Abstract
Aurora kinases are serine/threonine protein kinases with essential roles in cell division through eukaryotes. Although functions of animal and yeast Aurora kinases have been analyzed in detail, those of plant Aurora kinases are unknown. An Aurora kinase inhibitor, Hesperadin, can inhibit the kinase activity of AtAUR3. Hesperadin treated tobacco BY-2 cultured cells increased in the ratio of metaphase cells, while the ratio of anaphase/telophase cells decreased, although the mitotic index was not affected. These results suggest that Hesperadin induces delayed transition from metaphase to anaphase, and early exit from mitosis after chromosome segregation. In addition, lagging chromosomes, which caused by the delay and failure of sister chromatid separation, were observed at anaphase and telophase in Hesperadin-treated cells. These data suggest that the plant Aurora kinase plays a role in chromosome alignment and segregation.
