Conkar Deniz, Culfa Efraim, Odabasi Ezgi, Rauniyar Navin, Yates John R, Firat-Karalar Elif N
Department of Molecular Biology and Genetics, Koç University, Istanbul 34450, Turkey.
Department of Chemical Biology, The Scripps Research Institute, 10550 N. Torrey Pines Rd., La Jolla, CA 92037, USA.
J Cell Sci. 2017 Apr 15;130(8):1450-1462. doi: 10.1242/jcs.196832. Epub 2017 Feb 24.
Centriolar satellites are membrane-less structures that localize and move around the centrosome and cilium complex in a microtubule-dependent manner. They play important roles in centrosome- and cilium-related processes, including protein trafficking to the centrosome and cilium complex, and ciliogenesis, and they are implicated in ciliopathies. Despite the important regulatory roles of centriolar satellites in the assembly and function of the centrosome and cilium complex, the molecular mechanisms of their functions remain poorly understood. To dissect the mechanism for their regulatory roles during ciliogenesis, we performed an analysis to determine the proteins that localize in close proximity to the satellite protein CEP72, among which was the retinal degeneration gene product CCDC66. We identified CCDC66 as a microtubule-associated protein that dynamically localizes to the centrosome, centriolar satellites and the primary cilium throughout the cell cycle. Like the BBSome component BBS4, CCDC66 distributes between satellites and the primary cilium during ciliogenesis. CCDC66 has extensive proximity interactions with centrosome and centriolar satellite proteins, and co-immunoprecipitation experiments revealed interactions between CCDC66, CEP290 and PCM1. Ciliogenesis, ciliary recruitment of BBS4 and centriolar satellite organization are impaired in cells depleted for CCDC66. Taken together, our findings identify CCDC66 as a targeting factor for centrosome and cilium proteins.
中心粒卫星是无膜结构，以微管依赖的方式定位于中心体和纤毛复合体周围并在其周围移动。它们在与中心体和纤毛相关的过程中发挥重要作用，包括蛋白质向中心体和纤毛复合体的运输以及纤毛发生，并且与纤毛病有关。尽管中心粒卫星在中心体和纤毛复合体的组装和功能中具有重要的调节作用，但其功能的分子机制仍知之甚少。为了剖析它们在纤毛发生过程中的调节作用机制，我们进行了一项分析，以确定定位于卫星蛋白CEP72附近的蛋白质，其中包括视网膜变性基因产物CCDC66。我们将CCDC66鉴定为一种微管相关蛋白，它在整个细胞周期中动态定位于中心体、中心粒卫星和初级纤毛。与BBSome组分BBS4一样，CCDC66在纤毛发生过程中分布于卫星和初级纤毛之间。CCDC66与中心体和中心粒卫星蛋白有广泛的邻近相互作用，免疫共沉淀实验揭示了CCDC66、CEP290和PCM1之间的相互作用。在耗尽CCDC66的细胞中，纤毛发生、BBS4的纤毛募集和中心粒卫星组织受损。综上所述，我们的研究结果确定CCDC66是中心体和纤毛蛋白的靶向因子。
