Figure 1.

Microtubule reorganization upon mitotic entry. (A) Reorganization of fission yeast microtubule structures during the cell cycle. The cytoplasmic array of interphase microtubules is remodeled into the mitotic nuclear spindle. N, Nucleus; C, Cytoplasm; MT, microtubules; SPB, Spindle Pole Body. (B) In Xenopus egg extract, the targets of Ran for microtubule assembly (called SAF), such as TPX2, are released around chromosomes by GTP-bound Ran, which forms a molecular gradient in the vicinity of the chromatin. Imp, Importin. (C) Localization of Alp7-YFP in interphase and mitosis. The arrow indicates nuclear accumulation of Alp7-YFP. Microtubules were visualized by mRFP-Atb2, whereas SPB was visualized by Cut12-CFP. Bar, 5 µm. (D) Diagram of Alp7/TACC structure. Note that the “Coiled-coil” region represents the conserved “TACC” domain. Exp, Exportin.