Pfister Jason A, Agostini Lorenzo, Bournonville Lorène, Perrier Aurélien, Sankaralingam Prabhu, Bell Zachary G, Hamel Virginie, Guichard Paul, Biertümpfel Christian, Mizuno Naoko, O'Connell Kevin F
Laboratory of Biochemistry and Genetics, National Institutes of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, USA.
Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD, USA.
Nat Commun. 2025 Jun 5;16(1):5220. doi: 10.1038/s41467-025-59939-0.
Centrioles play key roles in mitotic spindle assembly. Once assembled, centrioles exhibit long-term stability, but how stability is achieved and how it is regulated are not completely understood. In this study we show that SSNA-1, the Caenorhabditis elegans ortholog of Sjogren's Syndrome Nuclear Antigen 1, is a constituent of centrioles and centriole satellite-like structures. A deletion of ssna-1 results in the formation of extra centrioles. We show that SSNA-1 genetically interacts with the centriole stability factor SAS-1 and is required post assembly for centriole structural integrity. In SSNA-1's absence, centrioles assemble but fracture leading to extra spindle poles. However, if the efficiency of cartwheel assembly is reduced, the absence of SSNA-1 results in daughter centriole loss and monopolar spindles, indicating that the cartwheel and SSNA-1 cooperate to stabilize centrioles during assembly. Our work thus shows that SSNA-1 contributes to centriole stability during and after assembly, thereby ensuring proper centriole number.
中心粒在有丝分裂纺锤体组装中发挥关键作用。一旦组装完成，中心粒表现出长期稳定性，但稳定性是如何实现的以及如何调控尚未完全明了。在本研究中，我们发现秀丽隐杆线虫中干燥综合征核抗原1的直系同源物SSNA-1是中心粒和中心粒卫星样结构的一个组成部分。缺失ssna-1会导致额外中心粒的形成。我们表明，SSNA-1与中心粒稳定性因子SAS-1发生遗传相互作用，并且在组装后对于中心粒结构完整性是必需的。在没有SSNA-1的情况下，中心粒能够组装但会断裂，导致额外的纺锤体极。然而，如果轮盘组装效率降低，缺少SSNA-1会导致子中心粒丢失和单极纺锤体，这表明轮盘和SSNA-1在组装过程中协同作用以稳定中心粒。因此，我们的工作表明SSNA-1在组装期间和之后有助于中心粒稳定性，从而确保中心粒数量合适。
