Petrovská B., Cenklová V., Pochylová Ž., Kourová H., Doskočilová A., Plíhal O., Binarová L., Binarová P.
NEW PHYTOLOGIST
193:
590-604,
2012
Keywords:
Arabidopsis thaliana, AtTPX2 (targeting protein for Xklp2), Aurora kinases, cytokinesis, endoreduplication, meristems, RNAi, gamma-tubulin.
Abstract:
The conserved family of Aurora kinases has multiple functions during mitosis. The roles of
plant Aurora kinases have been characterized using inhibitor treatments.
We down-regulated Aurora kinases in Arabidopsis thaliana using RNA interference (RNAi).
We carried out a detailed phenotypic analysis of Aurora RNAi plants, biochemical andmicroscopic
studies of AtAurora1 kinase together with AtTPX2 (targeting protein for Xklp2) and c-tubulin.
Cell division defects were observed in plants with reduced expression of Aurora kinases.
Furthermore, the maintenance of primary meristems was compromised and RNAi seedlings
entered endoreduplication prematurely. AtAurora1, its activator AtTPX2, and c-tubulin were
associated with microtubules in vitro; they were attached to regrowing kinetochore microtubules
and colocalized on spindle microtubules and with a subset of early phragmoplast
microtubules. Only the AtAurora1 kinase was translocated to the area of the cell plate.
RNAi silencing of Aurora kinases showed that, in addition to their function in regulating
mitosis, the kinases are required for maintaining meristematic activity and controlling the
switch from meristematic cell proliferation to differentiation and endoreduplication. The colocalization
and co-fractionation of AtAurora1 with AtTPX2, and c-tubulin on microtubules in a
cell cycle-specific manner suggests that AtAurora1 kinase may function to phosphorylate
substrates that are critical to the spatiotemporal regulation of acentrosomal microtubule
formation and organization.
IEB authors: Pavla Binarová,
Věra Cenklová,
Beáta Petrovská
Čeština
English