during interphase. Plkl phosphorylates Nlp and displaces it from the centrosome. 73,74
PlkI promotes the recruitment of Aurora A to the centrosome. During G2 phase, Aurora A kinase functions in the initial activation of Plkl together with Bora and contributes to centrosome maturation.75-76 Once PlkI is activated in G2 phase, continuous PlkI activity is required during mitosis.79 to maintain the PCM structure of the centrosome .78 PlkI-dependent modification ofdaughter centrioles renders the centrosomes competent for recruiting PCM proteins involved in MT nucleation during the G2/M transition.'15 PlkI is involved in the degradation of Bora in mit Minimal proteins amounts of the Aurora
A-Bora complex are sufficient to sustain PlkI activity during mitosis.80" The microtubule binding protein TPX2 is also involved in centrosome maturation through the activation of Aurora A.