The role of pre- and post-anaphase microtubules in the cytokinesis phase of the cell cycle
| Autor: | David B. Hoffman, Julie C. Canman, Edward D. Salmon |
|---|---|
| Rok vydání: | 2000 |
| Předmět: |
Aurora B kinase
Cell Cycle Proteins Biology Microtubules General Biochemistry Genetics and Molecular Biology Cell Line Fungal Proteins Animals Cleavage furrow Mitosis Antibodies Fungal Agricultural and Biological Sciences(all) Phycoplast Biochemistry Genetics and Molecular Biology(all) Nocodazole Calcium-Binding Proteins Cell Cycle Nuclear Proteins Cell biology Midbody Spindle checkpoint Anaphase Carrier Proteins General Agricultural and Biological Sciences Astral microtubules Cell Division Cytokinesis |
| Zdroj: | Current Biology. 10:611-614 |
| ISSN: | 0960-9822 |
| DOI: | 10.1016/s0960-9822(00)00490-5 |
| Popis: | The cytokinesis phase, or C phase, of the cell cycle results in the separation of one cell into two daughter cells after the completion of mitosis. Although it is known that microtubules are required for proper positioning of the cytokinetic furrow [1] [2], the role of pre-anaphase microtubules in cytokinesis has not been clearly defined for three key reasons. First, inducing microtubule depolymerization or stabilization before the onset of anaphase blocks entry into anaphase and cytokinesis via the spindle checkpoint [3]. Second, microtubule organization changes rapidly at anaphase onset as the mitotic kinase, Cdc2-cyclin B, is inactivated [4]. Third, the time between the onset of anaphase and the initiation of cytokinesis is very short, making it difficult to unambiguously alter microtubule polymer levels before cytokinesis, but after inactivation of the spindle checkpoint. Here, we have taken advantage of the discovery that microinjection of antibodies to the spindle checkpoint protein Mad2 (mitotic arrest deficient) in prometaphase abrogates the spindle checkpoint, producing premature chromosome separation, segregation, and normal cytokinesis [5] [6]. To test the role of pre-anaphase microtubules in cytokinesis, microtubules were disassembled in prophase and prometaphase cells, the cells were then injected with anti-Mad2 antibodies and recorded through C phase. The results show that exit from mitosis in the absence of microtubules triggered a 50 minute period of cortical contractility that was independent of microtubules. Furthermore, upon microtubule reassembly during this contractile C-phase period, approximately 30% of the cells underwent chromosome poleward movement, formed a midzone microtubule complex, and completed cytokinesis. |
| Databáze: | OpenAIRE |
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