Aurora-A kinase maintains the fidelity of early and late mitotic events in HeLa cells.
Aurora-A, a member of the Aurora/Ipl1-related kinase family, is overexpressed in various types of cancer and considered to play critical roles in tumorigenesis. To better understand the pathological effect of Aurora-A activation, it is first necessary to elucidate the physiological functions of Aurora-A. Here, we have investigated the roles of Aurora-A in mitotic progression with the small interfering RNA, antibody microinjection, and time lapse microscopy using human cells. We demonstrated that suppression of Aurora-A by small interfering RNA caused multiple events to fail in mitosis, such as incorrect separation of centriole pairs, misalignment of chromosomes on the metaphase plate, and incomplete cytokinesis. Antibody microinjection of Aurora-A into late G2 cells induced dose-dependent failure in separation of centriole pairs at prophase, indicating that Aurora-A is essential for proper separation of centriole pairs. When we injected anti-Aurora-A antibodies into prometaphase cells that had separated their centriole pairs, chromosomes were severely misaligned on the metaphase plate, indicating that Aurora-A is required for proper movement of chromosomes on the metaphase plate. Furthermore, inhibition of Aurora-A at metaphase by microinjected antibodies prevented cells from completing cytokinesis, suggesting that Aurora-A also has important functions in late mitosis. These results strongly suggest that Aurora-A is essential for many crucial events during mitosis and that the phosphorylation of a series of substrates by Aurora-A at different stages of mitosis may promote diverse critical events in mitosis to maintain chromosome integrity in human cells.
Marumoto
Tomotoshi
T
Department of Tumor Genetics and Biology, Graduate School of Medical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto 860-8556, Japan.
Honda
Shinobu
S
Hara
Toshihiro
T
Nitta
Masayuki
M
Hirota
Toru
T
Kohmura
Eiji
E
Saya
Hideyuki
H
D000906:Antibodies / Q000494:pharmacology; D064127:Aurora Kinases; D018797:Cell Cycle Proteins; D002455:Cell Division; D002502:Centrioles; D002875:Chromosomes; D006367:HeLa Cells; D006801:Humans; D008677:Metaphase; D008938:Mitosis; D011494:Protein Kinases / Q000276:immunology / Q000502:physiology*; D017346:Protein Serine-Threonine Kinases; D034741:RNA, Small Interfering / Q000494:pharmacology; D008941:Spindle Apparatus; D029867:Xenopus Proteins
D000906:Antibodies; D018797:Cell Cycle Proteins; D034741:RNA, Small Interfering; D029867:Xenopus Proteins; D011494:Protein Kinases; C112134:AURKA protein, Xenopus; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases