Bug22p, a Conserved Centrosomal/Ciliary Protein Also Present in Higher Plants, Is Required for an Effective Ciliary Stroke in Paramecium
Bug22p, a Conserved Centrosomal/Ciliary Protein Also Present in Higher Plants, Is Required for an Effective Ciliary Stroke in Paramecium
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DOI：
10.1128/ec.00368-09
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发表时间：
2010-04-01
期刊：
影响因子：
--
通讯作者：
Koll, F.
中科院分区：
文献类型：
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作者：
Laligne, C.;Klotz, C.;Koll, F.
中心粒、纤毛和鞭毛是真核细胞祖先保守的细胞器。在草履虫纤毛蛋白的蛋白质组学中鉴定出的蛋白质中，我们重点关注一种蛋白质 Bug22p，该蛋白质之前已被纤毛和基体高通量研究检测到，但从未对其本身进行过分析。值得注意的是，这种蛋白质也存在于缺乏中心粒和纤毛的植物中。 Bug22p 序列比对揭示了区分具有中心粒/纤毛的物种与植物的共有位置。在草履虫中，抗体和绿色荧光蛋白 (GFP) 融合标记将 Bug22p 定位在基体和纤毛中，电子显微镜免疫标记将定位细化到基体的终板、过渡区和沿轴丝的斑点，优先在膜和微管之间。 Bug22p 的 RNA 干扰 (RNAi) 消耗导致游泳速度大幅下降，几天后细胞死亡。高速视频显微镜和 Bug22p 耗尽细胞的形态分析表明，该蛋白通过参与纤毛的笔划形状和刚性，在纤毛运动的效率中发挥重要作用。 RNAi 引起的细胞游动和生长缺陷可以通过表达人 Bug22p 来补充。这是第一个报道的纤毛虫中人类基因互补的案例。
Centrioles, cilia, and flagella are ancestral conserved organelles of eukaryotic cells. Among the proteins identified in the proteomics of ciliary proteins in Paramecium, we focus here on a protein, Bug22p, previously detected by cilia and basal-body high-throughput studies but never analyzed per se. Remarkably, this protein is also present in plants, which lack centrioles and cilia. Bug22p sequence alignments revealed consensus positions that distinguish species with centrioles/cilia from plants. In Paramecium, antibody and green fluorescent protein (GFP) fusion labeling localized Bug22p in basal bodies and cilia, and electron microscopy immunolabeling refined the localization to the terminal plate of the basal bodies, the transition zone, and spots along the axoneme, preferentially between the membrane and the microtubules. RNA interference (RNAi) depletion of Bug22p provoked a strong decrease in swimming speed, followed by cell death after a few days. High-speed video microscopy and morphological analysis of Bug22p-depleted cells showed that the protein plays an important role in the efficiency of ciliary movement by participating in the stroke shape and rigidity of cilia. The defects in cell swimming and growth provoked by RNAi can be complemented by expression of human Bug22p. This is the first reported case of complementation by a human gene in a ciliate.