Centromere localization of INCENP-Aurora B is sufficient to support spindle checkpoint function.
During mitosis, the chromosomal passenger complex (CPC) comprising the Aurora B kinase, INCENP, survivin and borealin is essential for correcting non-bipolar chromosome attachments and for cytokinesis. In addition, the CPC might fullfil a role in the mitotic spindle assembly checkpoint (SAC), but this activity might be related to its role in correcting non-bipolar chromosome attachments. Here, we demonstrate that treatment of mitotic cells with the antibiotic actinomycin D causes a displacement of an intact and active CPC from centromeres onto chromosome arms, which results in chromosome misalignment, cytokinesis failure and SAC override, but still preserves histone H3 phosphorylation on chromosome arms. This surprising and unique scenario allows the reconstitution of endogenous Aurora B at centromeres/inner kinetochores by expressing a Cenp-B-INCENP fusion protein. We find that although the selective recruitment of endogenous Aurora B to centromeres/inner kinetochores is not sufficient to restore chromosome alignment and cytokinesis, it can restore Cenp-A phosphorylation at kinetochores, BubR1 recruitment to kinetochores and SAC activity after spindle disruption. These results indicate that INCENP-Aurora B localized at centromeres/inner kinetochores is sufficient to mediate SAC activity upon spindle disruption.
Becker
Markus
M
Philipps-University Marburg, Marburg, Germany.
Stolz
Ailine
A
Ertych
Norman
N
Bastians
Holger
H
D064107:Aurora Kinase B; D064127:Aurora Kinases; D015153:Blotting, Western; D002503:Centromere / Q000187:drug effects / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism*; D003609:Dactinomycin / Q000494:pharmacology; D005434:Flow Cytometry; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D018386:Kinetochores / Q000187:drug effects / Q000378:metabolism*; D008856:Microscopy, Fluorescence; D008938:Mitosis / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D010957:Plasmids; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D014162:Transfection
D002868:Chromosomal Proteins, Non-Histone; C083767:INCENP protein, human; D003609:Dactinomycin; 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