Depletion of CPAP by RNAi disrupts centrosome integrity and induces multipolar spindles.
We previously identified a novel microtubule-destabilizing motif in CPAP that can disassemble microtubules. To examine further the CPAP function in human cells, we used siRNA to knockdown its expression. Our results showed that CPAP depletion arrested cells in mitosis and induced apoptosis. Interestingly, more than 40% of these mitotic cells had multiple spindle poles. Furthermore, inhibition of the kinesin Eg5 in CPAP-depleted cells resulted in monopolar spindles, indicating that Eg5 function is required for multipolar spindle formation in the absence of CPAP. Together, our results reveal a structural role for CPAP to maintain centrosome integrity and normal spindle morphology during cell division.
Cho
Jun-Hung
JH
Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan.
Chang
Chih-Jui
CJ
Chen
Chiung-Ya
CY
Tang
Tang K
TK
D017209:Apoptosis / Q000502:physiology; D002453:Cell Cycle / Q000502:physiology*; D018385:Centrosome / Q000378:metabolism* / Q000648:ultrastructure*; D006367:HeLa Cells; D006801:Humans; D016547:Kinesins / Q000378:metabolism; D008869:Microtubule-Associated Proteins / Q000172:deficiency* / Q000235:genetics*; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D008941:Spindle Apparatus / Q000378:metabolism* / Q000648:ultrastructure*
C414735:CENPJ protein, human; C470243:KIF11 protein, human; D008869:Microtubule-Associated Proteins; D034741:RNA, Small Interfering; D016547:Kinesins