National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
GM083122
米国
March of Dimes Foundation
米国
引用
ジャーナル: Science / 年: 2018 タイトル: Asymmetric distribution and spatial switching of dynein activity generates ciliary motility. 著者: Jianfeng Lin / Daniela Nicastro / 要旨: Motile cilia and flagella are essential, highly conserved organelles, and their motility is driven by the coordinated activities of multiple dynein isoforms. The prevailing "switch-point" hypothesis ...Motile cilia and flagella are essential, highly conserved organelles, and their motility is driven by the coordinated activities of multiple dynein isoforms. The prevailing "switch-point" hypothesis posits that dyneins are asymmetrically activated to drive flagellar bending. To test this model, we applied cryo-electron tomography to visualize activity states of individual dyneins relative to their locations along beating flagella of sea urchin sperm cells. As predicted, bending was generated by the asymmetric distribution of dynein activity on opposite sides of the flagellum. However, contrary to predictions, most dyneins were in their active state, and the smaller population of conformationally inactive dyneins switched flagellar sides relative to the bending direction. Thus, our data suggest a "switch-inhibition" mechanism in which force imbalance is generated by inhibiting, rather than activating, dyneins on alternating sides of the flagellum.
EMPIAR-10158 (タイトル: Cryo electron tomography of immotile sea urchin sperm flagella Data size: 13.8 Data #1: Tilt series of immotile sea urchin sperm flagella [tilt series])