Dictyostelium DdCP224 is a microtubule-associated protein and a permanent centrosomal resident involved in centrosome duplication.
Dictyostelium DdCP224 is a microtubule-associated protein and a permanent centrosomal resident involved in centrosome duplication.
复制标题
Dictyostelium DdCP224 是一种微管相关蛋白，是参与中心体复制的永久中心体居民。
作者：
R. Gräf;C. Daunderer;M. Schliwa
通过免疫筛选获得了一个编码224-kDa盘基网柄藻中心体蛋白（DdCP 224）的cDNA。在整个细胞周期中，在中心体和沿着微管处检测到DdCP 224，但较弱。中心体定位不需要微管，这表明DdCP 224是一个真正的中心体组件。DdCP 224与包括人TOGp和酵母Stu 2 p在内的一类弱保守的微管相关蛋白具有序列同一性。Stu 2 p的大小仅约为100 kDa，对应于DdCP 224的N-末端一半。DdCP 224的N-和C-末端的一半的功能进行了研究，在相应的GFP融合突变体。令人惊讶的是，N-末端构建体仅显示胞质定位，而C-末端构建体仅定位于中心体。这是出乎意料的，因为Stu 2 p位于主轴杆体处。全长DdCP 224-GFP存在于中心体和沿着微管。此外，它在体外结合微管，不像两个截短的突变体。因此，中心体结合是由C-末端的一半和微管结合可能需要的N-和C-末端的一半的相互作用。有趣的是，表达全长DdCP 224-GFP的细胞表现出额外的中心体，并显示出胞质分裂缺陷，这表明DdCP 224在中心体复制中起着重要作用。这些特征在已知的中心体蛋白中是独特的。
A cDNA encoding a 224-kDa Dictyostelium discoideum centrosomal protein (DdCP224) was isolated by immunoscreening. DdCP224 was detected at the centrosome and, more weakly, along microtubules throughout the entire cell cycle. Centrosomal localization does not require microtubules, suggesting that DdCP224 is a genuine centrosomal component. DdCP224 exhibits sequence identity to a weakly conserved class of microtubule-associated proteins including human TOGp and yeast Stu2p. Stu2p has a size of only approximately 100 kDa and corresponds to the N-terminal half of DdCP224. The functions of the N- and C-terminal halves of DdCP224 were investigated in the corresponding GFP-fusion mutants. Surprisingly, the N-terminal construct showed only cytosolic localization, whereas the C-terminal construct localized exclusively to the centrosome. This is unexpected because Stu2p is localized at the spindle pole body. Full-length DdCP224-GFP was present both at centrosomes and along microtubules. Furthermore, it bound to microtubules in vitro, unlike the two truncated mutants. Thus centrosome binding is determined by the C-terminal half and microtubule binding may require the interaction of the N- and C-terminal halves. Interestingly, cells expressing full-length DdCP224-GFP exhibit supernumerary centrosomes and show a cytokinesis defect, suggesting that DdCP224 plays an important role in centrosome duplication. These features are unique among the known centrosomal proteins.
影响因子：
11.4
作者：
MANSTEIN, DJ;TITUS, MA;SPUDICH, JA
通讯作者：
SPUDICH, JA