Chlamydomonas DYX1C1/PF23 is essential for axonemal assembly and proper morphology of inner dynein arms.
Chlamydomonas DYX1C1/PF23 is essential for axonemal assembly and proper morphology of inner dynein arms.
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DOI：
10.1371/journal.pgen.1006996
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发表时间：
2017-09
期刊：
影响因子：
4.5
通讯作者：
Dutcher SK
中科院分区：
文献类型：
--
作者：
Yamamoto R;Obbineni JM;Alford LM;Ide T;Owa M;Hwang J;Kon T;Inaba K;James N;King SM;Ishikawa T;Sale WS;Dutcher SK
纤毛动力蛋白的细胞质组装，一个被称为预组装的过程，需要许多非动力蛋白，但这些蛋白的身份和功能尚未完全阐明。在这里，我们发现经典的衣藻运动突变体pf23在衣藻DYX1C1同源基因中存在缺陷。pf23突变体DYX1C1基因缺失494 bp，在细胞质中表达较短的DYX1C1蛋白。结构分析，使用冷冻- et，揭示pf23轴体缺乏大部分内部动力蛋白臂。光谱计数证实，DYX1C1对于大多数纤毛内动力蛋白臂（IDA）和一小部分外动力蛋白臂（ODA）的组装是必不可少的。DYX1C1的c端截断显示这些纤毛IDAs的一个子集减少。细胞质提取物的蔗糖梯度表明，与野生型相比，预组装的纤毛动力蛋白减少了，这表明在动力蛋白复合物的稳定性中起重要作用。PF23/DYX1C1的作用尚不清楚，但我们认为DYX1C1可以为大分子组装提供支架。大多数动物细胞都有类似天线的细胞器，叫做“纤毛”。这些细胞器在运动和感知环境方面具有各种重要功能。可运动的纤毛对于细胞的移动和液体在表面上的移动都是必不可少的。运动纤毛的波形需要大型的大分子马达；这些是纤毛动力细胞。这些动力蛋白复合物通过一种称为预组装的途径在细胞质中组装，然后运输到纤毛中。这一过程中的缺陷导致了一种异质性的人类疾病，称为原发性纤毛运动障碍，其结果是，例如，在发育过程中呼吸道纤毛、精子和结纤毛的运动性受到破坏。预组装途径的机制尚不完全清楚。在这项研究中，我们利用了绿藻莱茵衣藻（Chlamydomonas reinhardtii）保守的DYX1C1/PF23基因的突变。一个保守结构域（DYX）的缺失表明大多数纤毛动力蛋白无法组装。内臂动力总成的预装尤其受到影响。我们发现，如果动力蛋白臂没有组装，细胞质中的动力蛋白亚基是不稳定的。我们认为DYX1C1可能作为其他预组装因子和动力蛋白亚基的支架发挥作用。
Cytoplasmic assembly of ciliary dyneins, a process known as preassembly, requires numerous non-dynein proteins, but the identities and functions of these proteins are not fully elucidated. Here, we show that the classical Chlamydomonas motility mutant pf23 is defective in the Chlamydomonas homolog of DYX1C1. The pf23 mutant has a 494 bp deletion in the DYX1C1 gene and expresses a shorter DYX1C1 protein in the cytoplasm. Structural analyses, using cryo-ET, reveal that pf23 axonemes lack most of the inner dynein arms. Spectral counting confirms that DYX1C1 is essential for the assembly of the majority of ciliary inner dynein arms (IDA) as well as a fraction of the outer dynein arms (ODA). A C-terminal truncation of DYX1C1 shows a reduction in a subset of these ciliary IDAs. Sucrose gradients of cytoplasmic extracts show that preassembled ciliary dyneins are reduced compared to wild-type, which suggests an important role in dynein complex stability. The role of PF23/DYX1C1 remains unknown, but we suggest that DYX1C1 could provide a scaffold for macromolecular assembly. Most animal cells have antenna-like organelles called “cilia”. These organelles have various important functions both in motility and sensing the environment. Motile cilia are essential for moving cells as well as moving fluids across a surface. The waveform of motile cilia requires large macromolecular motors; these are the ciliary dyneins. These dynein complexes are assembled in the cytoplasm in a pathway called preassembly, and then transported into cilia. Defects in this process cause a heterogeneous human disease called primary ciliary dyskinesia that results, for example, in the disruption of the motility of respiratory tract cilia, sperm and nodal cilia during development. The mechanisms of the preassembly pathway are not fully understood. In this study, we use a mutation in the well-conserved DYX1C1/PF23 gene of the green alga, Chlamydomonas reinhardtii. Loss of a conserved domain (DYX) reveals a failure to assemble most ciliary dyneins. Preassembly of inner arm dyneins is particularly affected. We find that if dynein arms are not assembled, dynein subunits in the cytoplasm are unstable. We suggest that DYX1C1 may play a role as a scaffold for other preassembly factors and the dynein subunits.
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影响因子：
10.1
作者：
Brown JM;Witman GB
通讯作者：
Witman GB
影响因子：
3.3
作者：
Dean, Anudariya B.;Mitchell, David R.
通讯作者：
Mitchell, David R.
影响因子：
9.8
作者：
Cope, N;Harold, D;Williams, J
通讯作者：
Williams, J
DOI：
10.1016/j.cub.2014.08.047
发表时间：
2014-10-06
期刊：
Current biology : CB
影响因子：
--
作者：
Brooks ER;Wallingford JB
通讯作者：
Wallingford JB
影响因子：
7.5
作者：
Drummond, Iain A.
通讯作者：
Drummond, Iain A.