Therefore, all eukaryotic cells must alter microtubule organization between the cytoplasmic array and the spindle when entering or exiting mitosis. Many studies in recent decades have identified a number of microtubule regulators. For example, the c-tubulin complex is required for microtubule nucleation and controls the distribution and polarized growth of microtubules. Also, microtubule associated proteins include motor proteins such as kinesin family proteins and dynein, factors involved in stabilization or destabilization of microtubules and factors that align or slide microtubule bundles. The functional state of certain microtubule regulators varies during the cell cycle. In animal cells, the c-tubulin complex is Schizandrin-B phosphorylated by Aurora A kinase for nucleation of microtubules to stabilize the spindle. Aurora A also phosphorylates the conserved MAP TACC to recruit the TACC to the centrosomes. Alp7, the fission yeast TACC ortholog, translocates from the cytoplasm to the nucleus upon entry into mitosis, which is critical for spindle formation. A conserved microtubule bundling factor, Ase1/PRC1, as well as Klp9 are dephosphorylated to bind to each other in anaphase, and the interaction is required for proper spindle elongation. Although there is currently vast knowledge on this subject, how each aspect of microtubule functions and regulations are linked to each other at the molecular level remains largely unknown. More specifically,Lithospermoside although much work has been done on microtubule functions and dynamics, the molecular mechanism controlling microtubule regulation at specific cell cycle transitions remain largely unknown. For instance, it is not clear how microtubules are reorganized at mitotic entry and exit. In fission yeast, the reorganization of microtubules during the cell cycle can be summarized as follows. During interphase, a cytoplasmic microtubule array forms relatively uniformly along the cylinder formed by the yeast cell. Microtubule organizing centers in interphase are thought to localize around the nucleus. Upon entry into mitosis, the cytoplasmic array of microtubules is disassembled and the mitotic spindle is formed in the nucleus. The main MTOC during mitosis is the SPB in Schizosaccharomyces pombe.