Inhibition of clathrin by pitstop 2 activates the spindle assembly checkpoint and induces cell death in dividing HeLa cancer cells
1 Children's Medical Research Institute, The University of Sydney, 214 Hawkesbury Road, Westmead, NSW, 2145, Australia
2 Institute of Chemistry and Biochemistry & Neurocure Cluster of Excellence, Freie Universität Berlin, Berlin, 14195, Germany
3 Leibniz-Institut für Molekulare Pharmakologie (FMP), Berlin-Buch, Germany
4 Chemistry, School of Environmental & Life Sciences, The University of Newcastle, Callaghan, NSW, 2308, Australia
5 Children’s Medical Research Institute, Locked Bag 23, Wentworthville, NSW, 2145, Australia
Molecular Cancer 2013, 12:4 doi:10.1186/1476-4598-12-4Published: 17 January 2013
During metaphase clathrin stabilises the mitotic spindle kinetochore(K)-fibres. Many anti-mitotic compounds target microtubule dynamics. Pitstop 2™ is the first small molecule inhibitor of clathrin terminal domain and inhibits clathrin-mediated endocytosis. We investigated its effects on a second function for clathrin in mitosis.
Pitstop 2 did not impair clathrin recruitment to the spindle but disrupted its function once stationed there. Pitstop 2 trapped HeLa cells in metaphase through loss of mitotic spindle integrity and activation of the spindle assembly checkpoint, phenocopying clathrin depletion and aurora A kinase inhibition.
Pitstop 2 is therefore a new tool for investigating clathrin spindle dynamics. Pitstop 2 reduced viability in dividing HeLa cells, without affecting dividing non-cancerous NIH3T3 cells, suggesting that clathrin is a possible novel anti-mitotic drug target.