Ishikawa Hiroaki, Ide Takahiro, Yagi Toshiki, Jiang Xue, Hirono Masafumi, Sasaki Hiroyuki, Yanagisawa Haruaki, Wemmer Kimberly A, Stainier Didier Yr, Qin Hongmin, Kamiya Ritsu, Marshall Wallace F
Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States.
Elife. 2014 Jan 1;3:e01566. doi: 10.7554/eLife.01566.
Cilia/flagella are assembled and maintained by the process of intraflagellar transport (IFT), a highly conserved mechanism involving more than 20 IFT proteins. However, the functions of individual IFT proteins are mostly unclear. To help address this issue, we focused on a putative IFT protein TTC26/DYF13. Using live imaging and biochemical approaches we show that TTC26/DYF13 is an IFT complex B protein in mammalian cells and Chlamydomonas reinhardtii. Knockdown of TTC26/DYF13 in zebrafish embryos or mutation of TTC26/DYF13 in C. reinhardtii, produced short cilia with abnormal motility. Surprisingly, IFT particle assembly and speed were normal in dyf13 mutant flagella, unlike in other IFT complex B mutants. Proteomic and biochemical analyses indicated a particular set of proteins involved in motility was specifically depleted in the dyf13 mutant. These results support the concept that different IFT proteins are responsible for different cargo subsets, providing a possible explanation for the complexity of the IFT machinery. DOI: http://dx.doi.org/10.7554/eLife.01566.001.
纤毛/鞭毛通过鞭毛内运输（IFT）过程进行组装和维持，这是一种高度保守的机制，涉及20多种IFT蛋白。然而，单个IFT蛋白的功能大多尚不清楚。为了帮助解决这个问题，我们聚焦于一种假定的IFT蛋白TTC26/DYF13。通过实时成像和生化方法，我们发现TTC26/DYF13在哺乳动物细胞和莱茵衣藻中是一种IFT复合体B蛋白。在斑马鱼胚胎中敲低TTC26/DYF13或在莱茵衣藻中使TTC26/DYF13发生突变，会产生具有异常运动能力的短纤毛。令人惊讶的是，与其他IFT复合体B突变体不同，dyf13突变体鞭毛中的IFT颗粒组装和速度是正常的。蛋白质组学和生化分析表明，dyf13突变体中一组与运动相关的特定蛋白质被特异性耗尽。这些结果支持了不同的IFT蛋白负责不同货物亚群的概念，为IFT机制的复杂性提供了一种可能的解释。DOI: http://dx.doi.org/10.7554/eLife.01566.001
