Centriolar satellites are dynamic, membraneless granules composed of over 200 proteins. They store, modify, and traffic centrosome and primary cilium proteins, and help to regulate both the biogenesis and some functions of centrosomes and cilium. In most cell types, satellites cluster around the perinuclear centrosome, but their integrity and cellular distribution are dynamically remodeled in response to different stimuli, such as cell cycle cues. Dissecting the specific and temporal functions and mechanisms of satellites and how these are influenced by their cellular positioning and dynamics has been challenging using genetic approaches, particularly in ciliated and proliferating cells. To address this, we developed a chemical-based trafficking assay to rapidly and efficiently redistribute satellites to either the cell periphery or center, and fuse them into stable clusters in a temporally controlled way. Induced satellite clustering at either the periphery or center resulted in antagonistic changes in the pericentrosomal levels of a subset of proteins, revealing a direct and selective role for their positioning in protein targeting and sequestration. Systematic analysis of the interactome of peripheral satellite clusters revealed enrichment of proteins implicated in cilium biogenesis and mitosis. Importantly, induction of peripheral satellite targeting in ciliated cells revealed a function for satellites not just for efficient cilium assembly but also in the maintenance of steady-state cilia and in cilia disassembly by regulating the structural integrity of the ciliary axoneme. Finally, perturbing satellite distribution and dynamics inhibited their mitotic dissolution, and mitotic progression was perturbed only in cells with centrosomal satellite clustering. Collectively, our results for the first time showed a direct link between satellite functions and their pericentrosomal clustering, suggested new mechanisms underlying satellite functions during cilium assembly, and provided a new tool for probing temporal satellite functions in different contexts

中心卫星是由200多种蛋白质组成的动态无膜颗粒。它们存储，修饰和运输中心体和初级纤毛蛋白，并帮助调节中心体和纤毛的生物发生和某些功能。在大多数细胞类型中，卫星聚集在核周中心体周围，但是它们的完整性和细胞分布会根据不同的刺激（例如细胞周期提示）而动态重塑。使用遗传方法，尤其是在纤毛和增生细胞中，剖析卫星的特定和暂时的功能和机制以及它们如何受到其细胞定位和动力学的影响一直是一个挑战。为了解决这个问题，我们开发了一种基于化学物质的贩运测定法，可以快速有效地将卫星重新分配到细胞周围或中央，并以时间控制的方式将它们融合成稳定的簇。在外围或中心的诱导卫星簇集导致蛋白质亚群的中央体水平的拮抗变化，揭示了它们在蛋白质靶向和螯合中的定位的直接和选择性作用。对外围卫星簇的相互作用组的系统分析表明，与纤毛发生和有丝分裂有关的蛋白质富集。重要的是，在纤毛细胞中诱导外周卫星靶向揭示了卫星的功能，不仅用于有效的纤毛组装，而且还通过调节纤毛轴突的结构完整性维持纤毛的稳态和纤毛的分解。最后，扰动卫星分布和动力学抑制了它们的有丝分裂溶解，并且有丝分裂的进展仅在具有中心体卫星簇的细胞中受到干扰。总的来说，我们的结果首次显示了卫星功能与其中心周围簇之间的直接联系，在纤毛组装过程中提出了卫星功能背后的新机制，并提供了一种在不同情况下探测时间卫星功能的新工具