Cytokinesis is the final step in cell division. Errors at this stage prevent the final separation of the newly formed cells and give rise to a single cell, defined as polyploid, harbouring an abnormal chromsome content. Polyploidy promotes in turn chromosomal instability, a hallmark of cancer.
Here Rinaldo and collaborators show that HIPK2, a kinase involved in many cell fate decisions during development and in response to stress, controls cytokinesis and prevents the formation of polyploid cells. HIPK2 localize at the midbody, a structure that determines the site where the daughters cells will cleave. HIPK2 depletion prevents cell cleavage, resulting in polyploidization. Overall, these data uncover a critical HIPK2 function in cytokinesis and in preventing the onset of polyploidy.

Article: HIPK2 controls cytokinesis and prevents tetraploidization by phosphorylating histone H2B at the midbody. Rinaldo C, Moncada A, Gradi A, Ciuffini L, D'Eliseo D, Siepi F, Prodosmo A, Giorgi A, Pierantoni GM, Trapasso F, Guarguaglini G, Bartolazzi A, Cundari E, Schininà ME, Fusco A, Soddu S. Mol Cell. 2012 vol. 47:87-98. doi: 10.1016/j.molcel.2012.04.029.