Thoumine Olivier
CNRS UMR 5091, Institut Magendie, Université Bordeaux 2, Bordeaux, France.
Cell Adh Migr. 2008 Oct-Dec;2(4):263-7. doi: 10.4161/cam.2.4.7274. Epub 2008 Oct 24.
The migration of neuronal growth cones, driving axon extension, is a fascinating process which has been subject of intense investigation over several decades. Many of the key underlying molecules, in particular adhesion proteins at the cell membrane which allow for target recognition and binding, and cytoskeleton filaments and motors which power locomotion have been identified. However, the precise mechanisms by which growth cones coordinate, in time and space, the transmission of forces generated by the cytoskeleton to the turnover of adhesion proteins are still partly unresolved. To get a better grasp at these processes, we put here in relation the turnover rate of ligand/receptor adhesions and the degree of mechanical coupling between cell adhesion receptors and the actin rearward flow. These parameters were obtained recently for N-cadherin and IgCAM based adhesions using ligand-coated microspheres in combination with optical tweezers and photo-bleaching experiments. We show that the speed of growth cone migration requires both a fairly rapid adhesion dynamics and a strong physical connection between adhesive sites and the cytoskeleton.
神经元生长锥的迁移驱动轴突延伸，这是一个几十年来一直受到深入研究的迷人过程。许多关键的基础分子已被确定，特别是细胞膜上允许靶标识别和结合的粘附蛋白，以及为运动提供动力的细胞骨架细丝和马达。然而，生长锥如何在时间和空间上协调由细胞骨架产生的力向粘附蛋白周转的传递的精确机制仍部分未得到解决。为了更好地理解这些过程，我们在此阐述了配体/受体粘附的周转率以及细胞粘附受体与肌动蛋白向后流动之间的机械偶联程度。最近，使用配体包被的微球结合光镊和光漂白实验，获得了基于N-钙粘蛋白和IgCAM的粘附的这些参数。我们表明，生长锥迁移的速度既需要相当快速的粘附动力学，也需要粘附位点与细胞骨架之间牢固的物理连接。
