Dissecting Polo kinase recruitment to the centrosome (360G-Wellcome-109096_Z_15_A)

Polo kinase is an important cell cycle regulator and it is essential for the correct assembly of centrosomes, major cell organisers. Centrosomes are formed by a pair of cylindrical centrioles surrounded by pericentriolar material (PCM). Polo controls PCM assembly (at least in part through Cnn phosphorylation) and also centriole disengagement and assembly. How Polo is recruited to centrioles and centrosomes is mysterious. During my rotation I have obtained evidence that the PCM protein Spd-2 is necessary for Polo recruitment to centrosomes. During my project I aim to characterise if Polo binding to Spd-2 is necessary for Cnn phosphorylation and correct PCM organisation, what happens when Spd-2 cannot bind Polo and what upstream regulators facilitate this interaction. Furthermore, I aim to identify the other centriole/centrosome proteins involved in Polo recruitment. To do this, I will make use of biochemical assays and advanced microscopy techniques, coupled with fly genetics and a powerful mRNA injection assay to rapidly test the effects of different mutants in fly embryos. Ultimately, I hope to be able to describe in molecular detail which proteins are phosphorylated by which kinases to allow Polo to be recruited to fulfil its many functions at the centrioles and centrosomes.