Aurora B kinase-dependent recruitment of hZW10 and hROD to tensionless kinetochores.
The mitotic checkpoint ensures proper chromosome segregation by monitoring two critical events during mitosis. One is kinetochore attachment to the mitotic spindle, and the second is the alignment of chromosomes at the metaphase plate, resulting in tension across sister kinetochores (reviewed in [1, 2]). Mitotic-checkpoint proteins are known to accumulate at unaligned chromosomes that have not achieved proper kinetochore-microtubule attachments or established an adequate level of tension across sister kinetochores. Here, we report that hZW10 and hROD, two components of the evolutionarily conserved RZZ complex, accumulate at kinetochores in response to the loss of tension. By using live-cell imaging and FRAP, we showed that the accumulation of hZW10 at tensionless kinetochores stems from a 4-fold reduction of kinetochore turnover rate. We also found that cells lacking hZW10 escape loss-of-tension-induced mitotic-checkpoint arrest more rapidly than those arrested in response to the lack of kinetochore-microtubule attachments. Furthermore, we show that pharmacological inhibition of Aurora B kinase activity with ZM447439 in the absence of tension, but not in the absence of kinetochore-microtubule attachments, results in the loss of hZW10, hROD, and hBub1 from kinetochores. We therefore conclude that Aurora B kinase activity is required for the accumulation of tension-sensitive mitotic-checkpoint components, such as hZW10 and hROD, in order to maintain mitotic-checkpoint arrest.
Department of Oncology, University of Alberta, Edmonton, Alberta T6G 1Z2, Canada.
Jakub K
JK
Famulski
Gordon K
GK
Chan
D064107:Aurora Kinase B; D064127:Aurora Kinases; D018797:Cell Cycle Proteins / Q000378:metabolism*; D000072159:Dynactin Complex; D004398:Dyneins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism*; D018386:Kinetochores / Q000378:metabolism*; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D008938:Mitosis / Q000502:physiology*; D009687:Nuclear Proteins / Q000378:metabolism*; D017239:Paclitaxel; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D050257:Tubulin Modulators
D018797:Cell Cycle Proteins; D000072159:Dynactin Complex; D047908:Intracellular Signaling Peptides and Proteins; C489309:KNTC1 protein, human; D008869:Microtubule-Associated Proteins; D009687:Nuclear Proteins; D050257:Tubulin Modulators; C413695:ZWINT protein, human; 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; D004398:Dyneins; D017239:Paclitaxel