Basal bodies (BBs) are macromolecular complexes required for the formation and cortical positioning of cilia. Both BB assembly and DNA replication are tightly coordinated with the cell cycle to ensure their accurate segregation and propagation to daughter cells, but the mechanisms ensuring coordination are unclear. The Tetrahymena Sas4/CPAP protein is enriched at assembling BBs, localizing to the core BB structure and to the base of BB-appendage microtubules and striated fiber. Sas4 is necessary for BB assembly and cortical microtubule organization, and Sas4 loss disrupts cell division furrow positioning and DNA segregation. The Hippo signaling pathway is known to regulate cell division furrow position, and Hippo molecules localize to BBs and BB-appendages. We find that Sas4 loss disrupts localization of the Hippo activator, Mob1, suggesting that Sas4 mediates Hippo activity by promoting scaffolds for Mob1 localization to the cell cortex. Thus, Sas4 links BBs with an ancient signaling pathway known to promote the accurate and symmetric segregation of the genome.

中文翻译：

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Sas4 通过 Hippo 信号传导将基底体与细胞分裂联系起来

基底体（BB）是纤毛形成和皮质定位所需的大分子复合物。BB组装和DNA复制都与细胞周期紧密协调，以确保它们准确分离并传播到子细胞，但确保协调的机制尚不清楚。四膜虫 Sas4/CPAP 蛋白在 BB 组装过程中富集，定位于核心 BB 结构以及 BB 附属物微管和条纹纤维的基部。Sas4 对于 BB 组装和皮质微管组织是必需的，Sas4 丢失会破坏细胞分裂沟定位和 DNA 分离。已知 Hippo 信号通路可调节细胞分裂沟位置，Hippo 分子定位于 BB 和 BB 附属物。我们发现 Sas4 的丢失破坏了 Hippo 激活剂 Mob1 的定位，这表明 Sas4 通过促进 Mob1 定位到细胞皮层的支架来介导 Hippo 活性。因此，Sas4 将 BB 与一条古老的信号通路连接起来，该通路已知可促进基因组的准确和对称分离。