Structural and functional analysis of novel dyneins localized to the ciliary proximal region

我们分析了轴丝含量低于其他主要类型动力蛋白的次要类型动力蛋白的结构和功能。在这里，我们发现，在缺乏ATP的情况下，三种微小的动力蛋白中的一种比大多数衣藻动力蛋白与微管的结合更强。此外，使用冷冻电子断层扫描和亚断层图像平均，我们发现每个微小的动力蛋白位于睫状神经近端区域，而不是特定的主要动力蛋白。此外，我们还发现了一个新的巨型动力蛋白，它是衣藻中最后一个尚未确定的动力蛋白重链，位于九个双线微管中的一个的近端区域。这是首次在该单一生物体中鉴定出动力蛋白重链的全部基因产物。

We analyzed the structure and function of minor-type dyneins whose axonemal contents are lower than other major-type dyneins. Here we found that one of three minor dyneins more strongly bind to microtubules than most of Chlamydomonas dyneins in the absence of ATP. In addition, using cryoelectron tomography and subtomogram averaging, we found that each minor dynein locates to the ciliary proximal region in place of a specific major dynein. Furthermore, we found that a novel gigantic dynein, which has been the last dynein heavy chain remained to be identified in Chlamydomonas, localizes to the proximal region of one of nine doublet microtubules. This is the first report that all the gene products of dynein heavy chain have been identified in the singleorganism.