Liu Chenshu, Chuang Jen-Zen, Sung Ching-Hwa, Mao Yinghui
a Department of Pathology and Cell Biology ; Columbia University College of Physicians and Surgeons ; New York , NY USA.
Cell Cycle. 2015;14(9):1379-88. doi: 10.1080/15384101.2014.1000217.
Dynein light chains are accessory subunits of the cytoplasmic dynein complex, a minus-end directed microtubule motor. Here, we demonstrate that the dynein light chain Tctex-1 associates with unattached kinetochores and is essential for accurate chromosome segregation. Tctex-1 knockdown in cells does not affect the localization and function of dynein at the kinetochore, but produces a prolonged mitotic arrest with a few misaligned chromosomes, which are subsequently missegregated during anaphase. This function is independent of Tctex-1's association with dynein. The kinetochore localization of Tctex-1 is independent of the ZW10-dynein pathway, but requires the Ndc80 complex. Thus, our findings reveal a dynein independent role of Tctex-1 at the kinetochore to enhance the stability of kinetochore-microtubule attachment.
动力蛋白轻链是胞质动力蛋白复合体的辅助亚基，胞质动力蛋白复合体是一种向微管负端移动的马达蛋白。在此，我们证明动力蛋白轻链Tctex-1与未附着的动粒相关联，并且对于精确的染色体分离至关重要。在细胞中敲低Tctex-1不会影响动力蛋白在动粒处的定位和功能，但会导致有丝分裂长期停滞，并出现一些染色体排列错误，这些染色体随后在后期会发生错误分离。该功能独立于Tctex-1与动力蛋白的关联。Tctex-1在动粒处的定位独立于ZW10-动力蛋白途径，但需要Ndc80复合体。因此，我们的研究结果揭示了Tctex-1在动粒处具有独立于动力蛋白的作用，可增强动粒-微管附着的稳定性。
