Leduc Cécile, Campàs Otger, Joanny Jean-François, Prost Jacques, Bassereau Patricia
Centre de Physique Moléculaire Optique et Hertzienne, Université Bordeaux 1, France.
Biochim Biophys Acta. 2010 Jul;1798(7):1418-26. doi: 10.1016/j.bbamem.2009.11.012. Epub 2009 Nov 27.
Membrane nanotubes are ubiquitous in eukaryotic cells due to their involvement in the communication between many different membrane compartments. They are very dynamical structures, which are generally extended along the microtubule network. One possible mechanism of tube formation involves the action of molecular motors, which can generate the necessary force to pull the tubes along the cytoskeleton tracks. However, it has not been possible so far to image in living organisms simultaneously both tube formation and the molecular motors involved in the process. The reasons for this are mainly technological. To overcome these limitations and to elucidate in detail the mechanism of tube formation, many experiments have been developed over the last years in cell-free environments. In the present review, we present the results, which have been obtained in vitro either in cell extracts or with purified and artificial components. In particular, we will focus on a biomimetic system, which involves Giant Unilamellar Vesicles, kinesin-1 motors and microtubules in the presence of ATP. We present both theoretical and experimental results based on fluorescence microscopy that elucidate the dynamics of membrane tube formation, growth and stalling.
膜纳米管在真核细胞中普遍存在，因为它们参与了许多不同膜区室之间的通讯。它们是非常动态的结构，通常沿着微管网络延伸。一种可能的管形成机制涉及分子马达的作用，分子马达可以产生必要的力，沿着细胞骨架轨道拉动这些管子。然而，到目前为止，还无法在活生物体中同时成像管形成过程和该过程中涉及的分子马达。主要原因是技术问题。为了克服这些限制并详细阐明管形成的机制，在过去几年中已经在无细胞环境中开展了许多实验。在本综述中，我们展示了在体外细胞提取物中或使用纯化的人工成分所获得的结果。特别是，我们将重点关注一个仿生系统，该系统在ATP存在的情况下涉及巨型单层囊泡、驱动蛋白-1马达和微管。我们基于荧光显微镜展示了理论和实验结果，这些结果阐明了膜管形成、生长和停滞的动态过程。
