Local exposure of phosphatidylethanolamine on the yeast plasma membrane is implicated in cell polarity
Local exposure of phosphatidylethanolamine on the yeast plasma membrane is implicated in cell polarity
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DOI：
10.1111/j.1365-2443.2004.00782.x
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发表时间：
2004-10-01
期刊：
影响因子：
2.1
通讯作者：
Ohta, A
中科院分区：
文献类型：
--
作者：
Iwamoto, K;Kobayashi, S;Ohta, A
通过生物素化的Ro 09 -0198（Bio-Ro）探测酵母细胞的细胞表面磷脂酰乙醇胺（PE），其特异性结合PE，并用荧光素标记的链霉亲和素可视化。在酿酒酵母中，信号被观察到在假定的芽位，新兴的小芽皮层，有丝分裂晚期大芽细胞的芽颈和交配突起的尖端。在裂殖酵母中，信号出现在单核细胞的一端或两端以及有丝分裂晚期细胞的分裂面。这些位点是酵母细胞中的极化末端，这意味着PE暴露在细胞极化末端的细胞表面上。治疗S.用Ro 09 -0198处理酿酒酵母细胞导致在上述位点异常的F-肌动蛋白积累，这意味着PE的有限表面暴露涉及肌动蛋白细胞骨架的极化组织。此外，S.已知在荧光标记的PE的内化中有缺陷的酿酒酵母ros 3、dnf 1和dnf 2无效突变体以及组合突变体，除了野生型细胞的Bio-Ro染色位点之外，还在扩大的芽皮质处用Bio-Ro染色，这表明Ros 3 p、Dnf 1 p和Dnf 2 p参与了芽皮质处暴露的PE的恢复。
Cell surface phosphatidylethanolamine (PE) of the yeast cell was probed by biotinylated Ro09-0198 (Bio-Ro), which specifically binds to PE and was visualized with fluorescein-labelled streptavidin. In Saccharomyces cerevisiae, the signals were observed at the presumptive bud site, the emerging small bud cortex, the bud neck of the late mitotic large-budded cells and the tip of the mating projection. In Schizosaccharomyces pombe, the signals were observed at one end or both ends of mono-nucleated cells and the division plane of the late mitotic cells. These sites were polarized ends in the yeast cells, implying that PE is exposed on the cell surface at cellular polarized ends. Treatment of S. cerevisiae cells with Ro09-0198 resulted in aberrant F-actin accumulation at the above sites, implying that limited surface exposure of PE is involved in the polarized organization of the actin cytoskeleton. Furthermore, S. cerevisiae ros3, dnf1 and dnf2 null mutants, which were known to be defective in the internalization of fluorescence-labelled PE, as well as the combinatorial mutants, were stained with Bio-Ro at the enlarging bud cortex, in addition to the Bio-Ro-staining sites of wild-type cells, suggesting that Ros3p, Dnf1p and Dnf2p are involved in the retrieval of exposed PE at the bud cortex.