Konno Alu, Shiba Kogiku, Cai Chunhua, Inaba Kazuo
Shimoda Marine Research Center, University of Tsukuba, Shimoda 5-10-1, Shizuoka 415-0025, Japan.
PLoS One. 2015 May 11;10(5):e0126005. doi: 10.1371/journal.pone.0126005. eCollection 2015.
Eukaryotic cilia and flagella have highly conserved 9 + 2 structures. They are functionally diverged to play cell-type-specific roles even in a multicellular organism. Although their structural components are therefore believed to be common, few studies have investigated the molecular diversity of the protein components of the cilia and flagella in a single organism. Here we carried out a proteomic analysis and compared protein components between branchial cilia and sperm flagella in a marine invertebrate chordate, Ciona intestinalis. Distinct feature of protein recruitment in branchial cilia and sperm flagella has been clarified; (1) Isoforms of α- and β-tubulins as well as those of actins are distinctly used in branchial cilia or sperm flagella. (2) Structural components, such as dynein docking complex, tektins and an outer dense fiber protein, are used differently by the cilia and flagella. (3) Sperm flagella are specialized for the cAMP- and Ca2+-dependent regulation of outer arm dynein and for energy metabolism by glycolytic enzymes. Our present study clearly demonstrates that flagellar or ciliary proteins are properly recruited according to their function and stability, despite their apparent structural resemblance and conservation.
真核生物的纤毛和鞭毛具有高度保守的9 + 2结构。即使在多细胞生物中，它们在功能上也有所分化，发挥着细胞类型特异性的作用。因此，尽管人们认为它们的结构成分是相同的，但很少有研究调查单个生物体中纤毛和鞭毛蛋白质成分的分子多样性。在这里，我们进行了蛋白质组学分析，并比较了海洋无脊椎动物脊索动物海鞘鳃纤毛和精子鞭毛之间的蛋白质成分。鳃纤毛和精子鞭毛中蛋白质募集的不同特征已经明确；（1）α-和β-微管蛋白的异构体以及肌动蛋白的异构体在鳃纤毛或精子鞭毛中被不同地使用。（2）动力蛋白对接复合体、微管轴丝蛋白和外致密纤维蛋白等结构成分在纤毛和鞭毛中的使用方式不同。（3）精子鞭毛专门用于对外侧臂动力蛋白进行cAMP和Ca2+依赖性调节以及通过糖酵解酶进行能量代谢。我们目前的研究清楚地表明，尽管鞭毛或纤毛蛋白在结构上明显相似且保守，但它们会根据其功能和稳定性被适当地募集。
