Aurora kinase is required for chromosome segregation in tobacco BY‐2 cells

Abstract

SummaryPost-translational modifications of core histone tails play crucial roles in chromatin structure and function. Although phosphorylation of Ser10 and Ser28 (H3S10ph and H3S28ph) of histone H3 is ubiquitous among eukaryotes, the phosphorylation mechanism during the cell cycle remains unclear. In the present study, H3S10ph and H3S28ph in tobacco BY-2 cells were observed in the pericentromeric regions during mitosis. Moreover, the Aurora kinase inhibitor Hesperadin inhibited the kinase activity of Arabidopsis thaliana Aurora kinase 3 (AtAUR3) in phosphorylating both Ser10 and Ser28 of histone H3 in vitro. Consistently, Hesperadin inhibited both H3S10ph and H3S28ph during mitosis in BY-2 cells. These results indicate that plant Aurora kinases phosphorylate not only Ser10, but also Ser28 of histone H3 in vivo. Hesperadin treatment increased the ratio of metaphase cells, while the ratio of anaphase/telophase cells decreased, although the mitotic index was not affected in Hesperadin-treated cells. These results suggest that Hesperadin induces delayed transition from metaphase to anaphase, and early exit from mitosis after chromosome segregation. In addition, micronuclei were observed frequently and lagging chromosomes, caused by the delay and failure of sister chromatid separation, were observed at anaphase and telophase in Hesperadin-treated BY-2 cells. The data obtained here suggest that plant Aurora kinases and H3S10ph/H3S28ph may have a role in chromosome segregation and metaphase/anaphase transition.

The Cyclin-Dependent Kinase Inhibitor KRP6 Induces Mitosis and Impairs Cytokinesis in Giant Cells Induced by Plant-Parasitic Nematodes in Arabidopsis

“…Recently, treatment of tobacco (Nicotiana tabacum) Bright Yellow 2 with the Aurora kinase inhibitor hesperadin has been found to induce the formation of micronuclei because of lagging chromosomes during the metaphase-to-anaphase transition (Kurihara et al, 2006). Multinucleate cells with two or more nuclei of unequal size, as observed here in KRP6 OE cultured cells, and in nematodeinfected root cells, has been similarly reported to occur upon the expression of indestructible CYCB1;1 in tobacco Bright Yellow 2 cells (Criqui et al, 2001;Weingartner et al, 2004).…”

Arabidopsisα Aurora Kinases Function in Formative Cell Division Plane Orientation

“…Cell cycle-dependent phosphorylation of HIS-TONE H3 is performed by all three Arabidopsis Aurora kinases (Demidov et al, 2005(Demidov et al, , 2009Kawabe et al, 2005;Kurihara et al, 2006Kurihara et al, , 2008. Therefore, the activity of AUR3, together with residual activity of a Auroras, might explain why no differential immunostaining was observed between Arabidopsis wild-type and aur1-2 aur2-2 mutant plants using an antibody against phosphorylated HISTONE H3.…”

“…Arabidopsis Aurora kinases have been shown to phosphorylate Ser-10 of HISTONE H3 in concert with posttranslational modifications of neighboring residues (Demidov et al, 2005(Demidov et al, , 2009Kawabe et al, 2005). Chemical inactivation of Aurora, interfering with this phosphorylation, delays metaphase chromosome alignment and causes lagging anaphase chromosomes without inhibiting mitotic progression (Kurihara et al, 2006(Kurihara et al, , 2008Demidov et al, 2009). However, nothing is known about their developmental role.…”

Impact of nucleosome dynamics and histone modifications on cell proliferation during Arabidopsis development

“…Multiple kinases have been identified in mammalian cells that show H3 phosphorylation activity (Ito, 2007). The Arabidopsis homologs of AURORA (AUR1-3) kinases are highly expressed in mitosis and can efficiently use H3 as a substrate, consistent with a role at this stage (Demidov et al, 2005;Kawabe et al, 2005;Kurihara et al, 2006). The TOUSLED (TSL) kinase is expressed at a constant rate during the cell cycle but its activity peaks between late G2/M and the next G1 phase and H3 is also a known substrate (Figure 1) (Ehsan et al, 2004), although conflicting reports exist regarding the role of TSL on H3 phosphorylation .…”