Nara Institute of Science and Technology, Graduate School of Biological Sciences, Ikoma, Nara 630-0192, Japan.
University of Hamburg, Institute for Plant Sciences and Microbiology, Department of Developmental Biology, D-22609 Hamburg, Germany.
Plant Physiol. 2020 Aug;183(4):1586-1599. doi: 10.1104/pp.20.00344. Epub 2020 May 27.
The Aurora B kinase, encoded by the () gene in Arabidopsis (), is a key regulator of cell division in all eukaryotes. Aurora B has at least two central functions during cell division; it is essential for the correct, i.e. balanced, segregation of chromosomes in mitosis and meiosis by controlling kinetochore function, and it acts at the division plane, where it is necessary to complete cytokinesis. To accomplish these two spatially distinct functions, Aurora B in animals is guided to its sites of action by Borealin, inner centromere protein (INCENP), and Survivin, which, together with Aurora B, form the chromosome passenger complex (CPC). However, besides Aurora homologs, only a candidate gene with restricted homology to INCENP has been described in Arabidopsis, raising the question of whether a full complement of the CPC exists in plants and how Aurora homologs are targeted subcellularly. Here, we have identified and functionally characterized a Borealin homolog, BOREALIN RELATED (BORR), in Arabidopsis. Together with detailed localization studies including the putative Arabidopsis INCENP homolog, these results support the existence of a CPC in plants.
在所有真核生物中，由拟南芥（Arabidopsis）基因（）编码的 Aurora B 激酶是细胞分裂的关键调节因子。Aurora B 在细胞分裂过程中至少具有两个核心功能；它通过控制着丝粒功能对于有丝分裂和减数分裂中染色体的正确（即平衡）分离是必需的，并且它在分裂平面上发挥作用，在那里完成胞质分裂是必要的。为了完成这两个空间上不同的功能，动物中的 Aurora B 被 Borealin、内着丝粒蛋白（INCENP）和 Survivin 引导至其作用部位，这些蛋白与 Aurora B 一起形成染色体乘客复合物（CPC）。然而，除了 Aurora 同源物之外，在拟南芥中仅描述了一个与 INCENP 具有有限同源性的候选基因，这引发了一个问题，即在植物中是否存在 CPC 的完整成分，以及 Aurora 同源物如何在亚细胞水平上被靶向。在这里，我们已经鉴定并在功能上表征了拟南芥中的 Borealin 同源物，即 BOREALIN RELATED（BORR）。这些结果与包括假定的拟南芥 INCENP 同源物在内的详细定位研究一起，支持了 CPC 在植物中的存在。
