Pachinger Claudia, Dobbelaere Jeroen, Rumpf-Kienzl Cornelia, Raina Shiviya, Garcia-Baucells Júlia, Sarantseva Marina, Brauneis Andrea, Dammermann Alexander
Max Perutz Labs, Vienna Biocenter (VBC), University of Vienna , Vienna, Austria.
Vienna BioCenter PhD Program, Doctoral School of the University of Vienna and Medical University of Vienna , Vienna, Austria.
J Cell Biol. 2025 Aug 4;224(8). doi: 10.1083/jcb.202408042. Epub 2025 May 21.
Centriolar satellites are cytoplasmic particles found in the vicinity of centrosomes and cilia whose specific functional contribution has long been unclear. Here, we identify Combover as the Drosophila ortholog of the main scaffolding component of satellites, PCM1. Like PCM1, Combover localizes to cytoplasmic foci containing centrosomal proteins and its depletion or mutation results in centrosomal and ciliary phenotypes. Strikingly, however, the concentration of satellites near centrosomes and cilia is not a conserved feature, nor do Combover foci display directed movement. Proximity interaction analysis revealed not only centrosomal and ciliary proteins, but also RNA-binding proteins and proteins involved in quality control. Further work in Drosophila and vertebrate cells found satellites to be associated with centrosomal and ciliary mRNAs, as well as evidence for protein synthesis occurring directly at satellites. Given that PCM1 depletion does not affect overall protein levels, we propose that satellites instead promote the coordinate synthesis of centrosomal and ciliary proteins, thereby facilitating the formation of protein complexes.
中心粒卫星是在中心体和纤毛附近发现的细胞质颗粒,其具体功能贡献长期以来一直不清楚。在这里,我们鉴定出“梳状结构”是卫星主要支架成分PCM1在果蝇中的直系同源物。与PCM1一样,“梳状结构”定位于含有中心体蛋白的细胞质病灶,其缺失或突变会导致中心体和纤毛表型。然而,令人惊讶的是,中心体和纤毛附近卫星的聚集并不是一个保守特征,“梳状结构”病灶也没有显示出定向运动。邻近相互作用分析不仅揭示了中心体和纤毛蛋白,还揭示了RNA结合蛋白和参与质量控制的蛋白。在果蝇和脊椎动物细胞中的进一步研究发现,卫星与中心体和纤毛mRNA相关,也有证据表明蛋白质合成直接发生在卫星上。鉴于PCM1的缺失不影响整体蛋白质水平,我们提出卫星反而促进中心体和纤毛蛋白的协同合成,从而促进蛋白质复合物的形成。