Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK.
Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
J Cell Sci. 2022 Jul 15;135(14). doi: 10.1242/jcs.260015. Epub 2022 Jul 20.
Centrioles are composed of a central cartwheel tethered to nine-fold symmetric microtubule (MT) blades. The centriole cartwheel and MTs are thought to grow from opposite ends of these organelles, so it is unclear how they coordinate their assembly. We previously showed that in Drosophila embryos an oscillation of Polo-like kinase 4 (Plk4) helps to initiate and time the growth of the cartwheel at the proximal end. Here, in the same model, we show that CP110 and Cep97 form a complex close to the distal-end of the centriole MTs whose levels rise and fall as the new centriole MTs grow, in a manner that appears to be entrained by the core cyclin-dependent kinase (Cdk)-Cyclin oscillator that drives the nuclear divisions in these embryos. These CP110 and Cep97 dynamics, however, do not appear to time the period of centriole MT growth directly. Instead, we find that changing the levels of CP110 and Cep97 appears to alter the Plk4 oscillation and the growth of the cartwheel at the proximal end. These findings reveal an unexpected potential crosstalk between factors normally concentrated at opposite ends of the growing centrioles, which might help to coordinate centriole growth. This article has an associated First Person interview with the first authors of the paper.
中心粒由中央轮辐与九倍对称的微管（MT）叶片组成。中心粒轮辐和 MT 被认为是从这些细胞器的相对两端生长的，因此不清楚它们如何协调其组装。我们之前曾表明，在果蝇胚胎中，Polo 样激酶 4（Plk4）的振荡有助于启动和定时近端中心粒轮辐的生长。在这里，在相同的模型中，我们表明 CP110 和 Cep97 形成一个靠近中心粒 MT 远端的复合物，其水平随着新的中心粒 MT 的生长而上升和下降，这种方式似乎被驱动这些胚胎核分裂的核心细胞周期蛋白依赖性激酶（Cdk）-细胞周期蛋白振荡器所牵制。然而，这些 CP110 和 Cep97 的动态似乎并没有直接定时中心粒 MT 生长的周期。相反，我们发现改变 CP110 和 Cep97 的水平似乎会改变近端轮辐的 Plk4 振荡和生长。这些发现揭示了通常集中在生长中心粒相对两端的因素之间出乎意料的潜在串扰，这可能有助于协调中心粒的生长。本文有一篇与该论文第一作者的相关第一人称采访。
