Wordeman L, Cande W Z
Cell. 1987 Aug 14;50(4):535-43. doi: 10.1016/0092-8674(87)90026-2.
Mitotic spindles isolated from the diatom Stephanopyxis turris consist of two half-spindles of closely interdigitating microtubules that slide relative to one another in the presence of ATP, reinitiating spindle elongation (anaphase B) in vitro. Purified spindles that have been exposed to ATP-gamma-S undergo ATP-dependent reactivation more readily than do control spindles. Thiophosphorylated proteins in such spindles are located in the spindle midzone, kinetochores, and a portion of the pole complex. One major thiophosphorylated peptide of 205 kd is detected in extracts prepared from spindles labeled with [35S]ATP-gamma-S, and is also localized in the spindle midzone by using an antibody that recognizes thiophosphorylated proteins. It is likely that this 205 kd peptide is either a positive regulator or mechanochemical transducer of microtubule sliding when it is in a phosphorylated state.
从硅藻塔形辐杆藻中分离出的有丝分裂纺锤体由两个半纺锤体组成，半纺锤体中的微管紧密交叉，在ATP存在的情况下，它们会相对滑动，在体外重新启动纺锤体伸长（后期B）。与对照纺锤体相比，暴露于ATP-γ-S的纯化纺锤体更容易发生ATP依赖性再激活。此类纺锤体中的硫代磷酸化蛋白位于纺锤体中区、动粒和部分极复合体中。在用[35S]ATP-γ-S标记的纺锤体制备的提取物中检测到一种205 kd的主要硫代磷酸化肽，并且通过使用识别硫代磷酸化蛋白的抗体也将其定位在纺锤体中区。当处于磷酸化状态时，这种205 kd的肽很可能是微管滑动的正调节因子或机械化学转导器。
