Qi Feifei, Yin Shanshan, Yang Xiangrui, Ju Ning, Liu Bohan, Zhang Xing, Zhu Zixuan, Ji Li, Zhang Fuxin, Zhao Li, Wang Ruoxi, Liu Min, Zhang Liangran, Zhao Huijie, Zhou Jun, Gao Jinmin
Center for Cell Structure and Function, College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Shandong Normal University, Jinan, China.
State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, China.
EMBO Rep. 2025 May 23. doi: 10.1038/s44319-025-00485-7.
In most metazoans, centrosome elimination during oogenesis ensures accurate centriole inheritance in the zygote, yet the molecular mechanisms remain poorly understood. Here, we reveal a critical role for controlled SAS-6 phosphorylation in centrosome dynamics during oogenesis. Centrioles disassemble during late meiotic prophase, while the cartwheel protein SAS-6 exhibits dynamic behavior in early meiotic prophase. Purified SAS-6 undergoes phase separation in vitro, and overexpressed SAS-6 forms droplets in cells. Mass spectrometry and kinase assays reveal that SAS-6 is phosphorylated at its C-terminus in cells and in vivo, with CDK-1 identified as a direct kinase. This phosphorylation inhibits SAS-6 phase separation and weakens interactions between centriolar proteins. SAS-6 degradation confirms its role in centrosome stability, and CDK-1 activity is required for timely centriole disassembly. Phospho-mimetic and phospho-deficient mutants demonstrate that dynamic SAS-6 phosphorylation is essential for centrosome assembly and elimination. We propose that the disordered C-terminus of SAS-6 facilitates cartwheel stacking via multivalent weak interactions, promoting centriole stability. Phosphorylation disrupts these interactions, impairing centrosome duplication and promoting elimination during oogenesis.
在大多数后生动物中，卵子发生过程中的中心体消除确保了合子中中心粒的准确遗传，但其分子机制仍知之甚少。在此，我们揭示了在卵子发生过程中，可控的SAS-6磷酸化在中心体动态变化中起关键作用。中心粒在减数分裂前期后期解体，而车轮蛋白SAS-6在减数分裂前期早期表现出动态行为。纯化的SAS-6在体外发生相分离，过表达的SAS-6在细胞中形成液滴。质谱分析和激酶分析表明，SAS-6在细胞内和体内其C末端被磷酸化，其中CDK-1被鉴定为直接激酶。这种磷酸化抑制了SAS-6的相分离，并削弱了中心粒蛋白之间的相互作用。SAS-6的降解证实了其在中心体稳定性中的作用，而CDK-1活性是中心粒及时解体所必需的。磷酸模拟和磷酸缺陷突变体表明，动态的SAS-6磷酸化对于中心体的组装和消除至关重要。我们提出，SAS-6无序的C末端通过多价弱相互作用促进车轮堆叠，从而增强中心粒稳定性。磷酸化破坏了这些相互作用，损害了中心体复制，并在卵子发生过程中促进中心体消除。
