Autophosphorylation-induced self-assembly and STIL-dependent reinforcement underlie Plk4's ring-to-dot localization conversion around a human centriole.
Autophosphorylation-induced self-assembly and STIL-dependent reinforcement underlie Plk4's ring-to-dot localization conversion around a human centriole.
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自磷酸化诱导的自组装和 STIL 依赖性强化是 Plk4 在人类中心粒周围从环到点定位转换的基础。
DOI：
10.1080/15384101.2020.1843772
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Lee,KyungS
中科院分区：
文献类型：
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作者：
Park,Jung-Eun;Meng,Lingjun;Ryu,EunKyoung;Nagashima,Kunio;Baxa,Ulrich;Bang,JeongKyu;Lee,KyungS
Polo样激酶4（Plk 4）是中心粒生物发生的关键调节因子。研究表明，Plk 4经历了从围绕中心粒的环状图案到在原中心粒组装位点的点状形态的动态重定位，并且该事件对于诱导中心粒生物发生是中心粒生物发生的中心。然而，Plk 4驱动其突破性的环到点重新定位能力的详细机制在很大程度上仍然未知。在这里，我们发现Plk 4以自磷酸化依赖的方式自我启动这一过程，并且其下游靶标STIL对于该事件不是必需的。与mEOS融合的光转换Plk 4的时间依赖性分析显示，一部分环状态Plk 4获得的能力，大概是通过自磷酸化，徘徊在中心粒周围，最终产生点状态的形态。有趣的是，Plk 4 WT，而不是其无催化活性的突变体，显示出在人细胞或异源E的胞质溶胶中形成纳米级球形组装体的能力。大肠杆菌，证明其自磷酸化依赖的自组织能力。在生物化学水平，Plk 4-不像其N-末端βTrCP降解决定子基序-在其C-末端隐蔽polo-box内稳健地自磷酸化PC 3 SSTT基序，这是诱导其物理聚类的关键事件。此外，体内实验表明，虽然STIL是不需要Plk 4的初始环到点的转换，共表达STIL大大增强了Plk 4的能力，产生一个球形的冷凝物和招聘Sas 6，一个中心粒车轮结构的主要组成部分。我们建议，Plk 4的自磷酸化诱导的聚类是足以诱导其环到点的本地化转换，随后招募STIL加强这一过程中产生一个原中心粒组装体Plk 4依赖中心粒生物发生的关键。
Polo-like kinase 4 (Plk4) is a key regulator of centriole biogenesis. Studies have shown that Plk4 undergoes dynamic relocalization from a ring-like pattern around a centriole to a dot-like morphology at the procentriole assembly site and this event is central for inducing centriole biogenesis. However, the detailed mechanisms underlying Plk4’s capacity to drive its symmetry-breaking ring-to-dot relocalization remain largely unknown. Here, we showed that Plk4 self-initiates this process in an autophosphorylation–dependent manner and that STIL, its downstream target, is not required for this event. Time-dependent analyses with mEOS-fused photoconvertible Plk4 revealed that a portion of ring-state Plk4 acquires a capacity, presumably through autophosphorylation, to linger around a centriole, ultimately generating a dot-state morphology. Interestingly, Plk4 WT, but not its catalytically inactive mutant, showed the ability to form a nanoscale spherical assembly in the cytosol of human cells or heterologousE. coli, demonstrating its autophosphorylation-dependent self-organizing capacity. At the biochemical level, Plk4 – unlike its N-terminal βTrCP degron motif – robustly autophosphorylated the PC3 SSTT motif within its C-terminal cryptic polo-box, an event critical for inducing its physical clustering. Additionalin vivoexperiments showed that although STIL was not required for Plk4’s initial ring-to-dot conversion, coexpressed STIL greatly enhanced Plk4’s ability to generate a spherical condensate and recruit Sas6, a major component of the centriolar cartwheel structure. We propose that Plk4’s autophosphorylation-induced clustering is sufficient to induce its ring-to-dot localization conversion and that subsequently recruited STIL potentiates this process to generate a procentriole assembly body critical for Plk4-dependent centriole biogenesis.