[The alp1-1315 mutation of the tubulin-folding cofactor D gene delays the mitosis initiation in cdc25-22 mutant cells of Schizosaccharomyces pombe].
Tubulin-folding cofactor D is necessary for the assembly of tubulin heterodimers and, possibly, plays additional roles in the cell. The effects of cofactor D, microtubules, and/or tubulin dimers on the mitosis initiation were studied in Schizosaccharomyces pombe. It was found for the first time that S. pombe cells with the alp1-1315 and cdc25-22 mutations remained highly viable at 36 degrees C for 8 h, in contrast to cells with the alp1-1315 mutation alone. The progression of cdc25-22 alp1-1315 cells through mitosis after a cell division arrest at 36 degrees C was described. When transferred to 25 degrees C, cdc25-22 alp1-1315 cells displayed a lag of approximately 30 min in Plo1-GFP appearance in the spindle pole body (SPB), 1 h in chromosome condensation, and 75 min in spindle formation. Thus, the initiation of mitosis in cdc25-22 alp1-1315 cells was delayed as compared with cdc25-22 cells. Since treatment of cdc25-22 cells with a microtubule-destabilizing drug during an arrest is known to cause a premitotic arrest with low activity of the mitosis-promoting factor (MPF), it was assumed that an impaired integrity of microtubules and/or lack of tubulin dimers in the nucleus were responsible for the delayed mitosis initiation in cdc25-22 alp1-1315 cells and in cdc25-22 cells treated with a microtubule-destabilizing drug. The progression through mitosis after a cdc25-22 arrest was extremely slow in cdc25-22 alp1-1315 cells, which was attributed to the de novo formation of tubulin dimers.
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D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D016200:Maturation-Promoting Factor / Q000235:genetics / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000235:genetics / Q000378:metabolism*; D008870:Microtubules / Q000235:genetics / Q000378:metabolism; D008938:Mitosis / Q000502:physiology*; D009154:Mutation; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics / Q000378:metabolism*; D008941:Spindle Apparatus / Q000235:genetics / Q000378:metabolism; D013997:Time Factors; D020666:ras-GRF1 / Q000235:genetics / Q000378:metabolism*
C110653:Alp1 protein, S pombe; D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D029702:Schizosaccharomyces pombe Proteins; C080926:cdc22 protein, S pombe; D020666:ras-GRF1; D016200:Maturation-Promoting Factor