Article

Mitotic DNA damage targets the Aurora A/TPX2 complex

Institute of Molecular Cancer Research, University of Zurich, Zurich, Switzerland.
Cell cycle (Georgetown, Tex.) (Impact Factor: 5.01). 12/2010; 9(22):4592-9. DOI: 10.4161/cc.9.22.13665
Source: PubMed

ABSTRACT We have previously shown that the DNA damage-induced G2 arrest is contributed by inhibition of Aurora A (AurA) and that transduction of active AurA into arrested cells allows bypassing the block through reactivation of CDK1. In this study, we investigated the mechanism of DNA damage-induced AurA inhibition. We provide evidence that ionizing radiation (IR) administered in mitosis, a time when AurA protein and enzymatic activity reach peak levels, impairs interaction with the partner TPX2, leading to inactivation of the kinase through dephosphorylation of AurA T-loop residue, T288. We find that decreased AurA-TPX2 complex formation in response to irradiation results from reduced cellular levels of TPX2, an effect that is both contributed by increased APC/CDH1-dependent protein degradation and decreased translation of TPX2 mRNA.

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