Central scaffolding component of the centrioles ensuring their 9-fold symmetry (PubMed:21273447). Required for centrosome biogenesis and duplication: required both for mother-centriole-dependent centriole duplication and deuterosome-dependent centriole amplification in multiciliated cells (By similarity). Nine homodimers form a cartwheel structure with an internal diameter of 23 nM and radial spokes connecting to the microtubule triplets. Component of the deuterosome, a structure that promotes de novo centriole amplification in multiciliated cells that can generate more than 100 centrioles. The 35 nM long coiled-coil domain mediates homodimerization while the globular N-terminus links the dimers at an angle of 40 degrees to form the inner ring.