Perturbation of the chromosomal binding of RCC1, Mad2 and survivin causes spindle assembly defects and mitotic catastrophe.
Mitotic catastrophe is a form of cell death that results from aberrant mitosis. Currently, the mechanisms involved in this form of cell death remain poorly understood. We found that actinomycin D induces mitotic catastrophe with severe spindle assembly defects. We have studied the nature of three groups of chromosome binding proteins in mitotic cells treated with actinomycin D. We found that actinomycin D reduced the binding affinity of RCC1 to the mitotic chromosome, which led to a reduction of RanGTP level. In addition, Mad2 was not concentrated at the kinetochores, indicating that the mitotic spindle checkpoint was affected. Furthermore, the localization of survivin was altered in cells. These data suggested that chromosomal binding of the mitotic regulators such as RCC1, Mad2 and survivin is essential for mitotic progression. Mitotic chromosomes not only carry the genetic material needed for the newly synthesized daughter cells, but also serve as docking sites for some of the mitotic regulators. Perturbation of their binding to the mitotic chromosome by actinomycin D could affect their functions in regulating mitotic progression thus leading to severe spindle defects and mitotic catastrophe.
Ho
Chin-Yee
CY
Division of Molecular and Cell Biology, School of Biological Sciences, College of Science, Nanyang Technological University, Singapore 637551, Singapore.
Wong
Chi-Hang
CH
Li
Hoi-Yeung
HY
D001665:Binding Sites; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002875:Chromosomes / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D031541:Fluorescence Resonance Energy Transfer; D005455:Fluorescent Antibody Technique; D020662:Guanine Nucleotide Exchange Factors / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D051034:Inhibitor of Apoptosis Proteins; D018386:Kinetochores / Q000378:metabolism; D064246:Mad2 Proteins; D008869:Microtubule-Associated Proteins / Q000032:analysis / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology*; D009363:Neoplasm Proteins / Q000032:analysis / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*; D008941:Spindle Apparatus / Q000378:metabolism*; D000077022:Survivin
C107489:BIRC5 protein, human; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D020662:Guanine Nucleotide Exchange Factors; D051034:Inhibitor of Apoptosis Proteins; C577697:MAD2L1 protein, human; D064246:Mad2 Proteins; D008869:Microtubule-Associated Proteins; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; C062521:RCC1 protein, human; D012097:Repressor Proteins; D000077022:Survivin; D003609:Dactinomycin