European Molecular Biology Laboratory, Cell Biology and Biophysics Program, Heidelberg, Germany.
PLoS One. 2010 Dec 2;5(12):e14201. doi: 10.1371/journal.pone.0014201.
Microtubules are essential for a variety of fundamental cellular processes such as organelle positioning and control of cell shape. Schizosaccharomyces pombe is an ideal organism for studying the function and organization of microtubules into bundles in interphase cells. Using light microscopy and electron tomography we analyzed the bundle organization of interphase microtubules in S. pombe. We show that cells lacking ase1p and klp2p still contain microtubule bundles. In addition, we show that ase1p is the major determinant of inter-microtubule spacing in interphase bundles since ase1 deleted cells have an inter-microtubule spacing that differs from that observed in wild-type cells. We then identified dis1p, a XMAP215 homologue, as factor that promotes the stabilization of microtubule bundles. In wild-type cells dis1p partially co-localized with ase1p at regions of microtubule overlap. In cells deleted for ase1 and klp2, dis1p accumulated at the overlap regions of interphase microtubule bundles. In cells lacking all three proteins, both microtubule bundling and inter-microtubule spacing were further reduced, suggesting that Dis1p contributes to interphase microtubule bundling.
微管对于多种基本的细胞过程是必不可少的，例如细胞器的定位和细胞形状的控制。裂殖酵母是研究间期细胞中微管成束的功能和组织的理想生物。我们使用荧光显微镜和电子断层扫描分析了裂殖酵母间期微管的束状结构。我们发现，缺乏 ase1p 和 klp2p 的细胞仍然含有微管束。此外，我们还表明 ase1p 是间期束中微管间距离的主要决定因素，因为 ase1 缺失的细胞的微管间距离与野生型细胞观察到的不同。然后，我们确定了 dis1p，一种 XMAP215 同源物，是促进微管束稳定的因素。在野生型细胞中，dis1p 与 ase1p 在微管重叠区域部分共定位。在 ase1 和 klp2 缺失的细胞中，dis1p 在间期微管束的重叠区域积累。在缺乏这三种蛋白质的细胞中，微管成束和微管间距离进一步减少，表明 Dis1p 有助于间期微管成束。
