Abstract While many bacteria divide by symmetric binary fission, some alphaproteobacteria have strikingly asymmetric cell cycles, producing offspring that differs significantly in their morphology and reproductive state. To establish this asymmetry, these species employ a complex cell cycle regulatory pathway based on two-component signaling cascades. At the center of this network is the essential DNA-binding response regulator CtrA, which acts as a transcription factor controlling numerous genes with cell cycle-relevant functions as well as a regulator of chromosome replication. The DNA-binding activity of CtrA is controlled at the level of both protein phosphorylation and stability, dependent on an intricate network of regulatory proteins, whose function is tightly coordinated in time and space. CtrA is differentially activated in the two (developing) offspring, thereby establishing distinct transcriptional programs that ultimately determine their distinct cell fates. Phase-separated polar microdomains of changing composition sequester proteins involved in the (in-)activation and degradation of CtrA specifically at each pole. In this review, we summarize the current knowledge of the CtrA pathway and discuss how it has evolved to regulate the cell cycle of morphologically distinct alphaproteobacteria.

中文翻译：

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在不断变化的环境中产生不对称性：二态性 alphaproteobacteria 中的细胞周期调节

摘要 虽然许多细菌通过对称二元裂变进行分裂，但一些 alphaproteobacteria 具有惊人的不对称细胞周期，产生的后代在形态和生殖状态上存在显着差异。为了建立这种不对称性，这些物种采用基于双组分信号级联的复杂细胞周期调节途径。该网络的中心是必不可少的 DNA 结合反应调节器 CtrA，它充当转录因子，控制许多具有细胞周期相关功能的基因以及染色体复制的调节器。CtrA 的 DNA 结合活性受蛋白质磷酸化和稳定性水平的控制，取决于复杂的调节蛋白网络，其功能在时间和空间上紧密协调。CtrA 在两个（发育中的）后代中被不同地激活，从而建立不同的转录程序，最终决定它们不同的细胞命运。改变组成的相分离极性微区隔离参与 CtrA 的（in-）激活和降解的蛋白质，特别是在每个极点。在这篇综述中，我们总结了 CtrA 通路的当前知识，并讨论了它如何进化以调节形态不同的 alphaproteobacteria 的细胞周期。