Centriole splitting caused by loss of the centrosomal linker protein C-NAP1 reduces centriolar satellite density and impedes centrosome amplification.
Centriole splitting caused by loss of the centrosomal linker protein C-NAP1 reduces centriolar satellite density and impedes centrosome amplification.
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DOI：
10.1091/mbc.e16-05-0325
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发表时间：
2017-03-15
影响因子：
3.3
通讯作者：
Morrison CG
中科院分区：
文献类型：
--
作者：
Flanagan AM;Stavenschi E;Basavaraju S;Gaboriau D;Hoey DA;Morrison CG
敲除中心粒连接子C-NAP 1增加了中心粒分离和分散的中心粒卫星。初级纤毛形成正常，即使纤毛根被错误定位，和mechanosensory纤毛信号是完整的。DNA损伤后中心体扩增水平的降低表明中心粒邻近的重要性。中心体的复制是一个严格调控的过程。异常的中心体数量会损害细胞分裂，并导致细胞迁移方式的改变。重复的中心体通过蛋白质连接体连接在一起，该蛋白质连接体是由C-NAP 1锚定到中心粒的根杆丝组成的。当有丝分裂开始时，该接头以NEK 2A激酶依赖性方式被去除。为了探索C-NAP 1在调节中心体活动中的活性，我们使用基因组编辑来消除它。C-NAP 1无效细胞是可行的，并且具有过早中心粒分离的频率增加，伴随着中心粒卫星密度降低，C-NAP 1的重新表达挽救了两种表型。我们发现，初级纤毛，一个信号结构，来自停靠在细胞膜上的母亲中心粒，是完整的C-NAP 1的情况下，虽然纤毛根的组件异常本地化远离纤毛的基础。C-NAP 1缺陷的细胞能够通过纤毛的信号，确定流体流动诱导的剪切应力和刺猬途径的组件的重新定位后的基因表达分析。中心体扩增诱导的DNA损伤或PLK 4或CDK 2过表达显着减少C-NAP 1的情况下。我们的结论是，中心粒分裂减少了关键中心粒前体的局部密度，以阻止过度复制。
Knockout of the centriolar linker C-NAP1 increased centriole separation and dispersed centriolar satellites. Primary cilia formed normally, even though the ciliary rootlet was mislocalized, and mechanosensory ciliary signaling was intact. Reduced levels of centrosome amplification after DNA damage indicate the importance of centriole proximity. Duplication of the centrosomes is a tightly regulated process. Abnormal centrosome numbers can impair cell division and cause changes in how cells migrate. Duplicated centrosomes are held together by a proteinaceous linker made up of rootletin filaments anchored to the centrioles by C-NAP1. This linker is removed in a NEK2A kinase-dependent manner as mitosis begins. To explore C-NAP1 activities in regulating centrosome activities, we used genome editing to ablate it. C-NAP1–null cells were viable and had an increased frequency of premature centriole separation, accompanied by reduced density of the centriolar satellites, with reexpression of C-NAP1 rescuing both phenotypes. We found that the primary cilium, a signaling structure that arises from the mother centriole docked to the cell membrane, was intact in the absence of C-NAP1, although components of the ciliary rootlet were aberrantly localized away from the base of the cilium. C-NAP1–deficient cells were capable of signaling through the cilium, as determined by gene expression analysis after fluid flow–induced shear stress and the relocalization of components of the Hedgehog pathway. Centrosome amplification induced by DNA damage or by PLK4 or CDK2 overexpression was markedly reduced in the absence of C-NAP1. We conclude that centriole splitting reduces the local density of key centriolar precursors to impede overduplication.