Essential for the assembly of the distal half of centrioles, required for centriole elongation (PubMed:19349582, PubMed:32946374). Acts as a negative regulator of centriole elongation (PubMed:37934472). {ECO:0000269|PubMed:19349582, ECO:0000269|PubMed:32946374, ECO:0000269|PubMed:37934472}. This is the function of ENSG00000152359 (POC5, POC5 centriolar protein).