Investigating the concerted regulation of cell division by phosphorylation and sumoylation.

The rapid and dynamic temporal and spatial control of protein localisation by post-translational modifications (PTMs) is essential for cell division. The importance of phosphorylation and sumoylation individually in cell division has been established (1, 2), yet there is less of an understanding about how these PTMs act together to regulate protein localisation throughout cell division. Using Caenorhabditis elegans (C. elegans) as a model, this project will investigate the cross-talk between phosphorylation and sumoylation at the chromosomal passenger complex (CPC) - a heterotetrameric complex consisting of INCENP, Borealin, Survivin, and Aurora B. We will investigate the effect of CPC-mediated phosphorylation on the function of SUMO E3 ligase GEI-17 and the effect of SUMO on protein phosphatase 2A:B56 (PP2A:B56) recruitment. Subsequently, we aim to gain an understanding of whether SUMO bridges these two functions, whereby the effect of the CPC on GEI-17 function impacts PP2A:B56 recruitment, which is known to antagonise the activity of the CPC kinase Aurora B (2).