Centrosomal protein required in the positioning and anchorage of the microtubule minus-end in epithelial cells (PubMed:15190203, PubMed:23386061). May also act as a centrosome maturation factor (PubMed:11956314). May play a role in microtubule nucleation, by recruiting the gamma-tubulin ring complex to the centrosome (PubMed:15190203). Overexpression does not perturb nucleation or elongation of microtubules but suppresses release of microtubules (PubMed:15190203). Required for centriole organization and microtubule anchoring at the mother centriole (PubMed:23386061).