Essential Roles of Drosophila Inner Centromere Protein (Incenp) and Aurora B in Histone H3 Phosphorylation, Metaphase Chromosome Alignment, Kinetochore Disjunction, and Chromosome Segregation

Abstract

We have performed a biochemical and double-stranded RNA-mediated interference (RNAi) analysis of the role of two chromosomal passenger proteins, inner centromere protein (INCENP) and aurora B kinase, in cultured cells of Drosophila melanogaster. INCENP and aurora B function is tightly interlinked. The two proteins bind to each other in vitro, and DmINCENP is required for DmAurora B to localize properly in mitosis and function as a histone H3 kinase. DmAurora B is required for DmINCENP accumulation at centromeres and transfer to the spindle at anaphase. RNAi for either protein dramatically inhibited the ability of cells to achieve a normal metaphase chromosome alignment. Cells were not blocked in mitosis, however, and entered an aberrant anaphase characterized by defects in sister kinetochore disjunction and the presence of large amounts of amorphous lagging chromatin. Anaphase A chromosome movement appeared to be normal, however cytokinesis often failed. DmINCENP and DmAurora B are not required for the correct localization of the kinesin-like protein Pavarotti (ZEN-4/CHO1/MKLP1) to the midbody at telophase. These experiments reveal that INCENP is required for aurora B kinase function and confirm that the chromosomal passengers have essential roles in mitosis.

Contractile Ring-independent Localization of DdINCENP, a Protein Important for Spindle Stability and Cytokinesis

“…The behavior of chromosomes in the DdINCENP null cells contrasted sharply with that of wild-type cells, which always displayed normal segregation of chromosomes (Graf et al, 2003; Figure 4; see Video 5). The mitotic and the cytokinetic defects displayed by the DdINCENP null cells were consistent with the observation in other organisms that INCENP plays important roles during mitosis (Kaitna et al, 2000;Adams et al, 2001b).…”

“…It can stimulate the kinase activity of Aurora B and is also a substrate of Aurora B kinase (Kang et al, 2001;Honda et al, 2003). In both Drosophila and Caenorhabditis elegans, depletion of INCENP by RNAi causes failed chromosome congression at metaphase, mislocalization of Aurora B, and cytokinesis defects (Kaitna et al, 2000;Adams et al, 2001b). Also, in Xenopus mitotic egg extracts, immu-nodepletion of INCENP induced the formation of monopolar spindles (Sampath et al, 2004).…”

Centrosome amplification induced by survivin suppression enhances both chromosome instability and radiosensitivity in glioma cells

“…It inhibits apoptosis (Altieri, 2001) and is involved in the spindle checkpoint and the regulation of proper chromosomal segregation during mitosis by acting as a member of the chromosomal passenger protein family (Li et al, 1998;Adams et al, 2001). A number of studies have demonstrated that the suppression of survivin results in cells with multipolar mitotic spindles that are either multinucleated or aneuploid (Li et al, 1999;Beltrami et al, 2004;Kappler et al, 2004).…”

An integrated pharmacokinetic–pharmacodynamic model for an Aurora kinase inhibitor

“…[8]). They are involved in some checkpoint regulation pathways including spindle assembly checkpoint, alignment of metaphase chromosomes, chromosomal biorientation, kinetochore-microtubule association and cytokinesis [9]. Aberrant expression of Aurora kinases may disturb checkpoint functions particularly in mitosis and this may lead to deregulation of cell division and trigger the development of tumours [10,11].…”