Aurora B controls the association of condensin I but not condensin II with mitotic chromosomes.
The assembly of mitotic chromosomes is controlled by condensin complexes. In vertebrates, condensin I binds to chromatin in prometaphase, confers rigidity to chromosomes and enables the release of cohesin complexes from chromosome arms, whereas condensin II associates with chromosomes in prophase and promotes their condensation. Both complexes are essential for chromosome segregation in anaphase. Although the association of condensins with chromatin is important for the assembly and segregation of mitotic chromosomes, it is poorly understood how this process is controlled. Here we show that the mitotic kinase Aurora B regulates the association of condensin I, but not the interaction of condensin II with chromatin. Quantitative time-lapse imaging of cells expressing GFP-tagged condensin subunits revealed that Aurora B is required for efficient loading of condensin I onto chromosomes in prometaphase and for maintenance of the complex on chromosomes in later stages of mitosis. The three non-SMC subunits of condensin I are Aurora B substrates in vitro and their mitosis-specific phosphorylation depends on Aurora B in vivo. Our data indicate that Aurora B contributes to chromosome rigidity and segregation by promoting the binding of condensin I to chromatin. We have also addressed how Aurora B might mediate the dissociation of cohesin from chromosome arms.
Lipp
Jesse J
JJ
Research Institute of Molecular Pathology, Dr Bohrgasse 7, A-1030 Vienna, Austria.
Hirota
Toru
T
Poser
Ina
I
Peters
Jan-Michael
JM
D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000378:metabolism*; D064107:Aurora Kinase B; D064127:Aurora Kinases; D002843:Chromatin / Q000378:metabolism; D002877:Chromosomes, Human / Q000201:enzymology* / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D005456:Fluorescent Dyes / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007700:Kinetics; D018715:Microscopy, Video; D008938:Mitosis; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism*; D010766:Phosphorylation; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D021122:Protein Subunits / Q000737:chemistry; D013379:Substrate Specificity; D013449:Sulfonamides / Q000494:pharmacology
D002843:Chromatin; D004268:DNA-Binding Proteins; D005456:Fluorescent Dyes; D007211:Indoles; D046912:Multiprotein Complexes; D021122:Protein Subunits; D013449:Sulfonamides; C108312:condensin complexes; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins; C576921:AURKB protein, human; D064107:Aurora Kinase B; D064127:Aurora Kinases; D017346:Protein Serine-Threonine Kinases; D000251:Adenosine Triphosphatases; C474723:hesperadin