Membrane phospholipid dynamics and cytoskeletal organization: Regulation of actin filament assembly by redistribution of membrane surface phospholipid

利用一种新型多肽探针Ro09-0198与磷脂酰乙醇胺(PE)在生物膜上形成紧密的等摩尔复合体，分析了PE在CHO细胞分裂过程中的细胞表面运动。我们发现，在胞质分裂末期，质膜PE的翻转在分裂沟处明显增强，而在有丝分裂末期，加入多肽-链霉亲和素复合体引起的PE对细胞表面的捕获阻碍了胞质分裂。进一步的分析表明，质膜磷脂的重新分布是肌动蛋白细丝组装的调节因子，在调节质膜和细胞骨架之间的协调运动中起着至关重要的作用。利用酵母和CHO突变细胞研究了参与磷脂动力学和细胞骨架重组之间的串扰的分子，这些突变细胞是通过对PE结合肽的敏感性改变而被选择的。

Using a novel peptide probe, Ro09-0198, which specifically forms a tight equimolar complex with phosphatidylethanoalmaine (PE) on biological membranes, we have analyzed the cell surface movement of PE in dividing CHO cells. We found that flip-flop of plasma membrane PE was markedly enhanced at the cleavage furrow during the late telophase of cytokinesis and that cell surface trapping of PE induced by adding the peptide-streptavidin complex to the mitotic cells blocked cytokinesis at the late telophase. Further analysis have shown that the redistribution of plasma membrane phospholipids acts as a regulator of actin filament assembly and play a crucial role in mediating a coordinate movement between plasma membrane and cytoskeleton. Molecules involved in the cross-talk between the phospholipid dynamics and cytoskeletal reorganization have been investigated using yeast and CHO mutant cells which were selected by their altered sensitivity to the PE-binding peptide.