TipN's involvement with centromere segregation in Caulobacter crescentus.
TipN's involvement with centromere segregation in Caulobacter crescentus.
复制标题
TipN 参与新月柄杆菌着丝粒分离。
DOI：
10.1101/2023.12.20.572679
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Mera,PaolaE
中科院分区：
文献类型：
--
作者：
Letzkus,Morgan;Trela,Corey;Mera,PaolaE
细菌在整个生命周期中保持染色体完整性的能力对其生存至关重要。在新月柄杆菌中，极性因子 TipN 被认为与分配系统 ParABS 相关。然而，tipN 被敲除的细胞表现出微妙的 parS 分离缺陷。我们假设 TipN 在 parS 分离中的作用被与 ParABS 无关的其他力量所掩盖。为了检验我们的假设，我们消除了其中一种力量——染色体复制——并分析了 TipN 与 ParA 的作用。我们首先证明，在没有染色体复制的情况下，ParA 保留了将着丝粒区域 parS 从有柄极运输到相反极的能力。我们的数据显示，在没有染色体复制的情况下，TipN 对于 ParA 运输 parS 的能力至关重要。此外，我们还确定了复制起始子 DnaA 和 TipN 之间的潜在联系。尽管 TipN 对于生存能力不是必需的，但当 DnaA 水平的调节发生改变时，tipN 敲除细胞就会丧失生存能力。我们的数据表明，tipN 敲除细胞的 DnaA 依赖性易感性与 parS 分离有关。总的来说，这项工作提供了对细菌染色体复制和分离协调所涉及的复杂调控的见解。
Bacteria’s ability to maintain chromosomal integrity throughout their life cycle is crucial for their survival. In Caulobacter crescentus, the polar factor TipN has been proposed to be involved with the partitioning system ParABS. However, cells with tipN knocked out display subtle parS segregation defects. We hypothesized that TipN’s role with parS segregation is obscured by other forces that are ParABS-independent. To test our hypothesis, we removed one of those forces – chromosome replication – and analyzed the role of TipN with ParA. We first demonstrate that ParA retains its ability to transport the centromeric region parS from the stalked pole to the opposite pole in the absence of chromosome replication. Our data revealed that in the absence of chromosome replication, TipN becomes essential for ParA’s ability to transport parS. Furthermore, we identify a potential connection between the replication initiator DnaA and TipN. Although TipN is not essential for viability, tipN knockout cells lose viability when the regulation of DnaA levels is altered. Our data suggest that the DnaA-dependent susceptibility of tipN knockout cells is connected to parS segregation. Collectively, this work provides insights into the complex regulation involved in the coordination of chromosome replication and segregation in bacteria.