The centrosome, which acts as the main microtubules-organising centre in animal cells, presents two cylindrical structures in its core: the centrioles. In addition to their role in centrosome formation, the centrioles are crucial for the formation of mechanosensory cilia in Drosophila. The formation of the centrioles relies on a few essential factors, including the kinase Plk4. Intriguingly, the critical target site(s) of this master regulator remained to be identified. We decided to address this question by studying potential phosphorylation sites in the essential, centriolar protein Ana2. Our RNA injection assay into Drosophila embryos demonstrates the crucial role two conserved serines in Ana2 localisation. We have generated transgenic lines to study the functional importance of these sites during fly development. Finally, our results also suggest a determinant role of Ana phosphorylation on its ability to self-interact.