Aurora B couples chromosome alignment with anaphase by targeting BubR1, Mad2, and Cenp-E to kinetochores.
The Aurora/Ipl1 family of protein kinases plays multiple roles in mitosis and cytokinesis. Here, we describe ZM447439, a novel selective Aurora kinase inhibitor. Cells treated with ZM447439 progress through interphase, enter mitosis normally, and assemble bipolar spindles. However, chromosome alignment, segregation, and cytokinesis all fail. Despite the presence of maloriented chromosomes, ZM447439-treated cells exit mitosis with normal kinetics, indicating that the spindle checkpoint is compromised. Indeed, ZM447439 prevents mitotic arrest after exposure to paclitaxel. RNA interference experiments suggest that these phenotypes are due to inhibition of Aurora B, not Aurora A or some other kinase. In the absence of Aurora B function, kinetochore localization of the spindle checkpoint components BubR1, Mad2, and Cenp-E is diminished. Furthermore, inhibition of Aurora B kinase activity prevents the rebinding of BubR1 to metaphase kinetochores after a reduction in centromeric tension. Aurora B kinase activity is also required for phosphorylation of BubR1 on entry into mitosis. Finally, we show that BubR1 is not only required for spindle checkpoint function, but is also required for chromosome alignment. Together, these results suggest that by targeting checkpoint proteins to kinetochores, Aurora B couples chromosome alignment with anaphase onset.
School of Biological Sciences, University of Manchester, 2.205 Stopford Building, Oxford Rd., Manchester M13 9PT, UK.
Claire
C
Ditchfield
Victoria L
VL
Johnson
Anthony
A
Tighe
Rebecca
R
Ellston
Carolyn
C
Haworth
Trevor
T
Johnson
Andrew
A
Mortlock
Nicholas
N
Keen
Stephen S
SS
Taylor
D000705:Anaphase / Q000187:drug effects / Q000235:genetics*; D064107:Aurora Kinase B; D064127:Aurora Kinases; D001549:Benzamides / Q000494:pharmacology; D002135:Calcium-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D020090:Chromosome Segregation / Q000187:drug effects / Q000235:genetics*; D004261:DNA Replication / Q000187:drug effects / Q000235:genetics; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005057:Eukaryotic Cells / Q000187:drug effects / Q000201:enzymology* / Q000648:ultrastructure; D018816:Genes, cdc / Q000187:drug effects; D006367:HeLa Cells; D006801:Humans; D018386:Kinetochores / Q000187:drug effects / Q000378:metabolism*; D064246:Mad2 Proteins; D008938:Mitosis / Q000187:drug effects / Q000235:genetics*; D017239:Paclitaxel / Q000494:pharmacology; D010766:Phosphorylation / Q000187:drug effects; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors / Q000235:genetics*; D011799:Quinazolines / Q000494:pharmacology; D012097:Repressor Proteins / Q000187:drug effects / Q000235:genetics; D008941:Spindle Apparatus / Q000187:drug effects / Q000235:genetics; D016159:Tumor Suppressor Protein p53 / Q000187:drug effects / Q000235:genetics
C474722:4-(4-(N-benzoylamino)anilino)-6-methoxy-7-(3-(1-morpholino)propoxy)quinazoline; D001549:Benzamides; D002135:Calcium-Binding Proteins; D018797:Cell Cycle Proteins; D002868:Chromosomal Proteins, Non-Histone; D004791:Enzyme Inhibitors; C577697:MAD2L1 protein, human; D064246:Mad2 Proteins; D011799:Quinazolines; D012097:Repressor Proteins; D016159:Tumor Suppressor Protein p53; C068688:centromere protein E; D011494:Protein Kinases; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; C584277:BUB1 protein, human; C090464:Bub1 spindle checkpoint protein; D017346:Protein Serine-Threonine Kinases; D017239:Paclitaxel