Konopka Catherine A, Backues Steven K, Bednarek Sebastian Y
Program in Cellular and Molecular Biology, University of Wisconsin, Madison, Wisconsin 53706, USA.
Plant Cell. 2008 May;20(5):1363-80. doi: 10.1105/tpc.108.059428. Epub 2008 May 23.
Plant morphogenesis depends on polarized exocytic and endocytic membrane trafficking. Members of the Arabidopsis thaliana dynamin-related protein 1 (DRP1) subfamily are required for polarized cell expansion and cytokinesis. Using a combination of live-cell imaging techniques, we show that a functional DRP1C green fluorescent fusion protein (DRP1C-GFP) was localized at the division plane in dividing cells and to the plasma membrane in expanding interphase cells. In both tip growing root hairs and diffuse-polar expanding epidermal cells, DRP1C-GFP organized into dynamic foci at the cell cortex, which colocalized with a clathrin light chain fluorescent fusion protein (CLC-FFP), suggesting that DRP1C may participate in clathrin-mediated membrane dynamics. DRP1C-GFP and CLC-GFP foci dynamics are dependent on cytoskeleton organization, cytoplasmic streaming, and functional clathrin-mediated endocytic traffic. Our studies provide insight into DRP1 and clathrin dynamics in the plant cell cortex and indicate that the clathrin endocytic machinery in plants has both similarities and striking differences to that in mammalian cells and yeast.
植物形态发生依赖于极性分泌和内吞膜运输。拟南芥动力蛋白相关蛋白1（DRP1）亚家族成员是极性细胞扩张和胞质分裂所必需的。通过结合活细胞成像技术，我们发现功能性DRP1C绿色荧光融合蛋白（DRP1C-GFP）在分裂细胞的分裂平面以及间期扩展细胞的质膜上定位。在顶端生长的根毛和扩散极性扩展的表皮细胞中，DRP1C-GFP在细胞皮层组织成动态焦点，与网格蛋白轻链荧光融合蛋白（CLC-FFP）共定位，表明DRP1C可能参与网格蛋白介导的膜动力学。DRP1C-GFP和CLC-GFP焦点动态依赖于细胞骨架组织、细胞质流动以及功能性网格蛋白介导的内吞运输。我们的研究为植物细胞皮层中DRP1和网格蛋白的动态提供了见解，并表明植物中的网格蛋白内吞机制与哺乳动物细胞和酵母中的既有相似之处又有显著差异。
