Emoto K, Kobayashi T, Yamaji A, Aizawa H, Yahara I, Inoue K, Umeda M
Department of Inflammation Research, Tokyo Metropolitan Institute of Medical Science (RINSHOKEN), Japan.
Proc Natl Acad Sci U S A. 1996 Nov 12;93(23):12867-72. doi: 10.1073/pnas.93.23.12867.
Ro09-0198 is a tetracyclic polypeptide of 19 amino acids that recognizes strictly the structure of phosphatidylethanolamine (PE) and forms a tight equimolar complex with PE on biological membranes. Using the cyclic peptide coupled with fluorescence-labeled streptavidin, we have analyzed the cell surface localization of PE in dividing Chinese hamster ovary cells. We found that PE was exposed on the cell surface specifically at the cleavage furrow during the late telophase of cytokinesis. PE was exposed on the cell surface only during the late telophase and no alteration in the distribution of the plasma membrane-bound cyclic peptide was observed during the cytokinesis, suggesting that the surface exposure of PE reflects the enhanced scrambling of PE at the cleavage furrow. Furthermore, cell surface immobilization of PE induced by adding the cyclic peptide coupled with streptavidin to prometaphase cells effectively blocked the cytokinesis at late telophase. The peptide-streptavidin complex treatment had no effect on furrowing, rearrangement of microtubules, and nuclear reconstitution, but specifically inhibited both actin filament disassembly at the cleavage furrow and subsequent membrane fusion. These results suggest that the redistribution of the plasma membrane phospholipids is a crucial step for cytokinesis and the cell surface PE may play a pivotal role in mediating a coordinate movement between the contractile ring and plasma membrane to achieve successful cell division.
Ro09-0198是一种由19个氨基酸组成的四环多肽,它能严格识别磷脂酰乙醇胺(PE)的结构,并在生物膜上与PE形成紧密的等摩尔复合物。利用与荧光标记链霉亲和素偶联的环肽,我们分析了分裂中的中国仓鼠卵巢细胞中PE的细胞表面定位。我们发现,在胞质分裂末期的晚末期,PE特异性地暴露在细胞表面的分裂沟处。PE仅在晚末期暴露于细胞表面,并且在胞质分裂过程中未观察到质膜结合环肽的分布发生改变,这表明PE的表面暴露反映了其在分裂沟处的增强的翻转。此外,向有丝分裂前期细胞中添加与链霉亲和素偶联的环肽诱导的PE细胞表面固定有效地在晚末期阻断了胞质分裂。肽-链霉亲和素复合物处理对沟的形成、微管的重排和核重建没有影响,但特异性地抑制了分裂沟处的肌动蛋白丝解聚和随后的膜融合。这些结果表明,质膜磷脂的重新分布是胞质分裂的关键步骤,细胞表面的PE可能在介导收缩环与质膜之间的协调运动以实现成功的细胞分裂中起关键作用。