Kawabe Akira, Matsunaga Sachihiro, Nakagawa Katsuyuki, Kurihara Daisuke, Yoneda Arata, Hasezawa Seiichiro, Uchiyama Susumu, Fukui Kiichi
Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, 565-0871, Suita, Osaka, Japan.
Plant Mol Biol. 2005 May;58(1):1-13. doi: 10.1007/s11103-005-3454-x.
The Aurora kinase family is a well-characterized serine/threonine protein kinase family that regulates different processes of mitotic events. Although functions of animal and yeast Aurora kinases have been analyzed, plant aurora kinases were not identified and characterized. We identified three Aurora kinase orthologs in Arabidopsis thaliana and designated these as AtAUR1, AtAUR2, and AtAUR3. These AtAURs could phosphorylate serine 10 in histone H3, in vitro. Dynamic analyses of GFP-fused AtAUR proteins revealed that AtAUR1 and AtAUR2 localized at the nuclear membrane in interphase and located in mitotic spindles during cell division. AtAUR1 also localized in the cell plates. AtAUR3 showed dot-like distribution on condensed chromosomes at prophase and then localized at the metaphase plate. At late anaphase, AtAUR3 is evenly localized on chromosomes. The localization of AtAUR3 during mitosis is very similar to that of phosphorylated histone H3. Interestingly, an overexpression of AtAUR3 induces disassembly of spindle microtubules and alteration of orientation of cell division. Our results indicate that plant Aurora kinases have different characters from that of Aurora kinases of other eukaryotes.
极光激酶家族是一个已被充分表征的丝氨酸/苏氨酸蛋白激酶家族，它调节有丝分裂事件的不同过程。尽管动物和酵母极光激酶的功能已被分析，但植物极光激酶尚未被鉴定和表征。我们在拟南芥中鉴定出三个极光激酶直系同源物，并将它们命名为AtAUR1、AtAUR2和AtAUR3。这些AtAURs在体外能够磷酸化组蛋白H3中的丝氨酸10。对绿色荧光蛋白融合的AtAUR蛋白的动态分析表明，AtAUR1和AtAUR2在间期定位于核膜，在细胞分裂期间定位于有丝分裂纺锤体。AtAUR1也定位于细胞板。AtAUR3在前期在浓缩染色体上呈点状分布，然后定位于中期板。在后期，AtAUR3均匀地定位于染色体上。AtAUR3在有丝分裂期间的定位与磷酸化组蛋白H3的定位非常相似。有趣的是，AtAUR3的过表达诱导纺锤体微管的解体和细胞分裂方向的改变。我们的结果表明，植物极光激酶与其他真核生物的极光激酶具有不同的特征。
