High impact information on ial

• Aurora B mediates chromosome segregation by ensuring proper biorientation of sister chromatids, possibly through the regulation of microtubule dynamics [1].
• In contrast, peripheral MTs still probe the cortex and form regions of overlap that recruit the Pav-KLP motor and Aurora B kinase. orbit mutants have disorganized or incomplete anillin and actin rings, and although cleavage furrows initiate, they ultimately regress [2].
• This suggests that the association of Aurora B with chromosomes is not a prerequisite for its accumulation at the central spindle, or for its function during cytokinesis [3].
• We provide evidence that Aurora B interacts with and requires the Cdc37/Hsp90 complex for its stability [4].
• These experiments reveal that INCENP is required for aurora B kinase function and confirm that the chromosomal passengers have essential roles in mitosis [5].

Biological context of ial

• Given its established role in destabilizing kinetochore-microtubule interactions [3], Aurora B dissociation is likely to be key to the change in kinetochore behavior [6].
• A MEI-S332 mutant that is only poorly phosphorylated by Aurora B is defective in localization to centromeres [7].
• INCENP and Aurora B promote meiotic sister chromatid cohesion through localization of the Shugoshin MEI-S332 in Drosophila [7].
• The Drosophila STAM gene homolog is in a tight gene cluster, and its expression correlates to that of the adjacent gene ial [8].
• Characterization of spatial and temporal expression of ial and its gene product showed that it manifests itself in patterns which can be consistent with a role in cell cycle control [9].

Anatomical context of ial

• 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 [5].

Associations of ial with chemical compounds

• Although it has been possible to use conventional genetic analysis to dissect the function of aurora, the founding family member in Drosophila (Glover, D.M., M.H. Leibowitz, D.A. McLean, and H. Parry. 1995. Cell. 81:95-105), the lack of mutations in a second aurora-like kinase gene, aurora B, precluded this approach [10].
• These include a drastic reduction of histone H3 phosphorylation at serine 10 (a target of Aurora B kinase), a pronounced attenuation at prometaphase and multipolar spindles [11].
• The treatment of such cells with calyculin A induced Ser28 phosphorylation in the Aurora-B-localized area [12].

Enzymatic interactions of ial

• Aurora-B phosphorylates Histone H3 at serine28 with regard to the mitotic chromosome condensation [12].

Other interactions of ial

• INCENP binds to the cohesion protector protein MEI-S332, which is also an excellent in vitro substrate for Aurora B kinase [7].
• Here we show that the loss of function of Cdc37 in Drosophila leads to defects in mitosis and male meiosis, and that these phenotypes closely resemble those brought about by the inactivation of Aurora B [4].
• Drosophila aurora B kinase is required for histone H3 phosphorylation and condensin recruitment during chromosome condensation and to organize the central spindle during cytokinesis [10].
• Aurora-B was primarily localized in the heterochromatin of late G2 phase cells, where only Ser10 phosphorylation was observed [12].

Analytical, diagnostic and therapeutic context of ial

• Dissection of the Aurora B pathway, where we found a new gene and a specific small molecule inhibitor, should benefit particularly [13].

References