription shapes DNA replication initiation to preserve genome integrity.
Transcription shapes DNA replication initiation to preserve genome integrity.
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转录塑造 DNA 复制起始以保持基因组完整性
DOI：
10.1186/s13059-021-02390-3
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发表时间：
2021-06-09
期刊：
影响因子：
12.3
通讯作者：
Hu J
中科院分区：
文献类型：
--
作者：
Liu Y;Ai C;Gan T;Wu J;Jiang Y;Liu X;Lu R;Gao N;Li Q;Ji X;Hu J
在哺乳动物细胞中，DNA复制发生在活跃转录的染色质区室中，这就提出了早期DNA复制如何与转录协调以避免碰撞和DNA损伤的直接问题。我们开发了一种高通量核苷类似物结合测序方法，并在小鼠和人类细胞中鉴定了数千个早期复制起始区。鉴定的早期复制起始区落在开放的染色质室中，并且与转录伸长相互排斥。值得注意的是，早期复制起始区主要位于与转录区相邻的非转录区。在机制上，我们发现RNA聚合酶II主动重新分配染色质结合的迷你染色体维持复合体（MCM），而不是起源识别复合体（ORC），以主动限制转录区外的早期DNA复制起始。为了支持这一发现，我们检测到转录区域明显的MCM积累和DNA复制起始，这是由于核酸酶死亡的Cas9锚定在转录基因上，这阻碍了RNA聚合酶II。最后，我们发现通过转录的早期DNA复制起始的编排有效地防止了严重的DNA损伤。结论rna聚合酶II可重新分配MCM复合物，而非ORC，从而阻止转录区域内DNA早期复制的启动。这种RNA聚合酶ii驱动的MCM重分布在空间上分离了转录和早期DNA复制事件，避免了转录-复制起始冲突，从而为保持基因组稳定性提供了关键的调控机制。
BackgroundEarly DNA replication occurs within actively transcribed chromatin compartments in mammalian cells, raising the immediate question of how early DNA replication coordinates with transcription to avoid collisions and DNA damage.ResultsWe develop a high-throughput nucleoside analog incorporation sequencing assay and identify thousands of early replication initiation zones in both mouse and human cells. The identified early replication initiation zones fall in open chromatin compartments and are mutually exclusive with transcription elongation. Of note, early replication initiation zones are mainly located in non-transcribed regions adjacent to transcribed regions. Mechanistically, we find that RNA polymerase II actively redistributes the chromatin-bound mini-chromosome maintenance complex (MCM), but not the origin recognition complex (ORC), to actively restrict early DNA replication initiation outside of transcribed regions. In support of this finding, we detect apparent MCM accumulation and DNA replication initiation in transcribed regions due to anchoring of nuclease-dead Cas9 at transcribed genes, which stalls RNA polymerase II. Finally, we find that the orchestration of early DNA replication initiation by transcription efficiently prevents gross DNA damage.ConclusionRNA polymerase II redistributes MCM complexes, but not the ORC, to prevent early DNA replication from initiating within transcribed regions. This RNA polymerase II-driven MCM redistribution spatially separates transcription and early DNA replication events and avoids the transcription-replication initiation collision, thereby providing a critical regulatory mechanism to preserve genome stability.
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影响因子：
3.3
作者：
Bell SP;Labib K
通讯作者：
Labib K
影响因子：
64.5
作者：
Barlow JH;Faryabi RB;Callén E;Wong N;Malhowski A;Chen HT;Gutierrez-Cruz G;Sun HW;McKinnon P;Wright G;Casellas R;Robbiani DF;Staudt L;Fernandez-Capetillo O;Nussenzweig A
通讯作者：
Nussenzweig A
影响因子：
3.7
作者：
Chen, Ping;Liu, Zhongfa;Liu, Shujun;Xie, Zhiliang;Aimiuwu, Josephine;Pang, Jiuxia;Klisovic, Rebecca;Blum, William;Grever, Michael R.;Marcucci, Guido;Chan, Kenneth K.
通讯作者：
Chan, Kenneth K.
影响因子：
7
作者：
Cayrou, Christelle;Coulombe, Philippe;Mechali, Marcel
通讯作者：
Mechali, Marcel
DOI：
10.1073/pnas.0911500106
发表时间：
2009-12-01
影响因子：
11.1
作者：
Evrin, Cecile;Clarke, Pippa;Speck, Christian
通讯作者：
Speck, Christian