cut11+:: A gene required for cell cycle-dependent spindle pole body anchoring in the nuclear envelope and bipolar spindle formation in Schizosaccharomyces pombe
cut11+:: A gene required for cell cycle-dependent spindle pole body anchoring in the nuclear envelope and bipolar spindle formation in Schizosaccharomyces pombe
复制标题
DOI：
10.1091/mbc.9.10.2839
复制
发表时间：
1998-10-01
影响因子：
3.3
通讯作者：
McIntosh, JR
中科院分区：
文献类型：
--
作者：
West, RR;Vaisberg, EV;McIntosh, JR
裂殖酵母的“切割”突变体在纺锤体形成和/或染色体分离方面存在缺陷，但它们在细胞周期中进行，导致致死。对Cut11(+)的温度敏感等位基因分析表明，该基因是形成功能性双极纺锤体所必需的。微管蛋白和DNA的荧光探针显示纺锤体结构有缺陷。通过连续切片和电子显微镜对突变纺锤体的三维重建表明，纺锤体极体要么不能完成正常复制，要么在核质中自由漂浮。绿色荧光蛋白标记的Cut11p的定位显示在整个细胞周期中呈点状核膜染色，SPBS染色从早前期到中期。SPB的这种定位与细胞周期中SPB插入核膜的时间相关。免疫电子显微镜证实Cut11p定位于有丝分裂的SPBS和核孔复合体。克隆和测序结果表明，Cut11(+)编码一个新的蛋白，具有7个跨膜结构域，与酿酒酵母基因Ndc1同源。这些数据表明，Cut11p与核孔复合体和有丝分裂SPBS结合，作为核膜上的锚；这一作用对有丝分裂是必不可少的。
The "cut" mutants of Schizosaccharomyces pombe are defective in spindle formation and/or chromosome segregation, but they proceed through the cell cycle, resulting in lethality. Analysis of temperature-sensitive alleles of cut11(+) suggests that this gene is required for the formation of a functional bipolar spindle. Defective spindle structure was revealed with fluorescent probes for tubulin and DNA. Three-dimensional reconstruction of mutant spindles by serial sectioning and electron microscopy showed that the spindle pole bodies (SPBs) either failed to complete normal duplication or were free floating in the nucleoplasm. Localization of Cut11p tagged with the green fluorescent protein showed punctate nuclear envelope staining throughout the cell cycle and SPBs staining from early prophase to mid anaphase. This SPB localization correlates with the time in the cell cycle when SPBs are inserted into the nuclear envelope. Immunoelectron microscopy confirmed the localization of Cut11p to mitotic SPBs and nuclear pore complexes. Cloning and sequencing showed that cut11(+) encodes a novel protein with seven putative membrane-spanning domains and homology to the Saccharomyces cerevisiae gene NDC1. These data suggest that Cut11p associates with nuclear pore complexes and mitotic SPBs as an anchor in the nuclear envelope; this role is essential for mitosis.