Faculty of Life Sciences, University of Manchester, Manchester, M13 9PT, UK.
J Cell Sci. 2010 Jan 15;123(Pt 2):202-12. doi: 10.1242/jcs.059337.
LIS1, NDE1 and NDEL1 modulate cytoplasmic dynein function in several cellular contexts. However, evidence that they regulate dynein-dependent organelle positioning is limited. Here, we show that depletion of NDE1 or NDEL1 alone profoundly affected the organisation of the Golgi complex but did not cause it to disperse, and slightly affected the position of endocytic compartments. However, striking dispersal of organelles was observed when both NDE1 and NDEL1 were depleted. A substantial portion of NDE1 and NDEL1 is membrane associated, and depletion of these proteins led to complete loss of dynein from membranes. Knockdown of LIS1 also caused the Golgi complex to fragment and disperse throughout the cell, and caused endocytic compartments to relocalise to the periphery. Depletion of LIS1, which is primarily cytosolic, led to partial loss of membrane-associated dynein, without affecting NDE1 and NDEL1. These data suggest that NDE1 and NDEL1 act upstream of LIS1 in dynein recruitment, and/or activation, on the membrane. Consistent with this hypothesis, expression of exogenous NDE1 or NDEL1 rescued the effects of LIS1 depletion on Golgi organisation, whereas LIS1 was only partially effective at rescuing the loss of NDE1 and NDEL1.
LIS1、NDE1 和 NDEL1 在几种细胞环境中调节细胞质动力蛋白的功能。然而，它们调节动力蛋白依赖性细胞器定位的证据有限。在这里，我们表明单独耗尽 NDE1 或 NDEL1 会严重影响高尔基体复合物的组织，但不会导致其分散，并轻微影响内吞隔室的位置。然而，当耗尽 NDE1 和 NDEL1 时，观察到细胞器的明显分散。NDE1 和 NDEL1 的很大一部分与膜相关，耗尽这些蛋白质会导致动力蛋白从膜上完全丢失。LIS1 的敲低也会导致高尔基体复合物碎裂并分散到整个细胞中，并导致内吞隔室重新定位到细胞边缘。LIS1 主要存在于细胞质中，耗尽它会导致膜结合动力蛋白的部分丢失，而不影响 NDE1 和 NDEL1。这些数据表明，NDE1 和 NDEL1 在 LIS1 招募和/或激活动力蛋白方面在上游起作用，作用于膜上。与这一假设一致，表达外源 NDE1 或 NDEL1 可以挽救 LIS1 耗尽对高尔基体组织的影响，而 LIS1 只能部分挽救 NDE1 和 NDEL1 的缺失。
