Sheetz M P
Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
Mol Membr Biol. 1995 Jan-Mar;12(1):89-91. doi: 10.3109/09687689509038501.
The plasma membranes of migrating cells differentiate into at least three distinct domains as defined by the laser tweezers and the motile behaviour of particles bound to specific membrane glycoproteins. These domains are important for steps in the cell migration process. First, there is a domain at the leading edge of the lamellipodium where preferential attachment of cross-linked glycoproteins to the cytoskeleton occurs. The second domain at the rear of the cell is differentiated for releasing from substrata and shows decreased support of the membrane by the cytoskeleton. The third domain is the highly curved region(s) of the plasma membrane wherein certain membrane glycoproteins concentrate and is a site for controlling extension and attachment. Using single particle tracking and video analysis we find that the quantitative differences between plasma membrane domains are in the 4-20-fold range at any given time. These values are consistent with the rapid fluctuations seen in cell migration rates and directions. Over a longer time-scale, cells can possibly integrate these selective advantages to give a much higher overall fidelity for cell chemotaxis and neuronal path finding.
通过激光镊子以及与特定膜糖蛋白结合的粒子的运动行为来定义，迁移细胞的质膜至少可分化为三个不同的区域。这些区域对细胞迁移过程中的各个步骤很重要。首先，在片状伪足的前缘存在一个区域，交联糖蛋白在此优先附着于细胞骨架。细胞后部的第二个区域则是为从基质上脱离而分化，并且显示出细胞骨架对膜的支撑减少。第三个区域是质膜的高度弯曲区域，某些膜糖蛋白在此区域聚集，是控制延伸和附着的位点。使用单粒子追踪和视频分析，我们发现在任何给定时间，质膜区域之间的定量差异在4至20倍范围内。这些值与细胞迁移速率和方向上观察到的快速波动一致。在更长的时间尺度上，细胞可能整合这些选择性优势，从而为细胞趋化性和神经元路径寻找提供更高的整体保真度。
