Gassmann Reto, Carvalho Ana, Henzing Alexander J, Ruchaud Sandrine, Hudson Damien F, Honda Reiko, Nigg Erich A, Gerloff Dietlind L, Earnshaw William C
Wellcome Trust Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Kings Buildings, Mayfield Rd., Edinburgh EH9 3JR, Scotland, UK.
J Cell Biol. 2004 Jul 19;166(2):179-91. doi: 10.1083/jcb.200404001. Epub 2004 Jul 12.
The chromosomal passenger complex of Aurora B kinase, INCENP, and Survivin has essential regulatory roles at centromeres and the central spindle in mitosis. Here, we describe Borealin, a novel member of the complex. Approximately half of Aurora B in mitotic cells is complexed with INCENP, Borealin, and Survivin; and Borealin binds Survivin and INCENP in vitro. A second complex contains Aurora B and INCENP, but no Borealin or Survivin. Depletion of Borealin by RNA interference delays mitotic progression and results in kinetochore-spindle misattachments and an increase in bipolar spindles associated with ectopic asters. The extra poles, which apparently form after chromosomes achieve a bipolar orientation, severely disrupt the partitioning of chromosomes in anaphase. Borealin depletion has little effect on histone H3 serine10 phosphorylation. These results implicate the chromosomal passenger holocomplex in the maintenance of spindle integrity and suggest that histone H3 serine10 phosphorylation is performed by an Aurora B-INCENP subcomplex.
极光激酶B、染色体乘客复合体蛋白（INCENP）和生存素（Survivin）组成的染色体乘客复合体在有丝分裂的着丝粒和纺锤体中央发挥着重要的调控作用。在此，我们描述了该复合体的一个新成员—— borealin。在有丝分裂细胞中，大约一半的极光激酶B与INCENP、borealin和Survivin形成复合体；并且borealin在体外能与Survivin和INCENP结合。另一种复合体包含极光激酶B和INCENP，但不含borealin或Survivin。通过RNA干扰使borealin缺失会延迟有丝分裂进程，并导致动粒与纺锤体错误连接，以及与异位星体相关的双极纺锤体数量增加。这些额外的纺锤极显然是在染色体实现双极定向后形成的，会严重扰乱后期染色体的分配。borealin缺失对组蛋白H3丝氨酸10磷酸化影响不大。这些结果表明染色体乘客全复合体在维持纺锤体完整性方面发挥作用，并提示组蛋白H3丝氨酸10磷酸化是由极光激酶B - INCENP亚复合体完成的。
