To let go or not to let go: how ParA can impact the release of the chromosomal anchoring in Caulobacter crescentus.
To let go or not to let go: how ParA can impact the release of the chromosomal anchoring in Caulobacter crescentus.
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放手还是不放手：ParA 如何影响新月柄杆菌中染色体锚定的释放。
DOI：
10.1101/2023.04.12.536610
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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：
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作者：
Puentes-Rodriguez,StephanieG;Norcross,JD;Mera,PaolaE
染色体的维持对于细菌的生存至关重要。新月柄杆菌的染色体复制起始于一个着丝粒，分离延迟到附近的着丝粒样区域复制。我们对这一系列事件是如何调节的理解仍然有限。parS的分离涉及多个步骤，包括从锚定蛋白PopZ的极性释放，缓慢移动和快速ParA依赖性移动到相反的细胞极。在这项研究中，我们证明，帕拉的竞争吸引力从PopZ和DNA的分离parS是至关重要的。通过表达不能结合DNA的变异体ParA-R195 E，从而仅有利于ParA-PopZ之间的相互作用，干扰这种吸引平衡，导致细胞死亡。我们的数据显示，ParA-R195 E与PopZ的唯一相互作用阻碍了PopZ释放parS极性锚定的能力，导致具有多个parS位点的细胞固定在一个细胞极。我们发现，无法分离和隔离multipleparSloci从极点是专门依赖于帕拉和PopZ之间的相互作用。总的来说，我们的研究结果表明，染色体分离的初始步骤是高度调节的。
Chromosomal maintenance is vital for the survival of bacteria. InCaulobacter crescentus, chromosome replication initiates atoriand segregation is delayed until the nearby centromere-like regionparSis replicated. Our understanding of how this sequence of events is regulated remains limited. The segregation ofparShas been shown to involve multiple steps including polar release from anchoring protein PopZ, slow movement and fast ParA-dependent movement to the opposite cell pole. In this study, we demonstrate that ParA’s competing attractions from PopZ and from DNA are critical for segregation ofparS. Interfering with this balance of attractions—by expressing a variant ParA-R195E unable to bind DNA and thus favoring interactions exclusively between ParA-PopZ—results in cell death. Our data revealed that ParA-R195E’s sole interactions with PopZ obstruct PopZ’s ability to release the polar anchoring ofparS, resulting in cells with multipleparSloci fixed at one cell pole. We show that the inability to separate and segregate multipleparSloci from the pole is specifically dependent on the interaction between ParA and PopZ. Collectively, our results reveal that the initial steps in chromosome segregation are highly regulated.