Warner Anne K, Keen James H, Wang Yu-Li
Department of Physiology, University of Massachusetts Medical School, 377 Plantation Street, Worcester, MA 01605, USA.
Traffic. 2006 Feb;7(2):205-15. doi: 10.1111/j.1600-0854.2005.00377.x.
Remodeling of cell membranes takes place during motile processes such as cell migration and cell division. Defects of proteins involved in membrane dynamics, including clathrin and dynamin, disrupt cytokinesis. To understand the function of clathrin-containing structures (CCS) in cytokinesis, we have expressed a green fluorescent protein (GFP) fusion protein of clathrin light chain a (GFP-clathrin) in NRK epithelial cells and recorded images of dividing cells near the ventral surface with a spinning disk confocal microscope. Punctate GFP-CCS underwent dynamic appearance and disappearance throughout the ventral surface. Following anaphase onset, GFP-CCS between separated chromosomes migrated toward the equator and subsequently disappeared in the equatorial region. Movements outside separating chromosomes were mostly random, similar to what was observed in interphase cells. Directional movements toward the furrow were dependent on both actin filaments and microtubules, while the appearance/disappearance of CCS was dependent on actin filaments but not on microtubules. These results suggest that CCS are involved in remodeling the plasma membrane along the equator during cytokinesis. Clathrin-containing structures may also play a role in transporting signaling or structural components into the cleavage furrow.
细胞膜重塑发生在诸如细胞迁移和细胞分裂等运动过程中。参与膜动力学的蛋白质缺陷，包括网格蛋白和发动蛋白，会破坏胞质分裂。为了了解含网格蛋白结构（CCS）在胞质分裂中的功能，我们在NRK上皮细胞中表达了网格蛋白轻链a的绿色荧光蛋白（GFP）融合蛋白（GFP-网格蛋白），并用转盘共聚焦显微镜记录了腹侧表面附近分裂细胞的图像。点状的GFP-CCS在整个腹侧表面经历了动态的出现和消失。后期开始后，分离染色体之间的GFP-CCS向赤道迁移，随后在赤道区域消失。分离染色体之外的运动大多是随机的，这与在间期细胞中观察到的情况相似。向沟的定向运动依赖于肌动蛋白丝和微管，而CCS的出现/消失依赖于肌动蛋白丝而不依赖于微管。这些结果表明，CCS参与了胞质分裂期间沿赤道重塑质膜的过程。含网格蛋白的结构也可能在将信号或结构成分运输到分裂沟中发挥作用。
