Plays an important role in cell division and centrosome function by participating in centriole duplication. Inhibits microtubule nucleation from the centrosome. Involved in the regulation of slow processive growth of centriolar microtubules. Acts as microtubule plus-end tracking protein that stabilizes centriolar microtubules and inhibits microtubule polymerization and extension from the distal ends of centrioles. Required for centriole elongation and for STIL-mediated centriole amplification. Required for the recruitment of CEP295 to the proximal end of new-born centrioles at the centriolar microtubule wall during early S phase in a PLK4-dependent manner. May be involved in the control of centriolar-microtubule growth by acting as a regulator of tubulin release (By similarity). Forms homodimers. Associates with microtubules plus ends; binds to beta-tubulin subunits exposed on microtubule outer surface at its distal tip; also associates with microtubule lattice. Associated with the gamma-tubulin complex. Interacts with the head domain of EPB41. Interacts with LYST. Interacts with CEP152 (via C-terminus). Interacts with STIL. Forms a complex with STIL and SASS6 (By similarity). Localized within the center of microtubule asters. During centriole biogenesis, it is concentrated within the proximal lumen of both parental centrioles and procentrioles (By similarity). Phosphorylation at Ser-590 and Ser-596 by PLK2 is required for procentriole formation and centriole elongation. Phosphorylation by PLK2 oscillates during the cell cycle: it increases at G1/S transition and decreases during the exit from mitosis. Phosphorylation at Ser-596 is also mediated by PLK4 but is not a critical step in PLK4 function in procentriole assembly. Belongs to the TCP10 family.