The Open University ’ s repository of research publications and other research outputs Microtubule interfering agents and KSP inhibitors

Article history: Received 7 June 2008 Accepted 8 September 2008 17 Microtubule interfering agents (MIAs) are anti-tumor drugs that inhibit microtubule 18 dynamics, while kinesin spindle protein (KSP) inhibitors are substances that block the 19 formation of the bipolar spindle duringmitosis. All these compounds cause G2/M arrest and 20 cell death. Using 2D–PAGE followedbyNano-LC-ESI-Q-ToF analysis, we found thatMIAs such 21 as vincristine (Oncovin) or paclitaxel (Taxol) and KSP inhibitors such as S-tritil-L-cysteine 22 induce the phosphorylation of the nuclear protein p54 in HeLa cells. Furthermore, we demonstrate that cisplatin (Platinol), an anti-tumor drug that does not cause M arrest, does not induce this modification. We show that the G2/M arrest induced by the MIAs is required for p54 phosphorylation. Finally, we demonstrate that CDK activity is required for MIAinduced phosphorylation of p54. © 2008 Elsevier B.V. All rights reserved.