Localization of intraflagellar transport protein IFT52 identifies basal body transitional fibers as the docking site for IFT particles
Localization of intraflagellar transport protein IFT52 identifies basal body transitional fibers as the docking site for IFT particles
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DOI：
10.1016/s0960-9822(01)00484-5
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发表时间：
2001-10-16
期刊：
影响因子：
9.2
通讯作者：
Rosenbaum, JL
中科院分区：
文献类型：
--
作者：
Deane, JA;Cole, DG;Rosenbaum, JL
鞭毛内转运（IFT）[1，2]是一种运动性，其中由至少17种多肽[3-5]组成的颗粒在鞭毛膜下移动[1，2]。这些IFT颗粒的顺行（向外）和逆行（向内）运动分别由FLA 10驱动蛋白-II [2，3]和细胞质动力蛋白DHC 1b [6-8]介导。影响IFT颗粒多肽[9]或马达的突变导致不能组装鞭毛[2，6-8，10-12]。IFT颗粒和移动它们的马达主要位于基体周围以及鞭毛中[3，7，13，14]。在这里，我们克隆的cDNA编码的IFT颗粒蛋白，IFFT 52，并显示免疫荧光，而一些IFFT 52是在鞭毛中，大多数是在两个马蹄形环周围的基体。免疫电子显微镜表明，IFFT 52与过渡纤维的外周相关，过渡纤维从基体的远端部分延伸到细胞膜，并划分鞭毛室的入口[15-18]。这种定位表明过渡纤维形成了注定要到达鞭毛的IFT颗粒的对接复合物。最后，无鞭毛突变体bld 1由于编码IFFT 52的基因中的缺失而完全缺乏IFFT 52 [19]。
Intraflagellar transport (IFT) [1, 2] is a motility in which particles composed of at least 17 polypeptides [3-5] move underneath the flagellar membrane [1, 2]. Anterograde (outward) and retrograde (inward) movements of these IFT particles are mediated by FLA10 kinesin-II [2, 3] and cytoplasmic dynein DHC1b [6-8], respectively. Mutations affecting IFT particle polypeptides [9] or motors result in the inability to assemble flagella [2, 6-8, 10-12]. IFT particles and the motors moving them are located principally around the basal bodies as well as in the flagella [3, 7, 13, 14]. Here, we clone the cDNA encoding one of the IFT particle proteins, IFT52, and show by immunofluorescence that while some IFT52 is in the flagella, the majority is found in two horseshoe-shaped rings around the basal bodies. Immunoelectron microscopy indicates that IFT52 is associated with the periphery of the transitional fibers, which extend from the distal portion of the basal body to the cell membrane and demarcate the entrance to the flagellar compartment [15-18]. This localization suggests that the transitional fibers form a docking complex for the IFT particles destined for the flagellum. Finally, the flagellaless mutant bld1 completely lacks IFT52 due to a deletion in the gene encoding IFT52 [19].