Department of Molecular Cellular and Developmental Biology, Yale University, New Haven, CT 06520, USA.
J Cell Sci. 2013 Nov 1;126(Pt 21):5018-29. doi: 10.1242/jcs.133439. Epub 2013 Aug 22.
The ciliary tip has been implicated in ciliary assembly and disassembly, and signaling, yet information on its protein composition is limited. Using comparative, quantitative proteomics based on the fact that tip proteins will be approximately twice as concentrated in half-length compared with full-length flagella, we have identified FAP256 as a tip protein in Chlamydomonas. FAP256 localizes to the tips of both central pair and outer doublet microtubules (MTs) and it remains at the tip during flagellar assembly and disassembly. Similarly, its vertebrate counterpart, CEP104, localizes on the distal ends of both centrioles of nondividing cells until the mother centriole forms a cilium and then localizes at the tip of the elongating cilium. A null mutant of FAP256 in Chlamydomonas and RNAi in vertebrate cells showed that FAP256/CEP104 is required for ciliogenesis in a high percentage of cells. In those cells that could form cilia, there were structural deformities at the ciliary tips.
纤毛顶端与纤毛的组装和拆卸以及信号转导有关，但有关其蛋白质组成的信息有限。利用比较定量蛋白质组学方法，基于顶端蛋白在半长纤毛中的浓度约为全长纤毛中的两倍的事实，我们鉴定出 FAP256 是衣藻中的一个纤毛顶端蛋白。FAP256 定位于中心对和外二联体微管（MT）的顶端，在纤毛组装和拆卸过程中它都位于顶端。类似地，其脊椎动物对应物 CEP104 定位于非分裂细胞的两个中心粒的远端，直到母中心粒形成纤毛，然后定位于正在伸长的纤毛的顶端。衣藻中的 FAP256 缺失突变体和脊椎动物细胞中的 RNAi 表明，FAP256/CEP104 是细胞中纤毛发生所必需的，在很大比例的细胞中都需要它。在那些能够形成纤毛的细胞中，纤毛顶端存在结构缺陷。
